6. LPC Bituminous Mixtures Design Guide, Sept 2007. - Aapaq.org

aapaq.org

6. LPC Bituminous Mixtures Design Guide, Sept 2007. - Aapaq.org

LPC Bituminous Mixtures Design GuideThe RST Working Group"Design of bituminous mixtures "Under the supervision ofJean-Luc DELORME,Chantal de la ROCHE,Louisette WENDLINGSeptember 2007Laboratoire Central des Ponts et Chaussées58, bd Lefebvre, F 75732 Paris Cedex 15


Jean-Luc DELORMELaboratoire Régional des Ponts et Chaussées de l’Est ParisienChantal de la ROCHELaboratoire Central des Ponts et ChausséesLouisette WENDLINGLaboratoire Régional des Ponts et Chaussées d’AutunThis report was compiled from the documents produced by and with the participationof the "Design of bituminous mixtures" working group, coordinated by Mr. Jean-Luc DELORME. Below is the list of working group members:Yves BROSSEAUD, Laboratoire Central des Ponts et ChausséesYves GANGA, Laboratoire Régional des Ponts et Chaussées de Clermont-FerrandRené HIERNAUX, Laboratoire Régional des Ponts et Chaussées de Saint-QuentinJean-François LAFON, Laboratoire Régional des Ponts et Chaussées de ToulouseFrancis MOUTIER, Laboratoire Central des Ponts et ChausséesClaude ROGER, Laboratoire Régional des Ponts et Chaussées de StrasbourgPatrick VAN GREVENYNGHE, Laboratoire Régional des Ponts et Chaussées– d’ Aix-en-ProvenceAlso providing valuable assistance with this publication were:Chantal de la ROCHE, Laboratoire Central des Ponts et ChausséesFlorence PERNOT-MOREAU, Laboratoire Régional des Ponts et Chaussées de l’EstParisienFrançois TRAVERS, Laboratoire Central des Ponts et ChausséesLouisette WENDLING, Laboratoire Régional des Ponts et Chaussées d’AutunNicole VERCHERE, Laboratoire Régional des Ponts et Chaussées de l’Est ParisienPreface contributed by:Jean-Michel PIAU, Technical Director for Pavements and Road Safety, LaboratoireCentral des Ponts et Chaussées


LPC Bituminous Mixtures Design Guide– Preface –PrefaceLPC Bituminous mixtures Design GuideJean-Michel PIAUThis guide is intended to collate and set forth the knowledge accumulated byFrance's Ministry of Public Works' Scientific and Technical Network (RST) in the fieldof designing hot bituminous mixtures.It provides a description of:⎯ the bituminous mixtures design method used by RST; and⎯ the rules of practice and expertise introduced in asphalt mix design studies,for the purpose of efficiently obtaining materials capable of meeting a seriesof predefined specifications.This document has been compiled with an educational aim of transferring knowledgeand standardizing methods currently applied within the various Ponts et Chausséeslaboratories.It would be beneficial however to expand the document scope over the near term bycontributions from the world of industry to give rise to the publication of a "Frenchmethod for road material design". This effort would allow covering the entire range oftechniques implemented throughout France capable of being shared among ourEuropean and international partners.We felt it appropriate to use this guide's introductory section to recall the mainobjectives inherent in bituminous mixtures design methods and then to explain thepredominant constituents based of a streamlined formulation, making it morestraightforward to grasp long and complex processes that often imply developingsuch methods. It then becomes easier to understand the diversity of methods in useacross the world. Highlighting the key stakes involved and the breadth of this topicstill to be explored also serves to justify the permanence of research resourcesallocated to improving and optimizing mix design methods.Along the same lines, a number of preliminary considerations will be provided belowon another aspect of this "bituminous mixtures design" focus; these concern morespecifically the mix design studies actually being conducted.–3 –


LPC Bituminous Mixtures Design Guide– Preface –The objectives behind a road material design method in the laboratory are basicallyof three types. The impetus lies in deriving and proposing materials that are:⎯ capable of being successfully implemented on a jobsite,⎯ capable of resisting the loads induced from the rest of the project works,⎯ capable of satisfying the structural durability or wearing requirements ofpavements, as specified by project developers.The quality and relevance of asphalt mix design methods exert a strong influence onuser safety, as well as on the durability and maintenance costs associated with theparticular infrastructure.Yet these methods remain valuable tools for innovation, by virtue of providing guidesfor the development and improvement of experimental materials and creating themeans for evaluating performance at an early stage and at relatively low cost.Generating a mix design method entails a long and complex process that requiresconsiderable back-and-forth between field and laboratory over an extended period oftime; broadly speaking, this approach is more heavily dependent upon the (cultural)context of pavement design methods and product standardization / classification.Bituminous mixtures design methods rely upon three cornerstones, all highlycorrelated and interdependent.The first pertains to the set P of physical, chemical and mechanical propertiesconsidered as necessary and adequate for determining the aptitude of constituentsand mixes to form proper road materials.The second cornerstone is the set E of tests and testing methods used in order tomeasure these properties.The third cornerstone is the set V of threshold values to be reached or notexceeded, depending on the properties required of the project structure over its lifecycle; these are to be included in the specifications issued by project developers.Among the first set P , it is important to distinguish between magnitudes Pcapplicable to constituents and magnitudes Pm applicable to mixes. Within the lattercategory, distinction must also be drawn between magnitudes Pv of the volumetrictype, such as the concentration modulus and void content, and performance-relatedmechanical or physical magnitudes Pf , of the empirical or intrinsic type, such asrutting resistance, fatigue resistance and stiffness modulus.Historically speaking, these methods were typically based on Pc and Pv properties,i.e. more likely to yield direct and ready-to-use design rules; they are referred to as "compositional recipe" guides.Subsequent methods sought to integrate, without completely overlooking the initialapproaches, an increasing number of performance-related magnitudes, closer toproperties that were directly representative of material behavior within structures, yetmore complicated to assess and incorporate into the actual design.The rising importance assigned today to material recycling or reuse techniques inroad construction and maintenance, which has served to broaden componentdiversity, merely strengthens the need for performance-related design methods thatfocus directly on the bituminous mixtures.–4 –


LPC Bituminous Mixtures Design Guide– Preface –The selection of tests and testing methods E associated with parametermeasurements P again offers many degrees of freedom in determining designmethods. This trend is even more pronounced given that set E also includes thechoice of specimen preparation methods, which often differ from one country to thenext 1 . It should nonetheless be pointed out that for properties P relating to Europeanstandardization, a major step forward has recently been taken by mandating a singletype of test and testing method 2 .The third cornerstone comprises the ranges of acceptable values V associated withvariables P , given the selected tests E and the particular use sought for thematerials. Making such a selection engenders considerable reflection, which typicallyinvokes a preexisting reference derived over time and based on a comparison drawnbetween field observations and design methods. For standardized materials, set V isorganized by material category, which serves to combine the target specifications forthe variables found in set P homogeneously and consistently. The application ofcorresponding product-based standards then enables streamlining project developerspecifications.Let's also point out herein that depending upon the precise needs expressed in theasphalt mix design 3 , several levels of total or partial method application are generallydefined; these would correspond with the implementation of subsets { P ',E',V '}P , E,V triad.composed within the { }Mix design studies lie within the scope framed by the methods actually used, whichtend to focus on generating materials that satisfy the specifications stipulated by theproject developer, through manipulating design variables under supervision of theproject's general contractor. Yet many other situations could also warrant the creationof design test specimens.When designing a new hot bituminous mix, set F containing designer degrees offreedom usually pertains to:⎯ the broad choices for the mix's mineral phase (filler, fines, sands,aggregates), depending on project constraints and location;⎯ choice of binder (type, hardness);⎯ the eventual introduction of admixtures (e.g. enhancers);⎯ choice of particle size distribution; and⎯ binder content.In symbolic terms, a mix design problem entails solving the following program:123Example: Depending on the country, distinction can be drawn from among four major specimenpreparation methods; using a plate compactor, compaction with the gyratory shear press,compaction by impact (rammer) or vibration.Beyond a certain number of properties, for which the corresponding tests are deemed equivalent.Design of a new material, periodic formula verification, …–5 –


LPC Bituminous Mixtures Design Guide– Preface –Find F such that P(F,E)∈Vwith:F = Design parameter valuesE = The tests and test methods employed (including specimen preparation)V = Intervals (potentially semi-infinite) of the required performance valuesP ( F,E)= Material responses, as derived according to values F with tests EThe designer's craftsmanship enters into play through minimizing the number oflaboratory tests (i.e. the number of designs undergoing testing), thereby yielding asolution to this problem.Designer expertise is often primarily implicit, based on extensive personal experienceand in-depth knowledge of road materials and of their sensitivity, in qualitative (andsometimes quantitative) terms, to design parameters.Yet most of these rules, some of which had been intentionally built on the basis ofmulti-faceted experimental programs 4 , are now understood and help stimulatelearning of the mix designer's trade. The core of the present document will lay outthese rules in detail.In contrast, the actual techniques used for solving asphalt mix design problems, asregards the current discussion, and introduced by material designers have for themost part remained implicit.In returning to the overview presented above, it can simply be stated that approachesrely for the most part on iterative "progressive" methods built from a qualitative 5 , or in∂ P(F,E)some instances quantitative, knowledge of the sensitivity matrix , thereby∂Fensuring a suitable correction of design parameters from the standpoint of narrowingthe discrepancy between the current P ( F,E)value and the target interval V . If needbe, this approach could be adopted when developing computer-aided designsoftware.45Example: The RST study entitled "Multi-year Fatigue Plan for Bituminous mixtures".∂PA qualitative knowledge of the sensitivity matrix entails knowing the algebraic sign of matrix∂Fcomponents and in some instances more than their simple orders of magnitude.–6 –


Table of ContentsPREFACE ........................................................................................................................... 3TABLE OF ILLUSTRATIONS........................................................................................... 11RÉSUMÉ ........................................................................................................................... 14ABSTRACT....................................................................................................................... 151 GENERAL REMARKS – BASES OF THE METHOD........................................... 171.1 Introduction............................................................................................................ 171.1.1 The various mix design approaches.................................................................... 171.1.2 Type testing procedures applied in France ......................................................... 191.2 Presentation of this document ............................................................................... 191.3 Test protocols in application.................................................................................. 201.3.1 Gyratory compactor............................................................................................. 211.3.2 Water resistance sensitivity................................................................................. 221.3.3 The wheel tracking test (large device)................................................................. 231.3.4 Stiffness testing ................................................................................................... 231.3.5 Fatigue resistance ............................................................................................... 251.4 General remarks on bituminous mix components ................................................. 251.4.1 Aggregates .......................................................................................................... 261.4.2 Binder .................................................................................................................. 271.4.3 Additives.............................................................................................................. 301.5 Useful definitions and relations for type testing ..................................................... 331.5.1 Binder content ..................................................................................................... 341.5.2 Richness modulus K............................................................................................ 341.5.3 Percentage of voids or compacity ....................................................................... 352 TYPE TESTING OF BITUMINOUS MIXTURES ................................................... 412.1 Prescription relative to mix components................................................................ 422.1.1 Specifications regarding added fillers................................................................. 422.1.2 Specifications regarding fillers contained in the mixture .................................... 432.1.3 Specifications regarding fine aggregates or all-in aggregate (0/4, 0/6)............... 432.1.4 Specifications regarding coarse aggregates ....................................................... 442.1.5 Specifications regarding additives....................................................................... 472.1.6 Specifications regarding binders ......................................................................... 482.1.7 Specifications regarding reclaimed asphalt......................................................... 492.2 Specifications regarding mixture composition ....................................................... 512.2.1 Grading................................................................................................................ 512.2.2 Binder content and Richness Modulus................................................................ 52–7 –


2.3 Preparation of test specimens ............................................................................... 532.3.1 Density measurements........................................................................................ 532.3.2 Procedure for reheating and incorporating mix reclaimed asphalts .................... 542.3.3 Mixing .................................................................................................................. 552.3.4 Compaction of test specimens ............................................................................ 552.3.5 Test specimen sawing and bonding .................................................................... 552.3.6 Test specimen conservation................................................................................ 552.3.7 Test specimen void percentage .......................................................................... 562.4 Execution of type testing ....................................................................................... 562.4.1 Choice of test typing level ................................................................................... 562.4.2 Level 1................................................................................................................. 572.4.3 Level 2................................................................................................................. 602.4.4 Level 3................................................................................................................. 602.4.5 Level 4................................................................................................................. 612.4.6 Additional tests .................................................................................................... 622.5 Formula verification ............................................................................................... 622.6 Type testing procedure length and required quantity of materials......................... 632.7 Summary of test characteristics and methods....................................................... 642.7.1 Asphalt mixes ...................................................................................................... 642.7.2 Very thin asphalt concretes ................................................................................. 662.7.3 Soft asphalt concretes......................................................................................... 672.7.4 Hot Rolled Asphalt............................................................................................... 682.7.5 Stone Mastic Asphalt........................................................................................... 692.7.6 Porous Asphalt .................................................................................................... 703 MIX DESIGN PROCEDURE.................................................................................. 733.1 Component selection............................................................................................. 733.1.1 Aggregates .......................................................................................................... 733.1.2 Binder .................................................................................................................. 793.1.3 Additives.............................................................................................................. 813.2 Relationships between binder properties and mix properties................................ 833.2.1 Penetrability and ring and ball temperature......................................................... 833.2.2 The SHRP criteria ............................................................................................... 833.2.3 Origin of the bitumen ........................................................................................... 843.3 Initial composition by type of material.................................................................... 853.3.1 Asphalt Concretes for base course – Grave-Bitume AC-GB and HighModulus AC-EME............................................................................................... 853.3.2 Thick layer mixtures for surface or binder course – AC-BBSG, AC-BBS,AC-BBME ............................................................................................................ 903.3.3 Porous asphalt mixes – PA-BBDr........................................................................ 923.3.4 Thin asphalt mixes – AC-BBM, BBTM and mixes for UTLAC (BBUM) ............... 953.3.5 Stone Mastic Asphalt - SMA................................................................................ 983.4 Composition adjustments ...................................................................................... 993.4.1 Effect of mix variables (general remarks).......................................................... 1003.4.2 Effect of dimension D ........................................................................................ 1003.4.3 Effect of granular proportions ............................................................................ 100–8 –


3.4.4 Discontinuity ...................................................................................................... 1003.4.5 Incorporation of rounded particle aggregate ..................................................... 1013.4.6 Percentage of fillers........................................................................................... 1013.4.7 Percentage of bitumen ...................................................................................... 1013.5 Gyratory Compactor compactibility study ............................................................ 1013.5.1 General remarks................................................................................................ 1013.5.2 Percentage of voids vs. number of gyrations .................................................... 1023.5.3 Percentage of voids at a given number of gyrations ......................................... 1033.5.4 Percentage of voids at 10 gyrations: v 10............................................................ 1043.5.5 Percentage of voids at 1 gyration: v 1................................................................. 1043.5.6 Slope K 1............................................................................................................. 1043.5.7 Pseudo shear stress τ ....................................................................................... 1053.5.8 Test precision .................................................................................................... 1063.5.9 Correction of mix composition ........................................................................... 1063.6 Mix performance.................................................................................................. 1103.6.1 Resistance to permanent deformation on the LPC Wheel Tracking Tester ...... 1103.6.2 The Duriez test (Method B of EN 12697-12) ..................................................... 1143.6.3 Stiffness modulus .............................................................................................. 1163.6.4 Fatigue .............................................................................................................. 1213.6.5 Texture .............................................................................................................. 1223.6.6 Ancillary tests .................................................................................................... 1233.7 Practitioners' advice ............................................................................................ 1243.7.1 Effect of mix design factors – Summary............................................................ 1243.7.2 Practical tips for the mix designer ..................................................................... 1254 RELATIONSHIPS BETWEEN LABORATORY AND FIELD RESULTS ............ 1274.1 Percentage of voids measured with the Gyratory Compactor (GC) .................... 1274.1.1 Experimental objective ...................................................................................... 1274.1.2 Results .............................................................................................................. 1284.1.3 Comments ......................................................................................................... 1314.2 Large device wheel tracking test ........................................................................ 1324.2.1 The studies conducted in France ...................................................................... 1324.2.2 Colorado study .................................................................................................. 1344.2.3 Ranking of mix rutting behavior......................................................................... 1354.3 Stiffness modulus test ......................................................................................... 1364.3.1 Experimental objective and procedure .............................................................. 1364.3.2 Results .............................................................................................................. 1374.4 Fatigue test.......................................................................................................... 1404.4.1 Experimental objective and procedure .............................................................. 1404.4.2 Results obtained................................................................................................ 1404.5 Synthesis of the relationships between laboratory and field results .................... 1425 CONCLUSION .................................................................................................... 143Bibliography..................................................................................................................... 144Appendix A: List of normative references required for the type testing phase ................ 149–9 –


Appendix B: EN testing standards - EN 12697 series: "Asphalt mixes"Use recommendations................................................................................ 154Appendix C: Equivalence table between TL ext and B int .................................................... 159Appendix D: Main test precisions .................................................................................... 160Appendix E Summary table – Specifications and recommendations for each typeof material................................................................................................... 162APPENDIX F ................................................................................................................... 164Appendix G Glossary ...................................................................................................... 175Index .......................................................................................................................... 197–10 –


Table of illustrationsFigure 1: Gyratory Compactor – MLPC Type 2 ....................................................... 21Figure 2: Gyratory Compactor – MLPC Type 3 ....................................................... 21Figure 3: Large-device wheel tracking test ............................................................... 23Figure 4: Detail of the rut depth measurement ......................................................... 23Figure 5: Complex modulus testing machine - MLPC 3MC ..................................... 24Figure 6: Adjustment of the displacement sensor..................................................... 24Figure 7: Rheologically-controlled testing machine .................................................. 24Figure 8: Specimen set-up........................................................................................ 24Figure 9: Fatigue test in 2-point bending on trapezoidal specimens......................... 25Figure 10: View of quarry face.................................................................................. 26Figure 11: Screening-crushing.................................................................................. 26Figure 12: Penetrability test...................................................................................... 30Figure 13: Ring and ball temperature test ................................................................ 30Figure 14: Example of extraction on Trinidad Lake (Venezuela) .............................. 32Figure 15 : Examples of colored asphalt mixes ........................................................ 33Figure 16: Volumetric approach to developing an asphalt mix ................................. 36Figure 17: Connecting, non-connecting and occluded voids .................................... 37Figure 18: Summary diagram of the various type testing levels ............................... 57Figure 19: Small-scale rutting tester model operating in air...................................... 70Figure 20: Cross-section of a Grave-Bitume AC-GB mix.......................................... 85Figure 21: Cross-section of a AC-BBSG (Asphalt Concrete BétonBitumineux Semi-Granular) .................................................................... 90Figure 22: Surface appearance of a AC-BBSG (Asphalt Concrete BétonBitumineux Semi-Granular) .................................................................... 90Figure 23: Cross-section of a Porous Asphalt .......................................................... 92Figure 24: Surface appearance of a Porous Asphalt (PA-BBDr) .............................. 92Figure 25: Cross-section of a Thin Layer Asphalt Concrete (AC-BBM) .................... 95Figure 26: Surface appearance of a Thin Layer Asphalt Concrete (AC-BBM).......... 95Figure 27: Cross-section of an SMA (Stone Mastic Asphalt).................................... 98Figure 28: Surface appearance of an SMA (Stone Mastic Asphalt).......................... 98Figure 29: Nomograph for calculating mix stiffness modulus values ...................... 119Figure 30: Example of GC variability in the percentage of voids obtained onsite ... 129Figure 31: LCPC Fatigue Carousel......................................................................... 132Figure 32: Results obtained with the Large Device wheel tracking Tester -Study of laboratory rutting..................................................................... 133Figure 33: Results obtained with the Large Device wheel tracking Tester -Study of rutting on plant-produced mixes ............................................. 133Figure 34: Behavior of mixes on the LCPC test carousel, evolution of rut depthsubmitted to a single large wheel (F = 42,5 kN, V = 40 km/h) .............. 134Figure 35: In situ core sampling.............................................................................. 136Figure 36: In situ sawing......................................................................................... 136Figure 37: Variability in stiffness modulus on in situ extractions (site no, 1) ........... 137Figure 38: Variability in stiffness modulus on in situ extractions (site no, 2) ........... 137Figure 39: Laboratory-worksite correlation: Stiffness modulus at 15°C(0,02 sec or 10 Hz) ............................................................................... 139Figure 40: Summary of fatigue test results by sample preparationprotocol (preliminary design, laboratory verification, onsiteextractions) ........................................................................................... 140–11 –


Table 1 – Typical filler characteristics for asphalt mixtures....................................... 43Table 2 – Specification on fines from fine aggregate or all-in aggregate or(in their absence) from mixed fillers......................................................... 43Table 3 – Indicative minimum characteristics of coarse aggregates : Mechanicalstrength and production characteristics ................................................... 46Table 4 – Accepted values of D vs. type of mixture.................................................. 47Table 5 – Reclaimed asphalt characteristics vs. reuse rate...................................... 51Table 6 – Overall limits of target composition........................................................... 52Table 7 – Minimum Binder content and richness modulus values ............................ 53Table 8 – Test specimen characteristics .................................................................. 56Table 9 – Specifications relative to the void percentage........................................... 58Table 10 – Specifications relative to water resistance .............................................. 59Table 11 – Specifications relative to the wheel tracking test..................................... 60Table 12 – Specifications relative to the stiffness modulus....................................... 61Table 13 – Specifications relative to fatigue resistance ............................................ 61Table 14 – TYPE TESTING Required material quantities – Approximate testingdurations.................................................................................................. 63Table 15 – Types of tests for asphalt mixes ............................................................. 64Table 16 – Type of tests for BBTM (very thin layer asphalt concretes) .................... 66Table 17 – Type of tests for soft asphalt concretes .................................................. 67Table 18 – Type of tests for Hot Rolled Asphalt ....................................................... 68Table 19 – Type of tests for the Stone Mastic Asphalt material................................ 69Table 20 – Type of tests for the porous asphalt........................................................ 70Table 21– Suggested bitumen grade by mix type..................................................... 80Table 22 – Initial AC20 or AC14 Grave-Bitume A C-GB and High ModulusAsphalt Concrete AC-EME grading curve.............................................. 87Table 23 – Initial AC10-EME grading curve.............................................................. 87Table 24 – Typical initial binder content of AC-GB and AC-EME(richness modulus) .................................................................................. 88Table 25 – Initial AC-BBSG, AC-BBS and AC-BBME grading curve ........................ 91Table 26 – Initial BBSG, BBME and BBS richness modulus and binder content...... 92Table 27 – Initial PA-BBDr grading curve ................................................................. 93Table 28 – Initial Porous Asphalt (PA-BBDr) binder content (Richness modulus) .... 95Table 29 – Initial AC-BBM and BBTM grading curve................................................ 97Table 30 – Initial AC-BBM, BBTM and mixes for UTLAC (BBUM) binder content .... 98Table 31 – Initial SMA grading curve........................................................................ 99Table 32 – Initial SMA binder content....................................................................... 99Table 33 - Composition effect on Gyratory Compactor test results ........................ 109Table 34 - Composition adjustment in order to correct Gyratory Compactorresults .................................................................................................... 110Table 35- Effects of mix design factors on % rutting............................................... 113Table 36 - Practitioners' advice - Enhancing rutting resistance .............................. 113Table 37 - Typical © values (in MPa)...................................................................... 115Table 38 - Practitioners' advice - Duriez test results adjustment ............................ 115Table 39 - Fatigue - loss of linearity relationship .................................................... 121–12 –


Table 40 - Adjustment to average texture depth..................................................... 123Table 41 - Practitioners' advice – Mix refinement [for a given type of mix] –Summary of the effect of mix design factors.......................................... 124Table 42 - Site conditions ....................................................................................... 128Table 43 - % of void measurements – Comparison of laboratory compactor results(design, verification) with onsite results (Gyratory compactor, bulk density(MVA) measurement using gamma-densitometry) ................................ 130Table 44 – Comparison between the field behavior of material mixes and theacceptance or rejection criterion according to French specifications..... 135Table 45 – Test repeatability and reproducibility values ......................................... 160–13 –


LPC Asphalt Mix Design Guide- Résumé/Abstract -RésuméManuel LPC d’aide à la formulation des enrobésJean-Luc DELORMEChantal de La ROCHELouisette WENDLINGLe manuel LPC d’aide à la formulation des enrobés est destiné aux laboratoires quimettent au point des mélanges hydrocarbonés.La méthode de formulation fait appel aux caractéristiques des constituants, à latenue à l’eau, au pourcentage de vides à la Presse à Cisaillement Giratoire, à larésistance à l’orniérage, au module de rigidité et à la résistance en fatigue.Les exigences normatives nécessaires à la réalisation d’une épreuve de formulationsont synthétisées dans la deuxième partie. Elles tiennent compte de l’expériencefrançaise et de l’application des normes européennes.La partie consacrée à la mise au point des mélanges est fondée sur l’expérience duréseau LPC, exprimée à partir des résultats d’un groupe de travail, elle comporte desrecommandations pour optimiser les caractéristiques du matériau.Ces recommandations s’appuient sur des cas concrets, sur des plans d’expériencespécifiques ou font appel à des références bibliographiques.Les relations entre les caractéristiques de laboratoire et celles obtenues sur chantierproviennent de travaux de recherche LPC réalisés sur les matériaux structurants. Ilspermettent de faire la relation entre une population de résultats de laboratoire et unepopulation de résultats de chantier sur les pourcentages de vides à la Presse àCisaillement Giratoire, l’orniérage, le module et la résistance en fatigue des enrobés.–14 –


LPC Bituminous Mixtures Design Guide- - Résumé/Abstract -AbstractLPC Bituminous Mixtures Design GuideJean-Luc DELORMEChantal de La ROCHELouisette WENDLINGThis LPC Mix Design Guide is intended for road research laboratories assigned todesign bituminous materials mixesThe mix design methodology is based on component characteristics, water-sensitivitytesting, void content assessments using gyratory compaction, resistance topermanent deformation, stiffness and fatigue resistance.Normative requirements by type of test will be summarized in the second part takinginto account the French experience and the European standardization.The part of this report devoted to the actual mix design is based on the experience ofa working group from the LPC network and includes recommendations for optimizingmaterial characteristics. Such recommendations are based on practical cases,specific experiments or bibliographical research.Relationships between laboratory characteristics and jobsite characteristics havebeen established from LPC studies on structural materials; they serve to correlate adataset of results obtained in the laboratory with another set obtained on the jobsite,with respect to void content, by means of gyratory compaction, rutting resistance,stiffness and fatigue resistance.–15 –


LPC Bituminous Mixtures Design Guide– General remarks –1 GENERAL REMARKS – BASES OF THE METHOD1.1 Introduction1.1.1 The various mix design approachesDesign methods for bituminous mixes have been developed over the past forty yearsin order to satisfy the latest requirements issued by road builders and engineeringcompanies. Rising traffic loads, along with the integration of safety, comfort,durability, maintenance and user nuisance considerations, under given climaticconditions and within a defined technical context (design and dimensioning ofpavements layers), has incited increasingly-complex material design approaches.Asphalt mix design becomes even more sophisticated in improving onecharacteristic, while changing the composition exerts a negative influence on anothercharacteristic. One well-known example is that an increase in binder content has abeneficial impact on fatigue resistance, yet diminishes rutting resistance.The properties sought for a given bituminous material depend on the intended layerof application. For bases and base-courses, whose role is to distribute loads over thesupporting soil without incurring excessive deformation, the overlay course mustbasically be stiff, fatigue-resistant, resistant to permanent deformations and relativelycompact. For a wearing course in direct contact with traffic and aggressive climaticagents, emphasis is placed on: durability with a high resistance to water action,resistance to permanent deformations, and especially on the search for satisfactorysurface characteristics (roughness, rolling noise, photometry, etc.). Furthermore,depending on the specific design case, the wearing course must be compact enoughto protect the lower layers from water infiltration, yet open enough to enable water todrain. The characteristics sought are multifaceted and sometimes contradictory.This topic has been addressed in a variety of ways and depends heavily on the localcontext. A state-of-the-art assessment of asphalt mix design procedures acrossvarious countries was produced within the scope of a RILEM technical committeework program [Rilem Report 17, 1998] and distinguished six design methods:1. "recipe ",2. empirical testing,3. analytical computations,4. volumetric method,5. performance related testing, and6. fundamental testing.- 17 -


LPC Bituminous Mixtures Design Guide– General remarks –The (cookbook) recipe method relies upon local experience a known composition,which has already yielded satisfactory results under a given set of use conditionsover long periods of time, is reproduced. The application of such cookbook recipescould, on occasion, be supplemented by a handful of tests stemming from empiricalmethods.The most widespread method employing empirical tests is known as Marshall'smethod [ASTM DI-559-60T]. Specimens are compacted according to establishedoperating procedures, and mechanical test results are compared with observed onsitebehavior.The analytical method is based on component properties and a mix model for bothcalculating the percentage of voids and estimating material performance. Thismethod has been developed primarily in Belgium.The volumetric method consists of deducing the respective proportions, expressed involume terms of the granular skeleton, the bitumen and the available volume(percentage of voids) of a compacted specimen under previously-establishedconditions; this allows determining mix behavior without conducting any additionalmechanical tests.The performance related method that calls for conducting tests on the basis ofmaterial properties makes use of simulation techniques, directly correlated with thetarget property; such is the case with the rutting test, run like a traffic simulation.The so-called "fundamental" method comprises tests whose results may be directlyused as input data into material design models. This would specifically pertain todynamic modulus or fatigue resistance values.European standardization of hot bituminous mixtures has served to formalize andsummarize the principles behind this classification, by means of distinguishingbetween two approaches: "empirical" and "fundamental".The empirical approach contains the "recipe" or "prescriptive" phase (to a ratherconsiderable extent), the "volumetric" phase, the "empirical testing" phase and,where applicable, "performance related" tests.The fundamental approach encompasses a scaled-back "prescriptive" ("prescription")phase, a "volumetric" phase, "performance related" tests and "fundamental" tests.The two approaches cannot neglect a descriptive section devoted to constituentcharacteristics, especially aggregates, given that the properties targeted by thefundamental tests are not always sufficient to satisfy the desired set of requirements.Mix design work is performed on materials either recomposed in the laboratory orextracted directly following fabrication at the plant.Two phases can in fact be distinguished under the heading of material mix design:type testing, and refinement or optimization of the mix design formula. Type testing istypically performed according to a formalized protocol since it often serves as thebasis for contractual relations, whereas the formula optimization phase (mix design)relies upon the experience of the mixtures designer.- 18 -


LPC Bituminous Mixtures Design Guide– General remarks –European standardization clearly distinguishes type testing, which lies within theregulatory domain to substantiate "EC" branding policy, from non-codified formulaoptimization (mix design).Some design methods contain both the testing part and the optimization part. Such isthe case for example with both the Marshall method, which actually predicts apossible optimization (based on the percentage of voids, stability and creep), and the"Superpave" method (optimization of the percentage of voids and binder content, asa function of expected traffic).1.1.2 Type testing procedures applied in FranceThe type testing procedure applied on French roads is defined by appropriatestandards; it has been characterized by an approach based to the greatest extentpossible on asphalt mix performance. For structural type materials, it may beclassified within the "fundamental" approach. For other material types, the approachis qualified as empirical, as intended in the European standardization, even though itinvolves “performancerelated" testing. The recipe method is not used herein. Incontrast, volumetric considerations have been taken into account by means of thegyratory compactor: this test serves as the focal point of the method since it is usedfor all types of hot bituminous mixtures (with the exception of mastic asphalts mixes,which remain beyond this document's scope of application). Type testing isconducted with materials prepared in the laboratory representative of the plannedjobsite and that expose performance thresholds.Type testing imposes specifications on the components, and especially on theaggregates. It relies upon tests on the gyratory shear press, water resistance, ruttingresistance, stiffness modulus and fatigue resistance.The mix design method is entirely dissociated from type testing and has not beencodified.The approach based on this principle has been practiced for the past thirty years; itwas first formalized in a series of SETRA-LCPC technical documents and then in theFrench standards. The current European standards, which are replacing the Frenchstandards, do not challenge this principle.1.2 Presentation of this documentThis asphalt mix design guide has been drawn up from the conclusions forwarded bythe working group introduced in the preface. This effort was complemented, inparticular for Part 4, by results from research conducted within the framework ofspecific LCPC programs (Research topic CH15: Design of the hot bituminousmixtures).In this introductory part, the operating principle behind the tests selected will bebriefly recalled, along with the set of definitions and relationships necessary forconducting type testing or bituminous mixtures design. Other definitions have beenincluded in the glossary, see Appendix F.- 19 -


LPC Bituminous Mixtures Design Guide– General remarks –Part 2 is devoted to type testing, which is fully defined within the standard reference.Test standards associated with applicable reference systems have been listed inAppendix A, and the list of current standards in effect is provided for asphalt mixcomponents (aggregates, bitumen), preparatory tests, the actual tests,methodological references stemming from either the specific standards derived orgeneral standards.Depending on the level of requirements, the sample contains a varying number oftests with thresholds ranging in severity depending on material use and type. Yetthese test results are always accompanied by requirements issued on thecomponents, particularly the aggregates. Part 2 offers a summary of the existinginventoried requirements, at times shared among different documents. Europeanstandards are taken into consideration in this part. The list of European standardswith their French correspondence will constitute Appendix B, along with pertinentapplication recommendations and comments. When European standards give rise tomodifications, all relevant chapters will be highlighted.The objective of Part 3 is to lay out the formula optimization and adjustment methodsin practice throughout France's Ponts et Chaussées (LPC) research network.Indications will be given regarding the choice of constituents and test resultinterpretations, especially those from the gyratory shear press, in order to derive amix that fulfills all target characteristics. Recommendations will be provided foradjusting the asphalt mix composition whenever test results on a given study mix arenot satisfactory. This part has been written using the results from specificexperimental campaigns or as a means of transmitting the practices set forth eitherby experts working with the laboratory network or in bibliographical references.Part 4 focuses on pertinent laboratory-worksite correlations.Since the type testing specified in works contracts is conducted entirely in thelaboratory, it proves essential to ensure that the "industrial" production of roadoverlays on site enables obtaining equivalent characteristics at the worksite. Thischapter will discuss the results generated within the scope of research project CH15:"Design of hot bituminous mixtures", for the percentage of voids with the gyratorycompactor, stiffness modulus and fatigue resistance values.1.3 Test protocols in applicationThe primary tests used for type testing will be outlined below. The French andEuropean reference standards are listed in Appendices A and B, respectively.These tests have given rise to precision experiments in order to determine theirrepeatability r and reproducibility R.Repeatability r and reproducibility R measures have been summarized inAppendix D.- 20 -


LPC Bituminous Mixtures Design Guide– General remarks –1.3.1 Gyratory compactorOperating principle: The hydrocarbon mix, prepared in the laboratory, is set, bulkedand brought to the test temperature (approx. 130° to 160°C) within a cylindrical mold150 or 160 mm in diameter. A 0,6-MPa vertical pressure is then applied on the top ofthe specimen. At the same time, the specimen is slanted slightly at an angle on theorder of 1° (external) or 0,82° (internal) and submitted to circular movement. Thesevarious actions exert a compaction by means of kneading. The increase incompactness (i.e. via the decrease in percentage of voids) vs. the number ofrevolutions can then be observed.Interpretation: For a given number of gyrations, to be determined depending on thetype of mix, the nature of aggregates and the application thickness, the materialsdesigner is able to predict the percentage of voids on site. In the case of very thinwearing courses, this test focuses more on estimating the macro-texture than thecompacity.Figure 1: Gyratory Compactor –MLPC Type 2Figure 2: Gyratory Compactor –MLPC Type 3The test is highly sensitive to mix design factors, such as "friction" of the granularskeleton (angularity) and binder content.This test also serves to detect and assess the risk of rutting.- 21 -


LPC Bituminous Mixtures Design Guide– General remarks –Thanks to the speed offered by this means of testing, the gyratory compactor provesa highly-valuable instrument for the materials designer.Moreover, it enables detecting the type of changes that go unnoticed during morecommon tests conducted on aggregates. The gyratory shear press makes it possibleto verify formula consistency over time.Specifications are applicable to all types of bituminous mixtures; they stipulate arange of void percentages to be respected for a given number of gyrations.1.3.2 Water resistance sensitivityWater resistance is at the bases of the bituminous mixtures durability. It used to bemeasured by means of the Duriez test, within the scope of French standardizationpractices. However, the European standardization includes two different proceduresindirect tensile test and direct compression test derived from Duriez test.Those two procedures give equivalent results, however the repeatabilityreproducibility of the direct compression test (Duriez test) are about twice better theones of the indirect tensile test.1.3.2.1 Direct compression test (Duriez test)Operating principle: The hydrocarbon mix is compacted in a cylindrical moldundergoing double-effect static pressure. A group of specimens is conserved withoutany controlled temperature immersion (18°C) or relative humidity immersion, whilethe other group is held immersed. Each specimen group is then loaded under simplecompression.Results interpretation: The ratio of resistance following immersion to dry resistanceyields the water resistance value for the mix. Dry resistance represents one approachto describing mechanical characteristics, while compacity constitutes acomplementary indicator to the gyratory test.1.3.2.2 Indirect tensile testOperating principle: Cylindrical specimens are either produced with the gyratorycompactor or cored from plates. A group of the specimens is conserved withoutimmersion at room temperature, while the other portion is held immersed afterextensive degassing during 70 hours at 40°C. Each specimen group is then loadedunder diametric compression at 15°C.Test interpretation: The ratio of the resistance post-immersion to the dry resistanceyields the mix's water resistance.- 22 -


LPC Bituminous Mixtures Design Guide– General remarks –1.3.3 The wheel tracking test (large device)Operating principle: The test specimen here is a parallelepiped plate 5 cm or 10 cmthick, depending on whether the application thickness of the mix happens to be lessthan or greater than 5 cm. This plate is submitted to a one-wheel traffic load(frequency: 1 Hz, load: 5 kN, pressure: 0,6 MPa) under severe temperatureconditions (60°C).Test interpretation: The depth of deformation produced when the wheel crosses overthe bituminous mixture is measured vs. the number of cycles. Test specificationspertain to a rut percentage at a given number of cycles, which in turn depends on thetype of material and its classification.Figure 3: Large-device wheel tracking testFigure 4: Detail of the rut depth measurement1.3.4 Stiffness testingOperating principle: Asphalt mix stiffness is determined by either a complex modulustest (sinusoidal loading on a trapezoidal or parallelepiped specimen) or a uniaxialtensile test (on a cylindrical or parallelepiped specimen). The load is applied over adomain of small deformations, through controlling time or frequency, temperature,and the loading law.Test interpretation: The modulus (stress-strain ratio) is computed for each basic test.Using the time-temperature equivalence, the modulus master curve is plotted at agiven temperature. This depiction provides information on bituminous mixturebehavior over a broad load or frequency time spectrum.- 23 -


LPC Bituminous Mixtures Design Guide– General remarks –The test specification pertains to the modulus at 15°C and a frequency of 10 Hz or aloading time of 0,02 sec.Figure 5: Complex modulus testing machine -MLPC 3MCFigure 6: Adjustment of the displacementsensorFigure 7: Rheologically-controlled testingmachineFigure 8: Specimen set-up- 24 -


LPC Bituminous Mixtures Design Guide– General remarks –Fatigue resistanceOperating principle: A trapezoidal specimen is submitted, at a set temperature andloading frequency, to an imposed deformation. When the stress applied to maintain aconstant deformation is halved, the specimen is considered damaged at thecorresponding number of loading cycles.Test interpretation: On a lg/lg graph, the various couples (loading level, number ofcycles until reaching damage) may be presented on a fatigue line.Once 10 6 cycles have been completed, the loading threshold read on the line is theFigure 9: Fatigue test in 2-point bending on trapezoidal specimens1.4 General remarks on bituminous mix componentsBituminous mixes are composed of a mix of aggregate particles whose size variesbetween 0 and D (mm) and a hydrocarbon binder. Additives may be included in thismix in order to improve performance. The final mix, once compacted and cooled,features a nonzero void content, which serves to enhance product performance.- 25 -


LPC Bituminous Mixtures Design Guide– General remarks –1.4.1 AggregatesFigure 10: View of quarry faceFigure 11: Screening-crushing1.4.1.1 FillersThe fines content (i.e. passing the sieve 63 µm) of a bituminous mixture is generallya combination of added filler in small proportion and a majority of fines coming fromfine aggregates (or all in aggregates 0/4).The added filler may stem from solid rocks: limestone filler is used extensively. Othermaterials also get employed, such as cement, quicklime, activated filler (mix oflimestone fines and hydrated lime), hydrated lime, fly ash, cement fillers and slates.1.4.1.2 Fine aggregates 0/2 and all in aggregates 0/4Crushed 0/2 fine aggregates with a fine content of 18% and crushed 0/4 all inaggregates with a fine content of 10% to 14 % are mostly often used for the roadconstruction. The particle size distribution (grading) of a mix with fine aggregates(and/or all in aggregates 0/4) and coarse aggregates from different origins mighttherefore display anomalies (discontinuities or lumps).Fine aggregates with totally round particles are also used in order to improve mixworkability.1.4.1.3 Coarse aggregateCoarse aggregate (d/D) constitute the "backbone" of the hydrocarbon mix. As such,their composition, angularity and shape all serve to influence, at least in part, bothmix stability and the surface characteristics of surface courses. Moreover, theirmineralogical nature exerts a direct impact on the mix design: some materials (basalt,granite, gneiss) are more difficult to compact, while others exhibit an absorbentcharacteristic (basalt, slag, dolomitic limestone), which must be taken into account- 26 -


LPC Bituminous Mixtures Design Guide– General remarks –when deriving binder concentration. The mineralogical nature and state of cleanlinessalso influence bitumen-aggregate adhesion.1.4.1.4 Particle size distribution curvesThe ultimate granular material is obtained by mixing various granular fractions (d/D)entering into the composition. Each fraction is characterized by a particle sizedistribution that indicates the passing percentages through the range of standardizedsieves 6 . The particle distribution curve or grading curve is characteristic of the finalmaterial.1.4.2 BinderThe binder may be either a pure, modified or special bitumen (hard, pigmentable,colored bitumen, or regeneration binders), or a synthetic binder. In the absence ofother data, bitumen mass density is set equal to 1,03 Mg/m 3 .1.4.2.1 Pure bitumenThis category comprises the range of standardized paving grade bitumen accordingEN 12591 and those special bitumens distinguished by “hard” grade accordingEN 13924, and low thermal susceptibility bitumens.1.4.2.2 Modified bitumenModified bitumen materials consist of bituminous binders whose properties havebeen modified through the use of a chemical agent, which when introduced into thebasic bitumen modifies the chemical structure and physical and mechanicalproperties. This category of material has been codified in EN 14023, which remainsmore of a description than any actual performance-based classification.These bitumens are prepared prior to application within a specialized unit. Thechemical agents employed include natural rubber, synthetic polymers, sulfur andother organic-metallic compounds. The primary chemical agents used to modifybitumens are :• The Thermoplastic elastomeric polymersSBS (Styrene Butadiene Styrene)SIS (Styrene Isoprene Styrene)SB (Styrene Butadiene)SBR (Statistical copolymer)• Thermoplastic plastomeric polymersEVA (Ethylene vinyl acetate)EMA (Ethylene methyl acrylate)EBA (Ethylene butyl acrylate)PIB (Polyisobutylene)• Latex6The base series of the sieve is composed of the following elements (in mm): 0,063; 0,125; 0,250;0,500; 1; 2; 4; 8;16; 31,5.- 27 -


LPC Bituminous Mixtures Design Guide– General remarks –PolychloropreneSBR rubberNatural rubberCrumb rubberElastomer-modified binders:Physical mixes are to be distinguished from elastomeric bitumens obtained by meansof cross-linking.Physical mixes are typically heterogeneous to a scale of several micrometers. Thefineness of the elastomeric bitumen structure will exert a direct influence both on thestability of the asphalt mixture and on its physical properties over the entiretemperature range.Cross-linked elastomeric bitumens exhibit a structure resulting from a dual form ofextremely fine links, on the order of one micrometer. This reaction is irreversible.Cross-linked elastomeric bitumen displays higher tensile strength and stiffness andincreased ductility in comparison with the initial binder.Elastomeric bitumen modification induces differences in rheological behavior. Incomparison with pure bitumen, BmP SBS at low temperature exhibits lower modulusvalues, hence greater flexibility; this situation becomes reversed at hightemperatures. For a given bitumen sample, this modification in rheological behaviordepends on both polymer nature and content.Plastomer-modified binders:Ethylene copolymer bitumen (EVA, EMA and EBA):At low polymer content (< 5%), the modification in material properties is due primarilyto the increase in asphaltene concentration within the bitumen phase. In this case,the choice of the base bitumen is predominant.At high polymer levels, the polymer component is plasticized by a fraction of themaltenes found in the bitumen and the choice of polymer influences binderproperties. A decrease in penetrability coupled with a strong increase in ring and balltemperature can be observed.Ethylene – polybutylene (PIB) copolymeric bitumens:The addition of PIB in road bitumen materials serves to lower the vulnerability to coldweather.The joint use of PIB and EVA enables improving simultaneously the behavior at bothhigh and low temperature.With the exception of PIB-EVA binders, copolymeric bitumen mixes are rarely stablewhen stored (except for content levels < 3% EVA and binders with low asphalteneconcentrations). It thus becomes necessary to stir or remix the binder.Rubber bitumen:Non-storable rubber bitumen:Produced using a crumb rubber obtained by means of grating both natural andsynthetic rubber, rubber bitumen displays an elastomeric characteristic, along with- 28 -


LPC Bituminous Mixtures Design Guide– General remarks –significant viscosity at high temperature and considerable flexibility at lowtemperature.Storable rubber bitumen:Produced using ground worn tires from trucks and cars, heavy oil and a syntheticelastomer, rubber bitumen displays extreme elongation upon failure at lowtemperature.1.4.2.3 Pigmentable bitumenThis category of bitumens is obtained from untreated material samples andcharacterized by a very low asphaltene content. The grades are the same as withconventional road bitumens.The material is colored by means of metallic oxides at an approximate massconcentration of 2,5% to 6% of the total mixture.1.4.2.4 Synthetic bindersThese binders are obtained by mixing petroleum and petrochemical fractions withoutasphaltenes. They appear as a thin transparent film, which makes it possible to retainthe natural hue of the aggregate; moreover, they can be colored by adding 2%pigments.1.4.2.5 Bituminous binders with mineral loadsThese ready-to-use binders are obtained as a plant mix using pure bitumen andmineral loads, e.g. lime. Binder content differs from bitumen content.1.4.2.6 Agrochemical bindersThese binders are made from vegetal matter without any petrochemical byproduct.The result is transparent and may be colored. Its applicability is currently undergoingevaluation.1.4.2.7 Kerosene-proof bitumenThese bitumens have been specially designed to withstand the risk of dissolution dueto kerosene losses on parking surfaces and on airport strips/runways. They may beapplied in the composition of airport asphalt concretes.1.4.2.8 Rule for bitumen mixesIt may prove useful to conduct certain tests on the basis of recomposedbitumens with known penetrability or ring and ball temperatures (e.g. fora rutting test using a bitumen with a preset ring and ball temperaturevalue).- 29 -


LPC Bituminous Mixtures Design Guide– General remarks –Penetrability:100 x log P = a log P1 + b log P2where a and b are the respective proportions of 2 bitumens withpenetrability values of P1 and P2.Ring and ball temperature:100 T = a T1 + b T2a and b are the respective proportions of 2 bitumens with ring andball temperatures T1 and T2 (in °C).Figure 11: Penetrability testFigure 12: Ring and ball temperature test1.4.3 AdditivesAdditives are intended to improve asphalt mix properties. They may be introducedeither into the formula at the time of mixing or directly into the bitumen tank.1.4.3.1 Adhesion enhancersIn order to improve the reciprocal affinity between binder and aggregates whileensuring durability, adhesion enhancers may be employed. This category of additivepertains essentially to tensioactive nitrogen compounds derived from fatty acids(e.g. amines, polyamines…) with a bitumen concentration of approximately 0,3% to0,6%. The lime or limestone fines, with concentrations reaching 1% bitumen, canalso be used as such adhesion enhancing agents.1.4.3.2 PolyethyleneOrigin: cable waste material, crushed milk bottles, polyethylene films, newpolyethylene.- 30 -


LPC Bituminous Mixtures Design Guide– General remarks –Polyethylene wastes often consist of a mix of high-density and low-densitypolyethylene. During melting at temperatures of around 130°C, polyethylene getspartially combined with bitumen. The concentration tends to lie between 0,4% and1% of the aggregate quantity. The proportion of polyethylene with respect to bitumencan thus vary from 20% to 66%.1.4.3.3 PolymersPolymers assume the form of pellets incorporated during the mixing stage.1.4.3.4 Crumb rubber and 2/6 rubber aggregatesIncorporated into the formula upon mixing, the rubber is partially combined withbitumen. The manufacturing temperature is greater than that of pure bitumen, withthe mass density of rubber being 1,15 g/cm 3 .1.4.3.5 New fibers and recyclingFibers can be mixed in with the binder either as a preliminary step, or introduced intothe dry mix, or following incorporation of the bitumen.Depending on the type of fiber, the laboratory preparation procedure must beadapted while respecting the mode of industrial addition.Various types of fibers are used with this configuration:GlassThese are inorganic fibers with a length of between 100 µm and 10 mm, and adiameter on the order of 5 µm to 6 µm.The choice of surface treatment influences the induced properties. Typicalconcentrations amount to around 0,8% with respect to aggregate quantity. Theirmass density equals 2,5 g/cm 3 and their theoretical specific surface area is 0,3 m 2 /g.CelluloseThis is a natural fiber with a length of between 900 µm and 1,1 mm, and a diameteron the order of 15 - 50 µm. It may be pre-mixed in the form of pellets with a maximumconcentration of 0,3% of aggregate quantity. Mass density equals 0,9 g/cm 3 and thetheoretical specific surface area reaches 0,16 m 2 /g.Rock fibersThis category of mineral fibers features a length lying between 200 µm and 2 mm,and a diameter in the range of 3 to 5 µm. Mass density stands at 2,7 g/cm 3 and thetheoretical specific surface area at 0,6 m 2 /g.PolyesterThese fibers are synthetics with a length of between 600 µm and 1,2 mm, and insome instances may even reach 6 mm. They can withstand temperatures of up to220°C, with a concentration on the order of 0,6% of the aggregate quantity.CompositeThese fibers stem from recycled products, e.g. automobile parts.- 31 -


LPC Bituminous Mixtures Design Guide– General remarks –1.4.3.6 Natural bitumens and asphaltsPurified Trinidad bitumen:Purified bitumen is extracted by means of refining; it contains a mineral portion andfeatures a mass density in the neighborhood of 1,40 g/cm 3 , a penetration at 25°Cbetween 1 1/10 mm and 4 1/10 mm, and a ring and ball temperature greater than90°C. (The "soluble" bitumen exhibits a standard penetration of 3 to 12 1/10 mm anda ring and ball temperature of between 68° and 78°C).Figure 14: Example of extraction on Trinidad Lake (Venezuela)50/50 Trinidad powderThis asphalt mix is composed of 50% purified Trinidad bitumen and 50% limestonefiller.Gilsonite®Gilsonite is a natural hydrocarbon that assumes a 0/2 form, with a mass density of1,05 g/cm 3 , a standard penetration of around 0 (1/10 mm) and a ring and balltemperature greater than 150°C. The concentration extends from a few percent to10% of the dry aggregates.- 32 -


LPC Bituminous Mixtures Design Guide– General remarks –1.4.3.7 PigmentsThe pigments used in road mix techniques are mineral pigments that prove stablewhen exposed to mixing temperatures and light. The most widespread would be thefollowing metallic oxides:- red, yellow or gray iron oxides,- light yellow lead chromate,- green chrome oxide,- blue cobalt oxide,- white titanium oxide.Figure 15 : Examples of colored asphalt mixes1.5 Useful definitions and relations for type testingMost definitions are listed in the glossary found in Appendix F. Only those notionsessential to type testing have been discussed below, along with the usefulrelationships between parameters. When necessary, the European namescorresponding with the magnitudes derived below will be indicated for each definitionprovided in Appendix F.- 33 -


LPC Bituminous Mixtures Design Guide– General remarks –1.5.1 Binder contentFor the former French standards contained in the series NF P 98-130 to 98-141,binder content is TL ext , which represents the ratio of the binder mass to the dryaggregate mass, expressed as an external percentage. For this reason, the binderscontents of the examples given in the present guide are usually expressed in terms ofTL ext .TL ext= 100 ×Bitumen massDry aggregate massThe EN "product" standards included in the series EN 13108 impose the value tl int ,which is the ratio of binder mass to the total mix mass, expressed as an internalpercentage.tlintBitumen mass= 100×Dry aggregate mass + bitumen masstl int and TL ext are correlated by the following equations:TL ext100 × tl=100 − tlintinttlint100 × TL= 100 + TLextextAppendix C contains a table of equivalences between binder contents.1.5.2 Richness modulus KThe richness modulus K [Duriez, 1950] is a value proportional to the conventionalthickness of the hydrocarbon binder film coating the aggregate. K is independent ofthe density of the granular mix; it is correlated with external binder content via thefollowing equation:TL ext= K × α5Σwhere Σ is the specific surface area, expressed in square meters per kilogram,determined by the relation:100 Σ = 0,25 G + 2,3 S + 12 s + 150 f with:G the proportion of aggregate particles greater than 6,.3 mmS the proportion of aggregate particles included between 6,3 mm and0,250 mms the proportion of aggregate particles between 0,250 mm and0.,063 mmf the proportion of aggregate particles less than 0,063 mmαa correction coefficient relative to the density of aggregates- 34 -


LPC Bituminous Mixtures Design Guide– General remarks –α = 2,65 / ρ G , with ρ G being the mass density of aggregates in gramsper cubic centimetre.It is still possible to use the richness modulus, while using tl int , the equationsbeing then:tl int100 × K × α=100 +5Σ5( K × α Σ )and⎛100×tl⎜⎝100−tlK =5α Σintint⎞⎟⎠NOTE: This calculation is not applicable whenever the mix contains special fines or additives, such as fibres.1.5.3 Percentage of voids or compacity1.5.3.1 DefinitionsPercentage of voidsThe percentage of voids, or compacity, of bituminous mixtures constitutes a veryimportant parameter in the field of bituminous mixtures design. Material propertiesdepend in fact on the respective volumes of the granular skeleton, the binder(ultimately including additive volumes as well) and "free" air, called percentage ofvoids or void contentThe percentage of voids under conditions of imposed compaction – in general usingthe gyratory compactor – is the leading requirement during mix preparation. Thisrequirement matches the characteristics sought on site: texture, durability (waterresistance, fatigue resistance, rutting resistance), etc. For this reason, specimenpreparation is closely associated with percentage of voids requirements.In order to verify in situ that the expected characteristics actually correspond well withthe properties observed in the laboratory, measurement of the percentage of voidsproves to be one of the key points for verification.Volumetric compositionThe volumetric composition of a mix has been represented on the diagram inFigure 1, in conjunction with the following notations:Apparent volume VT:This amount is the total specimen volume.It is dependent upon the chosen measurement method, especially the inclusion ofspecimen surface irregularities.Void volume V m :This value represents the volume of the asphalt mix's pores and interstices.Solid volume Vr:This amount encompasses the volume of aggregate, bitumen and additives with theexception of voids, pores and interstices. It is generally expressed in percentageterms with respect to the apparent volume.- 35 -


LPC Bituminous Mixtures Design Guide– General remarks –Voids in Mineral Aggregates - VMAThis quantifies the space available within the granular mix and represents the sum ofvolumes occupied by the free bitumen and the air voids. It is also expressed as apercentage with respect to apparent volume.Bitumen volume Vb:This corresponds to the total bitumen volume within the mixture.Bitumen volume absorbed by aggregates (vba):This volume of bitumen penetrates into the aggregate pores. The absorption processdepends on aggregate porosity; it may be evaluated from the deviation between themix's actual computed mass density and actual measured mass density (seeSection 1.5.3.2).Volume of free bitumen vblThis is the bitumen volume that does not penetrate into aggregate pores.Vb = vba + vblVoids filled with bitumen VFBThis parameter, measured as a percentage, is the ratio of binder volume to voidvolume of the granular skeleton and gets incorporated into certain design methods inorder to ensure a sufficient volume of mastic (binder + filler) within the mineralskeleton.Voids in mineralaggregates VMAVoid volume Vmvolume of free bitumenvblBitumen volume absorbedby aggregates vbaBitumen volume VbApparent volume VTAggregates volume VgSolid volume VrFigure 16: Volumetric approach to developing an asphalt mix- 36 -


LPC Bituminous Mixtures Design Guide– General remarks –The distribution of voids within the mix, figure 17, allows to distinguishinterconnecting voids whose geometry enables associating two faces of a pavementor of a sample . This type of void is sought in the case of porous asphalts. Thegeometric complexity of such voids, with respect to the possibility of internal fluidflow, is called "tortuousity".Non-connecting voids open onto one face yet are blocked at the other end. Duringmeasurement of the bulk density, depending on the method employed, they may betaken into account or not, or perhaps only in part, within the volume selected for thecomputation.Occluded voids are not accessible.ConnectingVoidsNon connectingvoidsOccluded voidsFigure 17: Connecting, non-connecting and occluded voidsMaximum densityThe maximum density may be directly determined on the mix according toStandard EN 12697-5 using Method A with water, in which case it getsdenoted MVR.It may be calculated from component mass densities obtained by means of variousmethods (water, solvent, paraffin oil) and would then be denoted MVRc, based onthe following formulas:MVRc =Aggregate mass + Bitumen massVg + VbCase of an external binder content TL ext :MVRc =%Gρ1g1100+TLext%G2%G+ + .... +ρg2 ρgnnTL+ρbextCase of an internal binder content tl int :MVRc =%Gρ1g1%G+ρ2g 2100%G+ .... +ρgnntlint+ρb- 37 -


LPC Bituminous Mixtures Design Guide– General remarks –where %G i are the mass percentages of granular fractions and ρ gi their respectivemass densities. It should be pointed out that in the formula corresponding to the caseTL ext , %G 1 +%G 2 +…+ %G n = 100, whereas in the formula corresponding to the casetl int , %G 1 +%G 2 +…+ %G n = 100 - tl int .ρ b is the mass density of bitumen.The MVRc value depends on the method chosen for measuring the mass density ofcomponents and in particular that of aggregates. If aggregate mass densities aremeasured by methods using fluids, whose viscosity enables penetrating into grainporosities (water, solvent), the MVRc value may be overestimated. This method isalso employed to determine the quantity of bitumen absorbed. When aggregate massdensities are determined using a paraffin oil whose viscosity lies near that of thebitumen, the calculation method and direct measurement yield similar results.Bulk densityBulk density is derived from the ratio of the sample mass to its apparent volume. Thisapparent volume may be determined by means of geometric measurement (MVA) orhydrostatic weighing, with or without paraffin EN 12697-6) depending on the materialvoids content (MVa). The bulk density can also be assessed using a Gamma benchmeasurement: MVaγ (EN 12697-7).Percentage of voids and compacityThe compacity and percentage of voids are derived from both actual mass densitymeasurements MVR and bulk density measurements MVA (MVa or MVaγ), using thefollowing relations:C% = 100 x (MVa or MVA or MVaγ) / MVRv% = 100 [1 - (MVa or MVA or MVaγ) / MVR]1.5.3.2 Relations between parametersVoids content and compacityCompacity C% and the percentage of voids v% are correlated by the followingequation:100 = C% + v%- 38 -


LPC Bituminous Mixtures Design Guide– General remarks –Volume of voids in mineral aggregate VMACase of an external binder content TL ext :VMA% (or air voids and free bitumen) =⎛ 100 × (MVR × ( 100 − v )) ⎞⎜100−⎟⎝ ρg(100 + TLext) ⎠⎛ ( 100 − v ) × MVRρg− ⎜⎝ 100VMA% =ρgCase of an internal binder content tl int :tlintVMA%= v + × MVAρb⎞⎟ ×⎠Volume of bitumen absorbed by aggregates (vba)⎛ TLext⎜1−⎝ 100 −TL⎛⎛1 ⎞ ⎛ 1 ⎞⎞vba = 100 × MVa ⎜⎜⎟ − ⎜ ⎟⎟⎝⎝MVR ⎠ ⎝ MVRc ⎠⎠MVRc is the mix's computed MVR.If the mass density measurement of aggregates is performed according to the Frenchstandard P 18-559 (i.e. measured using paraffin oil), the volume of bitumen absorbedwould be zero, hence vba = 0.Percentage of voids filled with bitumen (VFB)Vb%VFB = 100VMA%where Vb is the volume of binder expressed as a percentage.Case of an external binder content TL ext :TLext× MVR × ( 100 − v )Vb% =× 100( 100 + TL ) × ρbCase of an internal binder content tl int :extext⎟ ⎞⎠VFB =tlintMVA×ρbVMA× 100- 39 -


LPC Bituminous Mixtures Design Guide– General remarks –with:tl intTL extMVAρbvρgtl × MVAintρbVFB =v +⎛⎞⎜tl× MVAint ⎟⎝ ρb⎠"internal" binder content"external" binder contentbulk density of the specimendensity of the bitumenpercentage of voidsdensity of the mineral skeleton- 40 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -2 TYPE TESTING OF BITUMINOUS MIXTURESOn the basis of a set of components (aggregates, fines, bituminous binders, mineralor organic additives), deemed representative of applicable materials, a series oflaboratory tests is conducted to describe the behavior of a bituminous mixture. Thespecific tests have been chosen depending on the type testing level (from 1 to 4, thelevel 0 doesn’t include tests), required by the contract, potentially along withadditional tests. This type testing level typically depends upon: the type of mixture,the position of the bituminous mixture layer in the pavement, its thickness, projectedtraffic levels, any special loadings (road ramps, interchanges, local temperature), theparticular objective for applying this layer, the kinds of layers positioned beneath, andthe scope of the given road-building works.A test protocol containing a sensitivity study may be required in order to verify thatdespite compositional variations in the mixture, the targeted characteristics willindeed be obtained.Type testing protocols have been stipulated in normative prescriptions included informer French product standard series NF P 98-130 through NF P 98-141, as well asin the general standard NF P 98-150-1 Bituminous mixtures, constituents, typetesting, manufacturing, application and control. Most of these prescriptions arecompatible with the current European product standards (EN 13108 – 1 to 7 and EN13108-20 type testing) and have been included in the national foreword of the Frenchversion. In order to benefit from the experience gained on French bituminousmixtures types, taking into account the EN standardization, the designation of thebituminous mixtures types addressed in this Guide includes the EN designationfollowed by the French one. The most used products are listed and described inappendix F. Appendix E provides a summary table listing all specifications anddesignations based on the French experience, by type of mixture. For example forasphalt concretes AC according to EN 13108-1 (EB in the French version of EN), thefollowing materials are addressed:• AC-BBSG (Béton Bitumineux Semi-Grenu)• AC-BBME (Béton Bitumineux à Module Élevé)• AC-BBS (Béton Bitumineux pour chaussées Souples à faible trafic)• AC-BBM (Béton Bitumineux Mince)• AC-BBA (Béton Bitumineux Aéronautique)• AC-GB (Grave-Bitume), Empirical and Fundamental• AC-EME (Enrobé à Module Élevé).And in the same way, for the other types of materials:• BBTM (Béton Bitumineux Très Mince)7The base series of the sieve is composed of the following elements (in mm): 0,063; 0,125; 0,250;0,500; 1; 2; 4; 8; 16; 31,5.- 41 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -• PA-BBDr (Porous Asphalt – Béton Bitumineux Drainant)Note that some of the prescriptions used to be normative in the former Frenchstandardization system. They now become informative as a French choice in the ENstandards.The objective of this part of the guide is to compile the set of prescriptions, includingthe informative French choice, relative to: the components used, mix composition,test specimen preparation, and key material performance parameters.The used references are the following:- Aggregates according EN 13043 and Standard XP P18-545, which is theFrench application guide for EN 13043,- Reclaimed asphalt according EN 13108-8,- Binders according EN 12591, EN 13924 and EN 14023,- Bituminous mixtures, according EN 13108-2, -5, -7,- Type testing, according EN 13108-20,- Conditions concerning specimen preparation according test standards fromseries EN 12697.At the end of this chapter, the requirements of European standards for initial typetesting are presented in the form of summary tables.2.1 Prescription relative to mix componentsFor some properties of the product undergoing qualification, due to the absence of areliable enough method for identifying properties within the mixture, componentbasedprescriptions are imposed. Such is especially the case for durability propertieswhen exposed to traffic, during the fabrication and implementation phases, as well asfor surface characteristics.2.1.1 Specifications regarding added fillersThe specifications issued on fillers have been set forth in Standard EN 13043.Among them, the following merit attention:- Particle size distribution: lower limit and maximum range with the 0,125 mmand 0,063 mm sieves- Harmful fines MBF (methylene blue test [EN 933-9])- Voids of dry compacted filler V (Rigden void index [ EN 1097-4])- Stiffening power Delta Ring and Ball ∆ R&B [ EN 13179-1]- Additional prescription focusing on the Blaine specific surface [ EN 196-6],meant to characterizing consistency of filler production.The two typical categories of fillers for such applications have been summarized inTable 1 below.- 42 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -Table 1 – Typical filler characteristics for asphalt mixturesParticle size criteriaSieve size (mm)HarmfulfinesStiffening properties2 0,125 0,063Passing Passing Range Passing RangeMBF, ing/kg(Rigden)V, in%∆ R&B , in°C≥ 100 85 to 100 ≤ 10 ≥ 70 ≤ 10 ≤ 10MB F 1028 to 38V 28/388 to 16denoted ∆ R&B 8/162.1.2 Specifications regarding fillers contained in the mixtureProduct standards also contain specifications relative to either the fines from fineaggregate or mixed fillers (i.e. fines taken from fine aggregate and added fillers). Thefines from fine aggregate or mixed fillers are extracted by means of dry sieving withthe 0,125 mm sieve. These specifications have been recalled in Table 2. In the mixesproduced at the plant, the fines for the most part stem not only from a fine aggregatewith filler, but also from fine-particle aggregate at the surface of coarser aggregatesand the fines produced by means of aggregate attrition during both the drying andmixing phases. Consequently, the fines from crushed aggregate must comply withStandard EN 13043, whose specifications are included in Table 2.An additional restriction pertains to the use of filler containing calcium hydroxide,which content must not exceed 1% within the mixture.Table 2 – Specification on fines from fine aggregate or all-in aggregate or (in their absence)from mixed fillersCharacteristicMBFin g / 1000g(Rigden)Vin %∆ R&Bin °CSpecificationEN 13043≤ 10MB F 1028 to 38V 28/388 to 16∆ R&B 8/162.1.3 Specifications regarding fine aggregates or all-in aggregate (0/4, 0/6)The fine aggregates used herein are either 0/2 (as defined in Standard EN 13043),or0/4 all-in aggregate, for the majority of asphalt mixes. For AC-GB (Graves-bitume -dense asphalt concrete for base course), high modulus asphalt concrete (AC-EME)and “soft” asphalt concretes used on flexible pavements with low traffic loads (AC-BBS), the 0/6 fraction is acceptable.The fine aggregates 0/2 are sorted into category G F 85 according to Standard EN13043. They display 100% passing at the 4 mm sieve and between 85% and 99% atthe 2 mm sieve. This set of characteristics corresponds to the code "a" defined inStandard XP P18-545, which is the French application guide for EN 13043.- 43 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -The 0/4 and 0/6 all-in aggregates are of category G A 85 (passing 100% at 2D, 98-100% at 1,4D, and 85-99% at D).The tolerances applied to the particle size distribution of both fine and coarseaggregate must respect the specifications associated with category G TC 10 (±5% at D,±10% at D/2, ±3% at 0,063 mm).The harmfulness of fine and coarse aggregate must be either MB F 10 (as measuredon the fines from fine aggregate) or MB 2 (as measured on the 0/2 particle sizes)which is considered more severe than MB F10.The fines content from fine aggregate generally lies between 12% and 22%. Fineaggregates from category f 16 or f 22 can also be used, but in all cases, the finescontent from fine aggregate must be specified through a declared value.The minimum angularity of fine aggregates (EN 933-6) is determined when themixture is intended for surface courses. In general, this would apply to the categoriesE CS 35 or 38, except in the case of “soft “ asphalt concrete AC-BBS (asphalt concreteused on flexible pavements with low traffic loads), for which E CS 30 is accepted.For the other asphalt mixtures (used for the binder or base courses), angularity is notspecified in the case where a wheel tracking test has been called for in the typetesting protocol.Limiting the inclusion rate to just 10% of fine aggregate with round particles (declaredE CS < 30) is accepted for the asphalt concrete for surface and binder course ( “BétonBitumineux Semi Grenu” AC-BBSG), asphalt concrete for airfields (Béton Bitumineuxaéronautique – AC-BBA), “soft” asphalt concrete (Béton Bitumineux Souple AC-BBS)and High modulus asphalt concrete for surface and binder course (Béton Bitumineuxà module élevé – AC-BBME) categories.For asphalt concretes, a maximum value of fine aggregate friability (EN 932-3) is setat 40 for a 0/4 and at 45 for a 0/2. These specifications are not included any more inthe product standards, however, they may be relevant and then can be verified.2.1.4 Specifications regarding coarse aggregates2.1.4.1 Physical requirements (Mechanical strength) and productioncharacteristicsBoth the minimum mechanical strength values and minimum productioncharacteristics of coarse aggregates depend upon the position of the layer for whichthe mix is being designed as well as its thickness for surface courses.Production characteristics deal with grading, shape and fines content.Concerning the grading characteristics, the category G C 85/20 [passing to D sievebetween 85 % and 99 %, passing to d sieve between 0 % and 20 %, 100 % to 2 Dsieve, 0 % to 5 % to d/2 sieve] is generally retained. For gap-graded mixtures,category G C 85/15 may be necessary [passing to d sieve between 0 % and 15 %,instead of 20 % and for single size coarse aggregate D/d, where D/d < 2, which is thecase for gap-graded mixtures used in surface course, passing to D sieve between 90% and 99 %, 100 % to 2 D sieve, 0 % to 5 % to d/2 sieve]- 44 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -The percentage passing at mid-size sieve [D/1,4], shall be between 25 % and 80 %for base course materials, and between 20% and 70% for binder and surface coursematerials, with in both cases, a tolerance on the typical grading of ± 15 %, declaredby the producer, that means categories respectively G 25/15 and G 20/15 .The shape of coarse aggregate is determined in terms of the flakiness index FI. FI 25is the generally retained category. For very thin layers intended mixtures, categoryFI 20 may be necessary.The fines content of coarse aggregate is measured by the percentage of passing at0,063 mm sieve. Category f 1 is used [≤ 1 % at 0,063 mm sieve], for common usesand category f 0,5 for very thin layer intended materials.An overview of these characteristics is given in table 3.- 45 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -Table 3 – Indicative minimum characteristics of coarse aggregates :Mechanical strength and production characteristicsThe minimum values, as indicated in bold characters, extracted from Standard EN 13043,correspond to classifications either less than or equal to the minima transposed from the formerFrench aggregate standards. The italic values correspond to the French application of aggregatestandards as described in XP P 18-545.Type of useLower base layerUpper Base layerMechanical strengthEN 13043XP P 18-545LA 40 M DE 35LA 40 M DE35(1)LA 30 M DE 25LA 30 M DE 25(1)Production characteristicsG C 85/20G 25/15FI 25 f 1G C 85/20G 25/15FI 25 f 1Thick binder layer(≥ 5cm)Thin binder layer (AC-BBM)Thick surface course andlightweight airfield pavementsThin surface course (BBTMand Porous Asphalt PA-BBDr)and heavy airfield pavementsLA 30 M DE 25LA 30 M DE 25(1)G C 85/20G 20/15FI 25 f 1LA 25 M DE 20G C 85/20LA 25 M DE 20 (1) G 20/15FI 25 f 1LA 25 M DE 20PSV M DE 50LA 25 M DE 20(1)LA 20 MDE15PSV 50(2)LA 20 M DE15(1)G C 85/20G 20/15FI 25 f 1G C 85/15 (gap-graded grading)G C 85/20G 20/15FI 20 f 0,5(1)With any potential application, when justified and given an explicit justification within the materials contract documents, amaximum compensation of 5 points between the LA and MDE characteristics (see XP P 18-545). For example:⎯ an aggregate with LA = 25 is deemed compliant with [LA 20 , M DE 15] if it exhibits an MDE value of 10⎯ an aggregate with M DE = 20 is deemed compliant with [LA 20 , M DE 15] if it exhibits an LA value of 15⎯ an aggregate with M DE = 18 is deemed compliant with [LA 20 , M DE 15] if it exhibits an LA value of 17(2)For a number of unique points, it becomes necessary to predict the PSV 53 (declared) value, or even the PSV 56 value.2.1.4.2 Particle size distributionFor coarse aggregates, the usual grading fractions are: 2/4, 2/6, 4/6, 4/10, 6/10and 10/14.For mixes intended in applications as road base, the fractions 2/10, 6/14, 6/20, 10/20and 14/20 may also be used.The possible D values for each type of mixture are displayed in Table 4.- 46 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -Standard EN 13043 imposes using the base series + series 2 sieve or the baseseries + series 1 sieve. It is common practice to opt for the base series + series 2sieve.Table 4 – Accepted values of D vs. type of mixtureAsphalt mixAsphalt concrete for surface and binder course(AC-BBSG)High modulus asphalt concrete for surface andbinder course (AC-BBME)Asphalt concrete for surface and binder coursefor airfield (AC-BBA)Thin layer asphalt concrete A or B type(AC-BBM type A or B)Graves-bitume (Asphalt concrete for base)(AC-GB)High modulus asphalt concrete for base course(AC-EME)Thin layer asphalt concrete C type( AC-BBM type C)Very thin layer asphalt concrete (BBTM), Porousasphalt (PA-BBDr)D, expressed in mm10 - 1414 - 20 (2)10 - 14 - 20 (2)106 - 10 (1)(1)(2)It is possible to use the 8-mm sieve (European standard).It is possible to use the 16-mm sieve (European standard).The type A thin layer asphalt concretes (AC-BBM type A) are characterized by adiscontinuity between 2 and 6 mm, while the type B (AC-BBM type B) arecharacterized by a discontinuity between 4 and 6 mm. The type C (AC-BBM type C)mix designs are of a continuous grading.2.1.4.3 AngularityThe angularity of coarse aggregates exerts a sizable impact on the surface coursewith respect to texture, which is why this characteristic must always be taken intoaccount for mixes designed with this purpose.The angularity of coarse aggregates is measured in accordance with StandardEN 933-5 guidelines. The aggregates derived from crushed rock are considered to liein category C 100/0 .Coarse aggregates from alluvial deposit extraction for use on surface courses mustbe of category C 95/1 . For some “soft” asphalt concretes types (AC-BBS) submitted tolow traffic levels, coarse aggregates of category C 50/10 could also be employed.2.1.5 Specifications regarding additivesNo distinct specification has been incorporated into the standards.- 47 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -The term additives encompasses adhesion agents – for which the potentialdegradation when exposed to temperature has been indicated [NF P 98-150-1] – aswell as organic and mineral additives intended to modify the physical and mechanicalcharacteristics of asphalt mixes. It has to be pointed out that according to EN 13108series, only constituent materials with established suitability shall be used. Theestablishment of suitability shall result from one or more of the following: EuropeanStandards, European Technical Approval (ETA), specifications for materials basedon demonstrable history of satisfactory use in asphalt. Evidence shall be provided ontheir suitability. This evidence may be based on research combined with evidencefrom practice.In the European asphalt industry, it is common practice to use additives like inorganicor organic fibers, pigments, waxes, etc, which are not covered by European standardor ETA. The European product standards allow the use of those materials.It should be pointed out that the content of an adhesion agent is equal to the mass ofthe agent as a ratio of binder mass, expressed as an external percentage or perthousand.The content of additives (other than adhesion agents) may be expressedas the additive mass as a ratio of dry aggregate mass, expressed as an externalpercentage or as a ratio of mixture mass, expressed as an internal percentage.Additives are to be incorporated at the time of the mixing operation.2.1.6 Specifications regarding bindersFor all asphalt mixes, the choice lies between paving grade bitumen, in compliancewith EN 12591, polymer-modified bitumen and special bitumen, with the objectivebeing to derive the prescribed level of mix performance.In the case of prescribed polymer-modified bitumen performance, no codifiedspecification is in fact available. The standard EN 14023 is confined to just a singleclassification.Nevertheless two types of polymer-modified bitumen are usually specified accordingto a minimum plasticity interval, defined by difference between the softening pointand Fraass temperature, and the level of maximum Fraass temperature.The first criterion shows degree of modification, high degree for class 4 > 75°C andlow degree for class 6 > 65°C. The second criterion depends on local climate conditions, forexample class 5 (Fraass temperature < -10°C) or class 7 (Fraass temperature < -15°C).With respect to hard grade bitumen, these specifications have been included in thestandard EN 13924. The French recommended binders in the National annex are10/20 with a ring and ball range from 60°C to 76°C and 15/25 with a ring and ballrange from 55°C to 71°C. The supplier shall declare a reduced softening point of ±5°C around the central point. The resistance to hardening using RTFOT test is class2 (mass variation < 0,5%, increase of softening point < 8°C, remaining penetrability >55%).In the case of recycled mixes and for recycling rates over 10% for surface coursesand over 20% for binder courses and bases , it has been stipulated in EN 13108series that the added binder is a pure bitumen, which makes the level of penetrationP or the softening point T R&B resulting from the combined binder well adapted to thedesired end use. The mixture rules can then be applied to penetration as follows:- 48 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -lg(P) = a lg (P1) +b lg (P2)where a and b are the respective proportions of binders, P1 being the penetration ofthe binder recovered from the reclaimed asphalt and P2 the penetration of the addedbinder.T R&Bmix = a T R&B1 +b T R&B2where a and b are the respective proportions of binders, T R&B1 being the softeningpoint of the binder recovered from the reclaimed asphalt and T R&B2 the softeningpoint of the added binder.When natural asphalt is added, it shall comply with Annex B of EN 13108-4requirements. Two categories are defined: High ash and Low ash content. For thefirst category, the penetration at 25°C, shall be between 0 and 4 1/10 mm, thesoftening point between 93 and 99 °C, the solubility between 52 and 55%, the ashcontent between 35 and 39% by mass and the density between 1,39 and 1,42 g/ml.For the second category, the penetration at 25°C, shall be between 0 and 1 1/10 mm,the softening point between 160 and 182 °C, the solubility greater than 95%, the ashcontent between 0 and 2% by mass and the density between 1,01 and 1,09 g/ml.2.1.7 Specifications regarding reclaimed asphaltThese specifications are described in EN 13108-8.The reclaimed asphalt is designated by the abbreviation RA preceded by the asphaltparticle size designation U and followed by the aggregate size designation d/D inmm. U is the smallest sieve size in mm trough which 100% of the asphalt particlespass. For RA, d will almost invariably be 0. D is the larger of:- the sieve M/1,4, where M is the smallest sieve with 100% passing,- the smallest sieve with 85% passing.The reclaimed asphalts are classified in terms of foreign matter content. Usually thecategory used is F1 corresponding to materials containing less than 1% of group 1foreign matters (cement concrete, bricks, cement mortar, metal) and less than 0,1 %of group 2 foreign matters (synthetic materials, wood, plastics).The reclaimed asphalt capable of being reused exhibit an apparent U (particle size ofreclaimed asphalt) value of less than or equal to 35 mm.The upper sieve size D of the aggregate in reclaimed asphalt shall not exceed theupper sieve size D of the mixture to be produced. The aggregate properties of thereclaimed asphalt shall fulfill the requirements for the aggregate for the mixture(history may be accepted).When using more than 10 % by mass of the total mixture of reclaimed asphalt forsurface courses or more than 20 % for other courses, in which only paving gradebitumen has been used, and when the binder added is a paving grade and the gradeof the bitumen of the mixture is required, the binder shall conform to the followingrequirement:Penetration or softening point of the binder in the resulting mixture, calculated fromthe penetrations or the softening points of the added and the recovered binder fromreclaimed asphalt shall meet the penetration or softening point requirements of theselected grade. Either the penetration or the softening point has to be considered.- 49 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -The calculation is described in Annex A of each standard from EN 13108 series andin clause 2.1.6.When the feedstock contains mainly reclaimed asphalt with paving grade bitumen,reclaimed asphalt are categorized as P 15 , if the binder of each of the sample is atleast 10 1/10 mm and the mean penetration of all samples is at least 15 1/10 mm or itis categorized as S 70 if softening point of each of the samples is not greater than77°C and the mean softening point of all of the samples is not greater than 70°C. Forother reclaimed asphalt category Pdec or Sdec means the mean penetration or themean softening point of all samples.It would be beneficial to distinguish the reclaimed asphalts of various sources fromthose that have undergone a generally complete identification (either by testing or byhistory) with respect to binder content and homogeneity, as well as the residualproperties of the recovered binder and aggregate characteristics.It is acknowledged that reclaimed asphalts from the first category may be used at arate of 10% in mixes not destined for surface courses.Reclaimed asphalts belonging to other categories may be recycled as wearingcourse components and, depending on the specific circumstances, at higherrecycling rates.For both porous asphalts, PA, and very thin layer asphalt concretes, BBTM, however,the inclusion of reclaimed asphalts is not recommended. For thin asphalt concretesof the A or B type, as a default precaution reclaimed asphalts are not authorized.The French standard application guide includes a table about the reuse rate ofreclaimed asphalt versus the use and the degree of knowledge of the material, thistable is coming from the former French Standard XP P98-135 Reclaimed asphalt.The reclaimed asphalt characteristics to be identified for reuse purposes have beensummarized in Table 5 below:- 50 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -Table 5 – Reclaimed asphalt characteristics vs. reuse rateUse in the pavementType of layer Reuse rate (%)Surface course 0 010 subject(1) 30 40toBinder layer 10 20 30 40Base course 10 20 30 40Binder content Range Unspecified ≤ 2% ≤ 1%Information on reclaimed asphalt componentsAsphaltbinderAggregatesResidualcharacteristics(penetration orSoftening point)Particle sizedistributionIntrinsiccharacteristicsPenetrability1/10 mm≥ 5 ≥ 5Penetrationrange – ≤ 15R&B °C ≤ 77 ≤ 77R&B rangePassing at DRangeRange of2-mmpassingRange of0,063 mmpassingCategoryUnspecifiedUnspecifiedUnspecified– ≤ 880 - 99≤ 1585 - 99≤ 10≤ 20 ≤ 15≤ 6 ≤ 4For exampleLA 20 ,M DE 20Angularity – C 90/1(1)If the average external binder content of the reclaimed asphalt exceeds 5,5%, it is then considered that the mix is anasphalt concrete whose aggregates have been selected on the basis of minimum criteria in the vicinity of the criteriasought for the recycled material. Nevertheless no limestone aggregate should be used as surface course.2.2 Specifications regarding mixture composition2.2.1 GradingThe particle size distribution curve is not specified in the French standard.Nevertheless overall limits of target composition are required (grading envelope) for0,063 mm, 2 mm, D and 1,4 D sieves. Pertinent specifications have been listed inTable 6.- 51 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -Table 6 – Overall limits of target compositionAsphalt mix0,063 mm sievepassingin %2-mm sievepassing,in %Din %1,4 Din %AC10 2,0 to 12,0 10 to 60 90 to 100 100AC14 0,0 to 12,0AC20 0,0 to 11,010 to 5010 to 60 forairfields10 to 5010 to 60 forairfields90 to 100 10090 to 100 100BBTM6A 7,0 to 9,0 (11) 25 to 35 90 to 100 100BBTM6B 4,0 to 6,0 15 to 25 90 to 100 100BBTM10A 7,0 to 9,0 25 to 35 90 to 100 100BBTM10B 4,0 to 6,0 15 to 25 90 to 100 100PA-BBDr 2,0 to 10,0 5 to 25 90 to 100 1002.2.2 Binder content and Richness ModulusIn the former French system, the binder content was based on the concept of“Richness Modulus”, whose approach is close to the thickness of the bitumen foil andwhich makes the requirement independent from the grading curve of the mixture.In order to conform to EN 13108 series which doesn’t deal with this concept, therequirements have been translated in “binder content”. In the case of empiricalapproach, a B min value is given for each type pf material, in the case of fundamentalapproach , the minimum binder content is fixed at 3,0%.Nevertheless, to keep for reference this concept, the richness modulus is mentionedin parallel with the minimum binder content in table 7.- 52 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -Table 7 – Minimum Binder content and richness modulus valuesAsphalt mixMinimum bindercontent %Empirical FundamentalMinimum richnessmodulusKAC10-BBSG B min5,2 3,0% 3,4AC14-BBSG B min5,03,0%3,2AC10-BBA C (Continuous) B min5,43,0%3,6AC14-BBA C (Continuous) B min5,23,0%3,5AC10-BBA D (Discontinuous) B min5,23,0%3,4AC14-BBA D (Discontinuous) B min5,03,0%3,2AC10-BBM B min5,0-3,3AC14-BBM B min5,0-3,2PA6-BBDr class 1 B min4,0-3,4PA6-BBDr class 2 B min4,0-3,2PA10-BBDr class 1 B min4,0-3,3PA10-BBDr class2 B min4,0-3,1BBTM6 B min5,0-3,5BBTM10 B min5,0-3,4AC-GB class 1 1 (B min3,4 ) - --AC-GB class 2AC-GB class 3B min3,8B min4,23,0%2,53,0%2,8AC-GB class 4 2 - 3,0%2,9AC-EME class 1 2 - 3,0%2,5AC-EME class 2 2 - 3,0%3,4AC10-BBME 2 - 3,0%3,5AC14-BBME 2 - 3,0%3,3Note 1: GB1 was not considered in the last version of French Standardization.Note 2: Due to the fundamental approach, the minimum binder content is not specified. 3% is a bottom rate of the EN 13108-1for all types of asphalt concretes described by the fundamental approach.2.3 Preparation of test specimens2.3.1 Density measurementsThe maximum density ρ mv (MVR in French documents) is measured directly on themixture (hot-mixing of 1,5 kg, in compliance with the formula) using the "A" method"with water" described in EN 12697-5 (average of 3 replicas). This method is thereference method in EN 13108-20 for the void content determination of thespecimens and for the gyratory compaction test.This method offers the advantage of being implemented on the total mixture, whichallows reducing the number of tests to be performed, in comparison with the- 53 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -calculation method based on the maximum density of each granular fraction. Whenrefining the mix design, in the aim of varying component proportions, the method maybe practiced on each one of the granular fractions, after mixing with a known bitumenconcentration. The maximum density ρ g of the granular fraction, mixed in at abitumen content of TL ext or tl int , is thus given by the following relations:MVRMVR(100− tlint)ρg=ρg=TL ⎛ ⎞+extMVRtlint1⎜1−⎟100 − MVR100 ⎝ ρb⎠ρbwhere ρ b is the maximum density of the binder.The MVR derived according to this approach serves as a basis not only forcalculating the void percentages of specimens submitted to evaluation within thescope of this type testing, but also for conducting in situ measurements.In the former French system, the maximum density of aggregates was measured inaccordance with the standard P 18-559 using paraffin oil featuring a viscosity close tothat of bitumen during the mixing operation. The maximum density MVR of themixture could then be calculated by applying the following formula (binder content is“out” of the mixture):MVR =%Gρ1g1100+TLext%G2%G+ + .... +ρg2 ρngnTL+ρbwhere %G iare the granular fraction percentages and ρ itheir respective maximumdensities.This method, which was mandated in the "product" standards, makes it possible toovercome the notion of absorbed bitumen for aggregates displaying a certain amountof porosity. Moreover, by making reference to a single method for determining MVR,the subsequent measurements of void percentage can be more easily compared.A joint USIRF (French Road Industry organization) / RST (French state Laboratories)working group has demonstrated that a very strong correlation was found betweenMVR measured directly on the mixture with water and that calculated using theparaffin oil-based method for each of the garnular fractions.2.3.2 Procedure for reheating and incorporating mix reclaimed asphaltsThe European standard addresses the incorporation of reclaimed asphalts; oncepulverized, the reclaimed asphalts are weighed to within 0,1%, at the prescribed ratelevels:⎯Case of reclaimed asphalts reheated prior to incorporation at the plant: they arereheated up to the recommended temperature ± 5°C, by means of a hopperfitted with ventilation, and then placed in an oven at the designated preparationtemperature for 2,5 ± 0,5 hours.The hopper must be periodically shaken inorder to avoid excess pressure buildup.ext- 54 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -⎯ Case of reclaimed asphalts not reheated prior to incorporation at the plant: theyare reheated to 110 ± 5°C, by means of a ventilated oven, for 2,5 ± 0,5 hours. Itis possible to overheat the unmixed aggregate compared to the standardtemperature vs. reclaimed asphalt concentration.When using paving-grade bitumen, mixing times get increased by 1 min.2.3.3 MixingThe mixtures are produced in accordance with EN 12697-35. In the EN standard, theadded filler is included either with the aggregates or after introducing the bitumen. Itis customary to opt for the former.As opposed to the specifications listed in the former French standard, the Europeanstandard does not address the overheating of aggregates if the mixer has not beenequipped with a thermo-regulated tank.2.3.4 Compaction of test specimensFor water resistance tests, specimens are either compacted using the gyratorycompactor or in the form of cored samples extracted from plates produced using theslab compactor. However, when using EN 12697-12, part B (Duriez test), it isnecessary to compact specimens using double static compression described in partB, in order to compare the obtained results with the former NF P 98251-1 (Durieztest).For mechanical tests, the plates are also generated with the slab compactor, asspecified in EN 12697-33, at a targeted level of compacity. The use of a plate orplank at the completion of compaction, in order to improve the state of the platesurface, is not allowed since the impact on the wheel tracking test result has alreadybeen shown.2.3.5 Test specimen sawing and bondingCylindrical or trapezoidal test specimens are sawn and bonded as prescribed in thestandard NF P 98-250-3 guidelines. This point has not been addressed in theEuropean standards.2.3.6 Test specimen conservationFor the ITSR water resistance test, specimens must undergo a minimum storage of16 hours between specimen production and the beginning of conservation.For a wheel tracking test, it is necessary to set aside at least 2 days between the endof compaction and preparation on the rutting tester (EN 12697-22).For a fatigue or stiffness test, the time lag between coring or sawing and test initiationamounts to between 2 weeks and 2 months.- 55 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -2.3.7 Test specimen void percentageThe test specimens intended for use in either wheel tracking or mechanical tests(stiffness or fatigue) must satisfy a number of specifications concerning voidpercentages.The void percentage may be determined on the slab using a gamma bench, as setforth in standard EN 12697-7 through a three-level operation. Should such a set-upnot be available, void percentages are to be measured using the geometric methodeither on the slab for wheel-tracking tests or on the samples for stiffness or fatigue.Common values are listed in Table 8 below.Table 8 – Test specimen characteristicsWheel tracking tests(large device)Slabthickness(mm)Void percentage(%)Fatigue / stiffness modulusSlabthickness(mm)Void percentage(%)AC-BBSG and AC-BBME 100 5 to 8 120 5 to 8AC-BBM class A 50 7 to 10AC-BBA (except AC10-BBA D) 100 4 to 7 120 4 to 7AC10-BBA D 50 4 to 7 120 4 to 7AC-BBM class B or C 50 8 to 11AC-GB class 2 100 8 to 11 120 7 to 10AC-GB class 3 100 7 to 10 120 7 to 10AC-GB class 4 100 5 to 8 120 5 to 8AC-EME class 1 100 7 to 10 120 7 to 10AC-EME class 2 100 3 to 6 120 3 to 6BBTM10 50 9 to 16BBTM6 50 16 to 22The bulk density of the twospecimens used to measure therut depth shall not deviate bymore than ± 1% of the meanbulk density2.4 Execution of type testingDepending upon the intended use, the type of asphalt mix and loadings,requirements may differ. For this reason, type testing is divided into several levelsextending from 0 to 4, and complemented for certain materials or uses by additionaltests.2.4.1 Choice of test typing levelLevel 0, which has been introduced into the French foreword of the standards andalso in NF 98-150-1 corresponds to a description of the mixture according to grading- 56 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -and binder content, that means without any further test. It is used for mixturesintended to non-trafficked areas.The other various testing levels vary from the simplest (level 1) to the most thorough(level 4), with the higher levels always encompassing the requirements addressed inthe lower levels.A description of contents for each level along with the reasons behind thecorresponding choice will be provided in the following sections 2.4.2 through 2.4.5.The level 0, without test is not described.According the definitions of EN 13108-1, level 0, level 1 and level 2 are relevant ofthe general + empirical approach and level 3 and level 4 of the general +fundamental one.Level 4Level Niveau4Level Niveau3Level 2NiveauLevel 1NiveauLevel 0FatiguFatigueStiffness ModulmodulusOrniérage WheeltrackingGyratory compactor :Water resistanceGeneral +FundamentalGeneral +EmpiricalFigure 18: Summary diagram of the various type testing levels2.4.2 Level 1The mixture must be able to satisfy a full range of void percentages for use in theGyratory Compactor test (see Section 1.3.1) as well as the water resistancethreshold (Section 1.3.2).- 57 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -Except for non trafficked areas, this level would be common to all testing protocols. Inthe case of applications at low loading rates, level 1 may be sufficient without theneed for any further test. The water-sensitivity is measured according EN12697-12,method B in compression.Remark: For some materials, a void percentage requirement at 10 gyrations for theGyratory Compactor test needs to be met. This requirement has been addressed inthe European standards, yet merely from the standpoint of an "empirical"specification with respect to wheel tracking resistance. It is then not allowed tospecify, at the same time, both rutting tester results and the void percentage after 10gyrations as it is considered as an over-specification.Table 9 – Specifications relative to the void percentageType of mixGyratory Compactor specificationsafter n gyrationsNumberofgyrations(n)Void percentage(%)Specification after10 gyrations (%)AC10-BBSG 60 5 to 10 V min5 - V max10AC14-BBSG 80 4 to 9 V min4 - V max9≥ 11V10G min11AC10-BBME 60 5 to 10 V min5 - V max10AC14-BBME 80 4 to 9 V min4 - V max9BBTM6 class A 12 to 20 V min12 - V max20BBTM6B 21 to 25 V min12 - V max2525BBTM10A 10 to 18 V min10 - V max18BBTM10B19 to 25 V min19 - V max25AC-BBM class A 6 to 11 V min6 - V max11AC-BBM class B 40 7 to 12 V min7 - V max12AC-BBM class C8 to 13 V min8 - V max13≥ 11_≥ 11V10G min11V10G min11PA-BBDr class 1PA-BBDr class 240 20 to 25 V min20 - V max25200 > 15 V min1540 25 to 30 V min25 - V max30200 > 20 V min20_AC10-EME class 1 < 10 V max1080AC10-EME class 2< 6 V max6AC14-EME class 1 < 10 V max10100AC14-EME class 2< 6 V max6_AC20-EME class 2 120 < 6 V max6AC14-GB class 2 < 11 V max11AC14-GB class 3 100 < 10 V max10AC14-GB class 4< 9 V max9>14 V10G min14- 58 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -Type of mixGyratory Compactor specificationsafter n gyrationsNumberofgyrations(n)Void percentage(%)Specification after10 gyrations (%)AC20-GB class 2 < 11 V max11AC20-GB class 3 120 < 10 V max10AC20-GB class 4< 9 V max9AC10-BBA C 60AC14-BBA C 80Surface:3 - 7Binder:4 - 8Surface:3 - 7Binder:4 - 8V min3 - V max7 > 10 V10G min10V min4 - V max8 > 11 V10G min11V min3 - V max7 >10 V10G min10V min4 - V max8 >11 V10G min11AC10-BBA D 40 5 to 9 V min5 - V max9 > 9 V10G min9AC14-BBA D 60 5 to 9 V min5 - V max9 >10 V10G min10Table 10 – Specifications relative to water resistanceType of mixITSR (I/C)(%)Method B in compressionAC-BBSG ITSR 70AC-BBME ITSR 80AC-BBA surface course ITSR 80AC-BBA binder layer ITSR 70PA-BBDr ITSR 80BBTM ITSR 80AC-BBM ITSR 70AC-EME ITSR 70AC-GBITSR 70- 59 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -2.4.3 Level 2This level comprises the Level 1 tests (Gyratory Compactor and water resistance)and adds a wheel tracking, or resistance to rutting, test.Table 11 – Specifications relative to the wheel tracking testType of mix Class Number of cyclesSpecification,in % rutting(large device)AC-BBSGAC-BBMEAC-BBAAC-BBM1 ≤ 10% P 102 30000≤ 7,5% P 7,53≤ 5% P 51 ≤ 10% P 102 10000≤ 7,5% P 7,53≤ 5% P 51 3000 ≤ 15% P 152 10000 ≤ 15% P 153 30000 ≤ 10% P 10BBTM10 1 and 2 ≤ 15% P 153 000BBTM6 1 and 2≤ 20% P 20AC-GB2 and 3 10 000 ≤ 10% P 104 30 000 ≤ 10% P 10AC-EME 1 and 2 30 000 ≤ 7,5% P 7,52.4.4 Level 3This level contains the Gyratory Compactor and water resistance tests of level 1, thewheel tracking test of level 2, and includes the step of characterizing the mixture'sstiffness modulus.The stiffness test has been specified within the context of major road-building worksand whenever the targeted layer is involved in the structural function of thepavement. This level means that the product is considered in the Fundamentalapproach of EN standard. The stiffness value at 15°C, 10 Hz or 0,02s is directly usedin the structural design models.Due to their main characteristic, the type testing of AC-GB class 4, AC-BBME andAC-EME mixes must imperatively comprise a stiffness test. For other bituminousmixtures, which are subject to be empirical or fundamental, it may be required.- 60 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -Table 12 – Specifications relative to the stiffness modulusType of mixClassStiffness modulus at 15°C,10Hz or 0,02 sec(MPa)AC-BBSG1 5 500 S 5500Fundamental Approach 2 and 3 7 000 S 7000AC-BBME1 9 000 S 90002 and 3 11 000 S 11000AC-GB2 and 3 9 000 S 9000Fundamental Approach 4 11 000 S 11000AC-EME 1 and 2 14 000 S 14000AC-BBAFundamental Approach1 and 235 5007 000S 5500S 70002.4.5 Level 4This level encompasses the Gyratory Compactor and water resistance tests fromlevel 1, the wheel tracking test from level 2 and level 3 stiffness moduluscharacterization of the mixture; it is duly completed by a determination of fatigueresistance.As level 3, this level is relevant of the Fundamental approach.The fatigue test is to be specified in the case of large-scale jobs and once thetargeted pavement layer is submitted to fatigue. The ε 6value is directly used in thestructural design models.AC-BBME and AC-EME are of course relevant of the fundamental approach. Forother bituminous mixtures, which are subject to be empirical or fundamental, it maybe required.Table 13 – Specifications relative to fatigue resistanceType of mixClassFatigue specification,ε 610°C, 25 HzAnnex A – 2 points trapezoidalAC-BBSGFundamental ApproachAC-BBME1 to 3 ε6 -1001 ε6 -1002 and 3 ε6 -100AC-GB 2 ε6 -80- 61 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -3 ε6 -904 ε6 -100AC-EME1 ε6 -1002 ε6 -1301 ε6 -130AC-BBAFundamental Approach2ε6 -1153 ε6 -1002.4.6 Additional tests- For porous asphalts, EN 13108-7 contains a specification on the vertical orhorizontal permeability according to EN 12697-19; the values extend from 0,1 mm/sto 4 mm/s for both the horizontal permeability Kh and vertical permeability Kv. Thedrainage tests (EN 12697-18) are also addressed in this standard. The specificationsfocusing on the abrasion test for porous asphalt mixes (EN 12697-17) are consideredas not relevant.- For mixes used on airfield runways/taxiways, the resistance to the effect of fuelscan also be prescribed (EN 12697-43), as can the resistance to deicing fluids(EN 12697-41).2.5 Formula verificationThis step is to be performed to validate an existing formula if the asphalt mix designhas been performed at least at level 1 of the type testing routine. The material origin,particle size distribution curve and bitumen content are all considered to remainunchanged.For aggregates however, it is distinctly possible that shape variations for example,imperceptible using typical means of measurement (bulk density, particle sizegrading curve, etc.), exert a significant impact on material behavior.The verification protocol consists of conducting the most selective type of testspossible in order to detect these changes or, instead, to verify the persistence ofcharacteristics inherent in the studied mixture.The most common test is that using the Gyratory Compactor. The selected criterionis the identity of the entire curve at ±1,5%. As a general rule, this criterion is sufficientfor confirming that the mix design has not been altered by major changes. The othercharacteristics (wheel tracking resistance, stiffness modulus, etc.) are thusconsidered to be valid provided the bitumen used matches that of the reference case.Any change in bitumen must trigger a new verification of these characteristics.It could be worthwhile to measure, in specific cases, the characteristic targeted forverification: e.g. wheel tracking resistance on a mix specially designed for thispurpose, by means of the stiffness modulus for a material with a high modulus.- 62 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -2.6 Type testing procedure length and required quantity of materialsPerforming a type testing protocol requires a good ten days or more for level 1, with60 kg of materials and roughly a month to reach level 4, with a total material supplyweighing 400 kg.The amount of time needed for the tests level by level are indicated in Table 14; theestimations shown have been derived by assuming the measurement of themaximum density according EN 12697-5 method A in water and the compressiontest (method B of EN 12697-12) for water resistance.Table 14 – TYPE TESTINGRequired material quantities – Approximate testing durationsLevelTest nameQuantity ofmaterialTestDurationPreparation andancillary operationsTotalduration(includingpreparation)PreparationMaximum density ofthe mixture5 kg for themixture1 day drying + test 2 daysIdentification ofcomponentsParticle sizeanalysis3 kg per particlesize fraction1 day drying + test 2 days1ITSR testMethod B incompression20 kg (Φ 80 mm)40 kg (Φ 120 mm)8 days drying + mixture + test 10 daysGyratory Compactor 30 kg 1 day drying + mixture + test 2 daysTotal - Level 1 40 - 60 kg 12 days2Wheel tracking2 platessample production +50 kg 30,000 cycles - 3storage + V% + testLarge device (2 Slabs)days7 daysTotal - Level 2 110 kg 15 days3Modulus by directtensile test(Annex E)Complex modulus80 kg80 kg3 temperatures3 or 4 loading times4 days1 temperatures1 frequencies1 daysample production +coring/storage + V%+ bonding + testsample production +sawing/storage + V%+ bonding + test21 days18 daysTotal - Level 3 200 kg 21 days4 Fatigue 200 kg 15 dayssample production +sawing + storage + V%+ bonding + test25 daysTotal - Level 4 400 kg 30 days- 63 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -2.7 Summary of test characteristics and methodsThe selected tests and testing procedures included within the scope of the typetesting of asphalt mixes found in EN standards have been laid out in Standard EN13108-20, " Material specification - Type testing". They will be displayed in thefollowing tables by family of mix. The highlighted procedures correspond to the mostwidely practiced at the present time.2.7.1 Asphalt mixesThese are listed in the standard (EN 13108-1) and encompass the types AC-BBSG,AC-BBME, AC-BBS, AC-BBM, AC-BBA, AC-GB, AC-EME.Table 15 – Types of tests for asphalt mixesCharacteristic Testing method ObservationsBinder content(prescriptive)Grading - Particle sizedistribution (prescriptive)Void percentage, includingvoids filled by bitumen andvoids in mineral aggregate,void content Vmax ≤ 7%(prescriptive)Void percentage, includingvoids filled by bitumen andvoids in mineral aggregate,voidcontent7 < Vmax < 10%(prescriptive)Void percentage, includingvoids filled by binder andvoids contained in thegranular skeleton, voidcontent Vmax ≥ 10%EN 12697-1, Soluble bitumencontentand EN12697-39, Bitumencontent by ignitionEN 12697-2, Particle sizedistributionEN 12697-8, Determination ofvoid characteristics ofbituminous specimensApply EN 12697-6 (bulkdensity), Method B, drysaturated surfaceApply EN 12697-5 (maximumdensity - MVR), Method A inwaterEN 12697-8, Determination ofvoid characteristics ofbituminous specimensApply EN 12697-6 (bulkdensity), Method C, paraffinsealedApply EN 12697-5 (maximumdensity - MVR), Method A inwaterEN 12697-8, Determination ofspecimen void percentageApply EN 12697-6 (bulkdensity), Method D bydimensionsWhen type testing is performed withlaboratory-made materials, thebitumen content considered is thequantity of bitumen incorporated intothe mixture. On the other hand, whentesting is conducted with materialsextracted from the plant, the bindercontent of the mix is determined byusing one of these methods.Method not employed in the case oftype testing performed in thelaboratory (see above).Specifications on the void percentagepertain specifically to measurementsconducted on test specimens withinthe scope of a type testing procedure.For example, the void percentage ofimpact-compacted "Marshall"specimens must be determined in thismanner.See above.See above.- 64 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -Characteristic Testing method ObservationsVoid percentages byGyratoryCompaction(prescription)Sensitivity to water(performance-related)Resistance to abrasioncaused by studded tires(performance-related)Resistance to permanentdeformation(performance-related: forroads (a) )For asphalt mixes designedfor axle loads < 13 TResistance to permanentdeformation(performance-related: forroads (a) )For asphalt mixes designedfor axle loads ≥ 13 TResistance to permanentdeformation(performance-related: forairport runways/taxiways (b) )Resistance to permanentdeformation (performancebased)Stiffness modulus(performance-based)2-point fatigue(performance-based) forthe design of pavementsderived from 2-point fatigue4-point fatigue(performance-based) forApply EN 12697-5 (maximumbulk density - MVR), Method Ain waterEN 12697-31, GyratoryCompactor testEN 12697-12, Sensitivity towaterEN 12697-16, Method AEN 12697-22, small device,Method B in air at a specifiedtemperatureEN 12697-22, large device, inair at a specified temperatureEN 12697-34, Marshall testEN 12697-25, Triaxialcompression testEN 12697-26, StiffnessmodulusEN 12697-24, Fatigueresistance – Annex AEN 12697-24, Fatigueresistance – Annex DThis test standard includes adetermination of the void percentagebased on measurement of thespecimen height, which makes thismethod applicable.Method B (compression test) shall beused in France, even the result isnoted ITSR.This reference corresponds to theLPC device and set-up. In selecting atemperature of 60°C and a number ofcycles equal to 3000, 10000 or 30000,the specifications are identical tothose of the former French standard.The resistance to wheel tracking ischaracterized empirically (by creep)using the Marshall test and not thewheel tracking test for airportdesignedasphalt mixes.All procedures for determining thestiffness modulus are considered tobe equivalent. Nonetheless, thesespecifications address moduli at15°C, 10 Hz or 0,02 sec. Someequipment is not capable of yieldingstiffness modulus values for theseloading times or frequencies.Appendix A describes the fatigue testin 2-point bending as compatible withthe design method applied in France.The specifications at 10°C / 25 Hz areidentical to those cited in the formerreference.- 65 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -Characteristic Testing method Observationsthe design of pavements resistance – Annex Dderived from 4-point fatigueResistance to the effectof fuels (performancerelated:for airport runways)Resistance to deicingproducts (performancerelated:for airport runways)EN 12697-43, Resistance tofuelsEN 12697-41, Resistance todeicing productsThis specification is applicable toasphalt mixes used on airfieldsThis specification is applicable toasphalt mixes used on airfieldsabFor asphalt mixes used on pavements and other traffic thoroughfares / roadways, with theexception of airport runways/taxiways.For asphalt mixes used solely on airport runways/taxiways.2.7.2 Very thin asphalt concretesThese material specifications have been listed in Standard EN 13108-2 and aresolely intended for the BBTM type (French acronym for very thin asphalt concrete).Table 16 – Type of tests for BBTM (very thin layer asphalt concretes)Characteristic Testing method ObservationsBinder content(prescription)Particle size distribution(prescription)EN 12697-1, Soluble bitumencontentand EN12697-39, Bitumencontent by calcinationEN 12697-2, Particle sizeanalysisWhen type testing is performed withlaboratory-made materials, thebitumen content considered is thequantity of bitumen incorporated intothe mixture. On the other hand, whenthe testing is conducted withmaterials extracted from the plant, thebinder content of the mix isdetermined by using one of thesemethods.Method not employed in the case oftype testing performed in thelaboratory (see above).Void percentage, includingvoids filled by binder andvoids contained in thegranular skeleton, voidcontent Vmax ≤ 7%(prescription)EN 12697-8, Determination ofspecimen void percentageApply EN 12697-6 (bulkdensity), Method B, drysaturated surfaceApply EN 12697-5 (maximumdensity - MVR), Method A inwaterSpecifications on the void percentagepertain specifically to measurementsconducted on test specimens withinthe scope of a type testing procedure.For example, the void percentage ofimpact-compacted "Marshall"specimens must be determined in thismanner.Void percentage, includingvoids filled by binder andvoids contained in thegranular skeleton, voidcontent 7 < Vmax < 10%(prescription)EN 12697-8, Determination ofspecimen void percentageApply EN 12697-6 (bulkdensity), Method C, paraffinsealedApply EN 12697-5 (maximumbulk density -MVR), Method ASee above.- 66 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -Characteristic Testing method Observationsin waterVoid percentage, includingvoids filled by binder andvoids contained in thegranular skeleton, voidcontent Vmax ≥ 10%(prescription)Void percentages byGyratory Compaction(prescription)Sensitivity to water(performance-related)Resistance to abrasioncaused by studded tires(performance-related)Mechanical stability -OPTIONALResistance to the effectof fuels(performance-related)Resistance to deicingproducts (performancerelatedEN 12697-8, Determination ofspecimen void percentageApply EN 12697-6 (apparentbulk density), Method D bydimensionsApply EN 12697-5 (maximumdensity - MVR), Method A inwaterEN 12697-31, GyratoryCompactor testEN 12697-12, Sensitivity towaterEN 12697-16, Method AEN 12697-22, Large model, inair at a specified temperatureEN 12697-432.7.3 Soft asphalt concretesEN 12697-41 Resistance todeicing productsThese are listed in Standard EN 13108-3.See above.This test standard includes adetermination of the void percentagebased on measurement of thespecimen height, which makes thismethod applicable.Method B (compression test) shall beused in France, even the result isnoted ITSR.This reference corresponds to theLPC device and set-up.This characteristic has not been listedfor CE Marking, but does appear inthe product standard, and can thusbe used as a specification.Table 17 – Type of tests for soft asphalt concretesCharacteristic Testing method ObservationsBinder content(prescription)Particle size distribution(prescription)EN 12697-1, Soluble bitumencontentand EN12697-39, Bitumencontent by calcinationEN 12697-2 Particle sizeanalysiscf. comments in table 15.cf. comments in table 15.- 67 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -Characteristic Testing method ObservationsVoid percentage(prescription)2.7.4 Hot Rolled AsphaltEN 12697-8, Determination ofspecimen void percentageApply EN 12697-6 (bulkdensity), Method B, drysaturated surfaceApply EN 12697-5 (maximumbulk density - MVR), Method Ain waterThese specifications are listed in Standard EN 13108-4.Table 18 – Type of tests for Hot Rolled AsphaltBinder content(prescription)Characteristic Testing method ObservationsParticle size distribution(prescription)Void percentage, includingvoids filled by binder and voidscontained in the granularskeleton (prescription)Sensitivity to water(performance-related)Resistance to abrasioncaused by studded tires(performance-related)Resistance to permanentdeformation (performancerelated)Stiffness modulus(performance-related)Resistance to the effect offuels (performance-related: forairstrips)Resistance to deicingproducts(performance-related: forairstrips)EN 12697-1, Soluble bitumencontentand EN12697-39, Bitumencontent by calcinationEN 12697-2 Particle sizeanalysisEN 12697-8, Determination ofspecimen void percentageApply EN 12697-6 (bulkdensity), Method A, dryconditionApply EN 12697-5 (maximumbulk density - MVR), Method Ain waterEN 12697-12, Water resistanceEN 12697-16EN 12697-22, small model,Method A in air and Y cyclesEN 12697-26EN 12697-43EN 12697-41cf. comments in table 15.cf. comments in table 15.- 68 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -2.7.5 Stone Mastic AsphaltThese specifications are listed in Standard EN 13108-5.Table 19 – Type of tests for the Stone Mastic Asphalt materialCharacteristic Testing method ObservationsBinder content(prescription)EN 12697-1, Soluble bitumencontentand EN12697-39, Bitumencontent by calcinationcf. comments in table 15.Particle size distribution(prescription)Void percentage, includingvoids filled by binder(prescription)Void percentages ofGyratory Compactorspecimens(prescription)Binder drainage(performance-related)Sensitivity to water(performance-related)Resistance to abrasioncaused by studded tires(performance-related)Resistance to permanentdeformation (performancerelated)For Stone Mastic Asphaltmixes designed with axleloads < 13 TResistance to permanentdeformation(performance-related: forroads (a) )For Stone Mastic Asphaltmixes designed with axleloads ≥ 13 TResistance to the effectof fuels (performancerelated:for airstrips)Resistance to deicingproducts (performancerelated:for airstrips)EN 12697-2, Particle sizeanalysisEN 12697-8Apply EN 12697-6 (bulk density),Method B, dry saturated surfaceApply EN 12697-5 (maximumdensity), Method A in waterEN 12697-31, GyratoryCompactor testEN 12697-18, Drainage testEN 12697-12, Water resistanceEN 12697-16EN 12697-22, small model, in airat a specified temperatureEN 12697-22, large model, in airat a specified temperatureEN 12697-43EN 12697-41cf. comments in table 15.This test standard includes adetermination of the voidpercentage based on measurementof the specimen height, whichmakes this method applicable.Indirect tensile method or method Busing compression.This reference corresponds to theLPC device and set-up.- 69 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -Figure 19: Small-scale rutting tester model operating in air2.7.6 Porous AsphaltThese specifications are listed in Standard EN 13108-7 and encompass BBDr(French acronym Bétons Bitumineux Drainants for porous asphalts).Table 20 – Type of tests for the porous asphaltBinder content(prescription)Characteristic Testing method ObservationsEN 12697-1, Soluble bitumencontentand EN12697-39, Bitumencontent by calcinationcf. comments in table 15.Particle size distribution(prescription)Void percentage(prescription)Void percentages by Gyratorycompaction(prescription)EN 12697-2, Particle sizeanalysisEN 12697-8, Determination ofspecimen void percentageApply EN 12697-6 (bulkdensity), Method D bydimensionsApply EN 12697-5 (maximumdensity - MVR), Method A inwaterEN 12697-31, GyratoryCompactor testcf. comments in table 15.This test standard includes adetermination of the voidpercentage based onmeasurement of the specimenheight, which makes thismethod applicable.- 70 -


LPC Bituminous Mixtures Design Guide- Type testing of bituminous mixtures -Characteristic Testing method ObservationsPermeability (performancerelated)Sensitivity to water(performance-related)Bitumen - aggregate affinity(performance-related: for airportrunways/taxiways)Binder drainage (performancerelated)Mass loss (performancerelated)Resistance to the effect offuels (performance-related: forairstrips)Resistance to deicingproducts (performance-related:for airstrips)EN 12697-19, Laboratory-basedpermeability testEN 12697-12, Water resistance Method B(compression test)shall be used in France, eventhe result is expressed as ITSR.EN 12697-11, Binder -aggregate affinity, Part C: StaticmethodEN 12697-18, Drainage testEN 12697-17, Abrasion testEN 12697-43EN 12697-41The "Cantabre" test (deemednot pertinent for specificationspurposes).- 71 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -3 MIX DESIGN PROCEDUREThe procedure employed to design material mixes has not been codified. The focusherein relies upon meeting the requirements identified from the type testing stagedescribed in Part 2. The mix design process begins by selecting the set ofcomponents: aggregates, fines, binder, and additives. In some instances, thesecomponents may be imposed by the contracting party. Knowing the characteristics ofmix constituents is critical as of the initial mix design phase and will also prove usefulfor all subsequent mix adjustments/refinements should test results not comply withspecifications. The procedure entails adjusting the mix composition using theGyratory Compactor test, complemented afterwards by the set of tests stipulated forthe particular testing level in correspondence with the chosen design. This procedurehas been laid out in the diagram below. The sections that follow will detail thesevarious stages in association with the recommendations issued by practitioners.Change incomponent(s)Selection of componentsDesign of theprototype mix compositionAdjustments of theparticle grading curveGyratory CompactortestyesnoType testing3.1 Component selection3.1.1 Aggregates3.1.1.1 Fines and added fillersAccording EN 13043, fines and added fillers are characterized after a dry sieving witha 0,125 mm sieve by a voids of dry compaction test (Rigden Void Index), by a ∆T R&Btest and by the identification of the methylene blue value MBF.- 73 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -ChoiceThe added filler is not, in all instances, definitively chosen at the same time asestablishing the mix design. In some regions, the added filler stems from just a singlesource, thereby simplifying the procedure. While several different plants may able toaccommodate supply needs, the mix designer must be provided an identified set ofsamples and then select a "feasible" supplier. The mix composition can also beproduced using the same kind of "average" filler under all conditions.TypeFine limestone aggregate tends to be predominant as a choice of added filler, yetother filler types may be used as a replacement or complement by virtue of theirspecific properties. For instance, cement may be used as a replacement for thelimestone filler, yet it would be preferable to limit its concentration to just 3% or 4%.Beyond this threshold, cement hydration in the mixture can exert influence on the I/Cratio (Duriez test corresponding to method B of EN 12697-12); moreover, crackingproblems may arise as well.Calcium hydroxide (quicklime) is introduced into the mix in order to prevent the socalled"soup" phenomenon from appearing; such a phenomenon can be observedduring mixing as water gets held by porous aggregates. It would be worthwhile to usecalcium hydroxide (quicklime) for improving the level of water resistance; in addition,its concentration would need to be limited to 1% (due to the risk of swelling), andprecautions to avoid inhalation would need to be taken.The active filler is a mix of limestone fines and calcium oxide (slaked lime), which hasthe same use properties as quicklime.Slaked lime gets added as a drainage retardant on porous asphalts (PA-BBDr). Itsconcentration of between 10% and 25% lime, as compared to limestone filler, allowsobtaining a mastic whose ∆T R&B increases by 4°C to 7°C with respect to the ∆T R&Bvalue of the base filler.Slate is introduced for its extremely high stiffening power (i.e. a ∆T R&B of more than38°C, a methylene blue value of around 0,3 g / 100 g, a Rigden Voids Index in theneighborhood of 45%, and an absorbent power lying near 26).Should fly ash from coal-fired power plants be used, it would be advised to monitormass density values as these may fluctuate. The additives are composed of hollowspheres and their absorbing power varies widely.Similarly for cement fillers, which are industrial by-products, the methylene blue valueneeds to be verified.The effect of the presence of ultra-fine particles on the properties of mastic andasphalt mixes is not well known. An experiment focusing on a specially-preparedlimestone filler with an increasing proportion of ultra-fine particles did not concludethe presence of any significant effect on ∆T R&B .- 74 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -MasticThe combination of bitumen and filler within a hydrocarbon mix gives rise to a masticwhose properties will influence a portion of mix characteristics. Said properties arebasically evaluated via the ∆T R&B value. High ∆T R&B values tend to enhance ruttingresistance, and excessive values of ∆T R&B could constitute a cracking risk.Voids in dry compacted filler (Rigden Void Index) v: High Rigden Void Indexvalues generally imply a rise in binder content (also in richness modulus), so as toyield a volume of free bitumen equivalent to that obtained in a readily-availablematerial.HarmfulnessExample – Effect of clay content on mix characteristics:The inclusion of clay into the fines of a crushed aggregate for the purpose of experimentallyincreasing the methylene blue value (bentonite, kaolinite, illite) has induced the following effects onthe characteristics of a mix (AC-BBSG, AC-GB):– Rise in the percentage of Gyratory Compactor voids (+ 2 for VB = 2g/100g)– Decrease in rutting depth (2,3 mm for VB = 4g/100g)– No visible effect on the I/C (r/R Duriez test) ratio (at 7, 14 or 28 days)– Significant stripping of mortar even after 7 days, as I/C drops 0,10 to 0,25 pointsKeep in mind that the studied mix was artificial. Transposing results to commonly-used mixes is notalways straightforward.[LPC Report No. 14]3.1.1.2 Fine aggregateThe criteria relevant to sands or fine aggregate that serve to influence asphaltmixtures are as follows:Particle size distribution (grading) curveSpecial consideration needs to be given to hollow curves with a very small finescontent that hinders mix compactability.AngularityThe angularity of fine aggregate exerts a major impact on the mixture's ruttingresistance.The characteristics of how crushed aggregates are produced even when derivedfrom solid rocks can heavily influence mix characteristics. Aggregates could displaychipped edges due to processes involving recycling, grinding, etc. Their internalfriction thus drops considerably and might alter mix stability. This problem couldultimately be revealed through the fine aggregate flow coefficient of the testdescribed in EN 933-6. A visual inspection using binoculars remains the mosteffective means of detection for a well-trained eye.- 75 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -Example – Effect of angularity (with solid rock):In two AC14-BBSG samples containing approximately 30% fine aggregate of the same origin, yetfrom different production facilities (these fine aggregates differ by 6 seconds when submitted to theflow test), it was found that:Ground solid rock => wheel tracking test result: 8% after only 1000 cyclesCrushed solid rock => wheel tracking test result: 5% after 30000 cycles[Corté et al, 1994]Whenever the percentage of voids for a mix becomes excessive, the inclusion of asmall proportion of totally rounded fine aggregate serves to reduce this percentage.The following limitations must nonetheless be noted: the use of fine totally roundedaggregate on a road pavement is strongly discouraged, while application of this typeof fine aggregate must be confined to road mixes submitted to very limited risks ofrutting. The suggested concentration is held to 10% for asphalt concretes for surfacecourses and must not exceed 20% for base courses.The effect of low angularity may, in some instances, be compensated by using a"hard" grade binder when the mix is being applied as a base course or foundation. Itis still advised, in all cases, however to ensure stability of the granular skeleton.Resistance to fragmentation or to wear (Hardness)Whenever physical characteristics differ among the mix's various granular fractions,the softest aggregate may undergo attrition. One illustration would be the frequentcase of finding a soft sand along with harder coarser aggregates. Some distinctionsmight be limited to just a single category. The converse (i.e. harder sand with softercoarse aggregates) could not be accepted for application as a wearing course.Should the origin of the fines fraction be different from that of the coarse aggregates,it would be necessary to submit the fines to a friability test, Vss = 40 for a all-inaggregate 0/4, and Vss = 45 for a fine aggregate 0/2.3.1.1.3 Coarse aggregatesThe set of criteria relative to coarse aggregates that serve to influence bituminousroad-building materials are as follows:Type of rockFrictional materials: Materials are said to be "frictional" when the percentages ofvoids observed on Duriez test specimens (Method B of EN 12697-12 is derived fromDuriez test) lie close to values recorded in situ, whereas the Gyratory Compactorindicates a lack of workability (as translated by an excess in voids on the order of 4-5%) for the specified number of gyrations.This phenomenon has been observed with certain basalts, granites and gneiss.Workable materials: Materials are said to be workable if, despite exhibiting highangularity, their standard particle size distribution leads to a small percentage ofvoids.- 76 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -Porous materials: These materials absorb, through their inherent porosity, a portionof the bitumen and engender mixing difficulties. This phenomenon has beenremarked with basalts, slag and dolomitic limestone. The level of absorption can bemeasured by means of lacquering the aggregates with bitumen and then recordingthe maximum density (MVR) value both before and after lacquering.Evolutive materials: This category of materials displays alterations in characteristicsover time and, for example, would comprise steel slag and LD dross.Example – The case of dross from the Fos-sur-Mer "LD" steel mill:These aggregates are of artificial origin.They have been used:– for several years in the form of 0/4 all-in aggregate, to adjust angularity on overlyworkablemix designs (AC-BBSG, AC-BBM, BBTM); and– much more recently in the form of coarse aggregates, as an alternative to aggregateswith high CPA values[ Former test for PSV : PSV= 100CPA + 1,5] (0,5 to 0,6), whichprove to be rare and expensive in the region around Fos-sur-Mer (south of France).Their mass density level is quite high (3,1 to 3,7 g/cm 3 ).These materials are steelmaking by-products contained in "LD" converters, which serve to transformhematite pig iron into steel. Prior to application, they undergo the following treatments:1. Metal removal;2. Crushing to 0/2 mm;3. Bulk storage for a period ≥ 1 year in order to slake nearly all of the quicklime contents;4. Screening.This procedure is presumed to cancel the effects produced by aggregate swelling when hydratingthe lime contained in the original materials.The literature on this topic and procedure is vast.[CTPL publication, CRR Study Series]ShapeAggregates shaped too much like cubes could lead to excessive workability. Theflakiness Index FI should, as a preferred value, lie between 10 and 15.Example – "Shape" effect of a coarse aggregate on mix behavior:Effect on void content: AC14- GB containing 4% (out) bitumen (Solid rock N - crushed)Flakiness2/14 fraction% voids after 100gyrationsAC14-GB3,7 5,89,5 8,9- 77 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -Effect on wheel tracking: AC14-BBSG containing 5,7% (out) bitumen,Solid rock C - ground – Solid rock N - crushedFlakiness2/14 fractionRut depth (in mm)after 1000 cyclesAC-BBSG3,7 15Rut depth (in mm)after 3000 cyclesAC-BBSGDeformation too highto be measured9,5 9 18AngularityThis characteristic influences mix stability and affects the material's surfacecharacteristics.The "type of aggregate" parameter could produce an effect 3 to 4 times greater than that of the"bitumen grade" parameter with respect to rutting.[AAPT 1988, v 57]An additional 7°C over the bitumen R&Β would be needed in order to compensate for "poorangularity".Aggregate processing modeThe type of crusher used and its mode of operations affect, for a given crushing ratio,both the shape and aspect of aggregate edges. Mix performance (i.e. wheel trackingand compacity), as a consequence, also gets affected.Example – Effect of crushing mode on a alluvial AC10-BBSG from the Durance:(1) Tertiary Gyratory crusher(2) Vertical anvil axis(3) Vertical pebble box axisCrushing modeGyratorycrusherAngularityfineaggregate(flow time)Angularitycoarseaggregate(flow time)CrushingratioR cGyratoryCompactor60 gyrationsVoid %Rutting at3000 cycles -% rut depthRutting - after30000 cycles39 124 4 9,8 3,2 5,7Anvil axis 37 122 4 9,7 3,2 5,4Pebble box axis 33 106 4 6,7 10,8Deformation toostrong to bemeasured[Mines and quarries, October 1996, Volume 78]- 78 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -Other characteristicsA high coefficient of dilatation weakens the mix at low temperature… [RGRA 753, p. 52]To shade the material or to complement the use of both light and colored binders inan effort to obtain a more distinct hue, specially-colored aggregates may be chosen(these choices would include the fine aggregate component).Light-colored aggregates are sometimes employed to: reduce the "black body" effectof mixes, lessen pavement heating, and thereby lower the risk of rutting. Suchaggregates can also be used as a surface layer in tunnels to limit the need foradditional artificial lighting.As an illustration, the introduction of quartzite (white) instead of the more conventional diorite (gray)has resulted in an observed drop of between 2°C and 5°C (between normal and exceptionalsummertime conditions) within the first centimeter of pavement. The associated use of a light-coloredbinder gives rise to a further 3°C decrease.[Light-colored asphalt concretes on the Paris ring road, RGRA 735, p. 57, December 1995]3.1.2 Binder3.1.2.1 OriginThe origin of the binder used on a road-building site is not always known whendesigning the material mix. To conduct the Gyratory Compactor test, since bitumenorigin does not affect the result, it is possible to implement the same grade bitumenas that specified for the works. In order to characterize a mix based on the watersensitivitytest by compression, as well as on the wheel tracking test and adetermination of the stiffness modulus or fatigue resistance, the origin of the bitumenused will influence ultimate test results. Should the specified bitumen be unavailable,it would be appropriate to use either a "feasible" bitumen or a "standard" bitumenvery familiar to the mix designer. Once the actual "project" bitumen is effectivelyknown, an estimation of the alteration introduced needs to be carried out.3.1.2.2 Type of bitumenThe choice of bitumen must enhance the attainment of required productperformance. Some performance measures have been included in the type testingprotocol conducted on the mixtures (i.e. water resistance, rutting resistance, stiffnessmodulus, fatigue resistance), yet others are not directly expressed via test results(material aging, oxidation, "top-down" cracking, etc.). A series of empiricalspecifications based on more conventional tests can then be developed.Paving grade bitumenTo better prevent against cracking risks under severe traffic and climatic loadingconditions, it would be advised to select the softest grade compatible with ruttingresistance-based requirements. For purposes of illustration, the following tendenciesmay be considered (from the French Standard Mix Application Guide).- 79 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -Table 21– Suggested bitumen grade by mix typeType of mix Loading Suggested gradeMixes for wearing courses AC-BBSG,AC-BBM, BBTM, PA-BBDr and AC-BBA materialsMixes for wearing courses AC-BBSG,AC-BBM, BBTM and AC-BBA materialsMixes for base courses /foundation layersHeavyLight35/5050/70 (airfield pavement NS3)20/30 may be used for class 3 of AC-BBSGand AC-BBME50/7070/100 at higher altitudes, and in continentalzones and airfield zones submitted to lighterloads (NS1, NS2)35/50Lower thermal susceptibility bitumenThis category of pure bitumen has been specially produced and features apenetration at 25°C that corresponds with the standardized grade (e.g. 35/50 or50/70), yet whose ring and ball temperature typically exceeds the standardized limitfor the corresponding grade. The Fraass temperature is also lower than that ofsimilarly-graded pure bitumen samples (≤ -15°C). They are used in particular forimproving the rutting resistance properties of materials."Hard" bitumenThis category of pure bitumen is obtained by means of a direct refining process anddisplays a penetration of less than 25 1/10 mm. Two categories 10/20 and 15/25 aredefined according to EN 13924. The French recommendation for the ring and balltemperature is between 60°C and 76°C for 10/20 and between 55°C and 71°C for15/25. The Fraass temperature (out of the French recommendation) lies near 0°C(from +3°C to -8°C). The mixing temperature exceeds by approximately 20°C thatassociated with conventional bitumen mixes. The primary application of this type ofbinder relates to the EME high-modulus materials. The hardness of this type ofbitumen can induce brittleness at low temperature; it would thus be advised to usesuch mixes along with thermal protection when employed in harsher climates.Modified bitumenModified bitumen materials are bituminous binders whose properties have beenaltered by the introduction of a chemical agent that, added to the basic bitumen, actsto modify both the chemical structure and physical and mechanical properties. In allcases for such materials, precautions must be taken to avoid the risk of instability,creaming and sensitivity to thermal loading history.Section 1.4.2.2 provides a description of the main types of modified bitumen. Theshortfall in performance-based specifications on these materials necessitates thesystematic assurance that use of such a binder serves to obtain the desired mixperformance, hence the quality of modified bitumen and, consequently, the resultantmix properties are not solely dependent upon polymer content. Moreover, it shouldbe pointed out that for modified binders, the ring and ball temperature does not- 80 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -constitute a relevant criterion when it comes to evaluating asphalt mix behavior athigh service temperatures.Modified binders are basically used in surface layers in both BBTM and BBDrmaterials. The ultimate application is what distinguishes the various modified binderfamilies for individual supplier-specific uses. Some products have been the topic ofTechnical Guidelines, published by the SETRA Highway Engineering Agency, whichsets forth use conditions and performance levels obtained on reference jobsites.Pigmentable bitumenThis category of bitumen and the resultant mixes show greater susceptibility totemperature than materials containing "normal" bitumen. Such components arereserved for more urban type applications or one-off uses intended to render laneindications more easily legible.Synthetic bindersSynthetic binders display a number of behavioral differences in comparison withconventional bitumen, namely:- their susceptibility to temperature may be very different from that of a similarlygradedstandardized bitumen; and- their mixing temperature must be indicated by the supplier; it may vary on theorder of 15°C with respect to that of a pure bitumen of the same consistency.Their range of application overlaps with that of pigmentable bitumen.Bituminous binders with mineral loadsThese ready-to-use binders are obtained from plant mixtures of pure bitumen andmineral loads, e.g. lime. Binder content differs from bitumen content, and theobjective herein tends to focus on "stiffening" the mix.Agrochemical bindersThese binders are made from vegetal matter without any petrochemical byproduct.The result is transparent and may be colored. Its applicability is currently beingassessed.3.1.3 AdditivesSection 1.4.3 provides a comprehensive description of the primary additives.3.1.3.1 Effect of type of additivePolyethyleneThis additive is intended to improve the level of rutting resistance and increase thestiffness modulus; it partially associates with the bitumen.The concentration level typically lies between 0,4% and 1%, with respect toaggregate quantity. It should be remarked that polyethylene at the melting point playsthe same role as bitumen. A standard concentration of polyethylene thus serves todecrease the binder concentration of the reference material by some 0,15%.- 81 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -Similarly, the increase in fatigue characteristics observed when adding polyethyleneis solely correlated with the corresponding rise in binder quantity.Example – Effect of polyethylene concentration (from cable waste) on rutting resistanceTest conducted on a AC14-BBSG mix containing 32% finely-crushed aggregate,initially leading to 15% rutting after 3000 cyclesNOTE: The mix's bitumen content has been lowered by 0,15%, in comparison with the reference mix,to account for the addition of polyethylene.Polyethylene concentration(%, with respect to the dry aggregate)Rut depth after 30,000 cycles(mm)0,5 90,8 51,1 4[Experiment conducted on aggressive loads, No. 3, Fatigue Carrousel]PolymersThese additives are intended to decrease the effect of binder susceptibility.Fine rubber crumb fraction and 2/6 rubber aggregatesThese additives contribute to improved cracking resistance, in addition to dampingthe impact from tires.New and recycling fibersIncorporated at the time of mixing, these fibers act like a bitumen reservoir once inthe mix; they can either increase bitumen content, without raising the risk of rutting(added to BBTM and SMA mixtures), or avoid drainage problems (for PA-BBDr).Depending on the type of fibers added, the mode of laboratory preparation must beadapted while continuing to respect the mode selected for including this additive in anindustrial setting.The fibers may be mixed to the binder either as a preliminary step or introduced intothe dry mix or perhaps after incorporation of the bitumen.3.1.3.2 Natural bitumen and asphaltsThis category of additives is to be used as a substitution for directly-distilled bitumenin order to obtain a stiffer mix by means of a combined binder hardness and addedfiller effect.3.1.3.3 PigmentsThe concentration of pigments depends on the desired effect, aggregate color andtype of bitumen. For a light-colored synthetic binder, this concentration lies on theorder of 0,5% and can rise as high as 2%. With a pigmentable bitumen, theconcentrations are higher, reaching the neighborhood of 2,5% to 4%. This case isgenerally limited to use of the color red.It would be necessary to consider the pigment concentration like fines within the mix.- 82 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -The product is then incorporated into the dry mixture prior to adding the bitumen.The mix's mechanical characteristics, especially water resistance and if applicablerutting resistance, are to be verified. Oxides can actually influence binder-aggregateadhesion and the choice of associated bitumen (either pigmentable or synthetic) caninfluence rutting resistance.3.2 Relationships between binder properties and mix properties3.2.1 Penetrability and ring and ball temperatureThe test of penetrability at 25°C is correlated with stiffness of the mix at servicetemperatures. The stiffness modulus of bitumen may be deduced from both thepenetration test at 25°C and the ring and ball temperature, by means of the Van derPoel abacus (see Fig. 29).Ring and ball temperature is an effective indicator of the binder's contribution torutting resistance. This criterion loses its relevance however for modified binders.Example – Effect of ring and ball temperatureOn 3 types of asphalt mixes, a 7°C rise in the ring and ball temperature of a bitumen allowsincreasing tenfold the number of cycles leading to a given rutting depth.3.2.2 The SHRP criteriaThe Strategic Highway Research Program (SHRP) set up in the United States hassought to define the relationships between binder characteristics and mixcharacteristics. The tests conducted on binders have been aimed at ascertainingrheological aspects. The binder performance – mix performance relationships are thecurrent focus of research efforts. A few of these relationships have already beenpublished, yet their pertinence for French mixes still needs to be verified.SHRP criteria and tests conducted on asphalt mixesAccording to the SHRP, rutting resistance is effective if G*/sin δ > 1 kPa (for new binder) and> 2,2 kPa (for binder having undergone RTFOT).This relationship is not always verified with the LPC rutting tester.In contrast, the criterion G*/sin δ > 3.8 kPa leads to low rutting rates [RGRA 730].The SHRP criterion relative to fatigue resistance is expressed as: G*sin δ < 5 kPa (RTFOT + PAV).A verification on AC10-BBSG mixes serves to confirm this trend, although the correlation is not verystrong. Sin δ does not contribute any more than G*, and ε 6 is not directly correlated. The slope of thefatigue line enters into consideration.Cold resistance: The SHRP criteria are: S(60) < 300 MPa and m > 0,3 (with the doubt over whethereither of the two criteria is being met: a tensile deformation test at failure > 1% is thus conducted).The criteria selected in France are: temperature isomodulus I G*I = 300 MPa for a 1000 s loadingtime and slope m. Correlation with the theoretical brittleness temperature proves to be strong.- 83 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -3.2.3 Origin of the bitumenBoth the origin and processing mode for bitumen materials may exert a significantinfluence on mix characteristics. Some test results depend heavily on theseparameters – a few examples have been provided below:ε 6 and the origin of bitumenThe fatigue resistance ε 6 measured by the deformation test required on mix specimens with bitumenfeaturing the same characteristics, yet of different origins, varies between 88 µdef and 150 µdef, allother parameters being held the same.[Statistical study of the effect of asphalt mix composition on material fatigue behavior,F. Moutier, BL, No. 172, p. 40]Relationships between the stiffness moduli for both binder and mixOn any given mix, relationships between the stiffness moduli of both the binder and mix (containingmodified binders) of the type lg (E*) = 0,71 *lg (G*) + 3,04 have been established.[RGRA 739, p. 22]- 84 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -3.3 Initial composition by type of materialDepending on the set of requirements and available materials, the mix designerdetermines a composition that corresponds to an initial targeted particle sizedistribution curve, as well as a bitumen content and, ultimately, the proportions ofadmixtures.This initial composition is established in accordance with knowledge derived frompreviously-studied mixtures, initial mix design curves, mix family ranges and bindercontent (or richness modulus) values while incorporating the effects of additives andthe absorbing power of fillers on binder content.The initial compositions (particle size distribution curve, binder content) by type ofmaterial will be discussed in the following sections and listed in the summary tablepresented in Appendix E and in Appendix F.3.3.1 Asphalt Concretes for base course – Grave-Bitume AC-GB and HighModulus AC-EMEFigure 20: Cross-section of a Grave-Bitume AC-GB mix3.3.1.1 Remarks concerning mix componentsAggregatesFor some of the fines from basalt aggregates, crushed slag and highly-acidic granite,either active fillers or hydrated lime needs to be used.Most hard limestone sand generates a high level of workability: the percent passingthe 2-mm sieve on the AC-GB particle size distribution curves must be reduced toapproximately 30% or else the wheel tracking test would have to be considered.Some of the natural fillers from fine aggregate are noxious despite being able tosatisfy cleanliness specifications. As an example, dolomite leads to water resistanceproblems, as do certain forms of tuff, even though the methylene blue value seems tobe adequate.- 85 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -The amphibolites-gneiss and a number of porphyries yield low I/C (r/R) ratios(whereas amphibolite-diorite ratios are very strong).For the AC-EME and AC-GB mixes, it is possible to correct for the angularity effectthrough bitumen hardness and concentration. The durability however has not beenestablished.The hard limestone materials make it possible to obtain high readings of compacity,even with moderate binder content. This high compacity, coupled with relatively lowbinder content, has resulted in increased stiffness modulus values.For some granite materials, water resistance still needs to be verified.Bitumen and additivesFor Grave-Bitume AC-GB:As a general rule, 35/50-grade pure bitumen is used. Grade 50/70 may also beemployed for convenience sake, for example at stationary mixing plants.In mountainous regions or in the case of low-level loadings (as intended by the MixStandards Application Guide), implementation of the 50/70 grade is indeed possible.On the other hand, a grade above 70/100 must not be used.Within specifically-designated zones (traffic > T0 [more than 750 lorries per day],channeled traffic flows, slow speeds < 40km/h, a ramp inclined at over 5%), it isadvised to select the 20/30 grade or a special bitumen with low thermal susceptibility,should the desired result not be reached with a 35/50 grade.Adding polyethylene to bitumen-aggregate mixes does not seem to be beneficial(rarely justifiable given current mix designs).For High Modulus Asphalt concrete mixtures AC-EME:These are most often produced using an hard-grade bitumen as stipulated byEN 13924 and in conjunction with 10/20 or 15/25 grades. The recommendedcharacteristics for this type of binder are as follows:- standard penetration: 10 to 25 1/10 mm; and- ring and ball temperature: between 62°C and 72°C, or even 80°C.The 20/30 grade may be acceptable along with other grades (35/50 in particular),combined with admixtures (e.g. natural bitumen) or polyethylene.Polymer-modified bitumen serves to increase the value of ε 6 .The addition of 0,7% polyethylene within a 35/50-based mix offers a potential gain ofapproximately 20% in stiffness modulus.The presence of fibers exert little influence on modulus values.3.3.1.2 Composition of the granular mixParticle size distribution curves tend to be continuous. It is possible to introducediscontinuities into the [4/6] or [6/10] distribution curve. Discontinuities typically havelittle impact on material characteristics. Should the curve show coarse granularity(percent passing 2-mm sieve on the order of 28%), it would be necessary to raise thefiller content to about 7,7%.Table 22 presents the initial grading curves for AC20 or AC14 Grave-Bitume AC-GBand High Modulus Asphalt concrete AC-EME mixes. The French foreword of EN- 86 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -13108-1 also calls for the possibility of producing a AC10-EME, whose correspondinginitial grading curve has been listed in Table 23.Table 22 – Initial AC20 or AC14 Grave-Bitume AC-GB and High Modulus Asphalt Concrete AC-EME grading curveSieve passing,in mmD = 20 mm or 14 mmTypical range of variationsMinimum Target value Maximum6,3 45 (50 for 0/14) 53 65(70 for 0/14)4 40 47 602 25 33 380,063 5.4 6.7 7.7Table 23 – Initial AC10-EME grading curveSieve passing,in mmD = 10 mmTypical range of variationsMinimum Target value Maximum6,3 45 55 654 522 28 33 380,063 6,3 6,7 7,23.3.1.3 Bitumen contentThe bitumen content at the beginning of this study is taken from Table 24 orcalculated from the specific surface area of the mix, the maximum density (MVR)value and the minimum richness modulus associated with the standard. Forinformation, the previous “external binder content” is also mentioned in table 24- 87 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -Table 24 – Typical initial binder content of AC-GB and AC-EME (richness modulus)AC-GB2 AC-GB3 AC-GB4 AC-EME1 AC-EME2D in mm 14 20 14 20 14 2010 or142010 or1420Binder content B minfor ρ = 2,65 g/cm 3 4,0 4,0 4,5 4,4 4,7 4,6 4,0 4,0 5,4 5,3Binder content B minfor ρ = 2,75 g/cm 3 3,9 3,9 4,3 4,2 4,5 4,4 3,9 3,9 5,2 5,1Typical target ofrichness modulus K2,5 2,8 2,9 2,5 3,4External bindercontent TL ext for 4,0 4,0 4,5 4,4 4,7 4,6 4,0 4,0 5,5 5,4ρ = 2,75 g/cm 33.3.1.4 Experimental resultsA sample of experimental results capable of influencing the mix designer is given inthe following study:- 88 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -Influence from type of aggregate and rheology of hard bitumen on the properties of hot asphaltmixtures used as a pavement base course and foundation layerP. Bauer - S. Glita - P. Chaverot - J.M. Michou - P. Perdereau - Y. VincentEurasphalt & Eurobitume 1996. 4.050Bitumen characteristicsUnits Mixelf 10/20 15/25BeforeRTFOTAfterRTFOTBeforeRTFOTAfterRTFOTBeforeRTFOTAfterRTFOTPenetrability at25°C1/10 mm 15 10 13 10 21 13Ring and balltemperature °C 68 73,5 69 75 62 72Constant richness modulus: 3,65; AC14-EME - type 2; particle size distribution curve ~ constantAggregate characteristics: 4 origins: D; Q; C; SC (SC is an alluvial material)Results from Gyratory Compactor testingAggregate D Aggregate Q Aggregate C Aggregate SCSlope K 3,65 3,44 4,12 3,27Voids calculated for 1 22 21 23,9 19,4gyration % V 1Voids at 100 gyrations %V 1005 5,1 4,8 4,2Results from wheel tracking tests60°C, 30,000 cycles: rutting depth less than 5 mm, regardless of binder and aggregate, except foraggregate SC (6 to 8 mm).Stiffness modulus test in direct tension10°C, 0.02 sec: The stiffness modulus exceeds 20000 MPa.Aggregate origin induces a 20% variation (Mixelf bitumen).(increasing trend C -> SC -> Q ->D)Bitumen origin leads to a 10% deviation for aggregate C (15/25 -> {10/20 & Mixelf}) and an 18%deviation for aggregate D (15/25 -> {10/20 & Mixelf}).Complex modulus test15°C, 10 HzAggregate origin produces an 18% deviation (Mixelf bitumen) (C=SC=Q->D)No "aggregate" effectFatigue test- 89 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -3.3.2 Thick layer mixtures for surface or binder course – AC-BBSG, AC-BBS,AC-BBMEFigure 21: Cross-section of a AC-BBSG(Asphalt Concrete Béton Bitumineux Semi-Grenu)Figure 22: Surface appearance of a AC-BBSG(Asphalt Concrete Béton Bitumineux Semi-Grenu)3.3.2.1 Remarks concerning mix componentsAggregatesFor some fine aggregates from basalt aggregates, crushed slag and certain highlyacidicgranite materials, either mixed fillers or lime must be employed.Most hard limestone fine aggregates provide for a good level of workability: thepercent passing 2 mm on the AC-BBSG or AC-BBME grading curves must bereduced to approximately 30% (or even less).Some natural fillers from fine aggregate are noxious even if harmfulnessspecifications have been satisfied. For example, dolomite (cleanliness of sands withan sand equivalent rating ≥ 70, the blue value (stain) ≥ 2 g (i.e. approximately MBF ≥2,000 g/kg)) leads to water resistance problems, as do certain forms of tuff, despite ablue value that lies on the order of 0,8 g.The amphibolites-gneiss yield poor I/C (r/R) ratios for the watersensitivity, while theamphibolite-diorite results are quite strong.The brittleness of the fine aggregate would provide an indicator of the contributionfrom fines towards rutting resistance.The angularity of fine aggregate affects mix stability.It is advised to be cautious of ground fine aggregate and fine aggregate (or all-inaggregate) output from crushers with a revolving floorplate. The shape of mineralparticles could make the mixture more sensitive to rutting.- Granite: water resistance requires verification.- Basalt: binder content to be adapted to better account for eventual absorption.- Limestone: coarse limestone aggregates are not permitted for use in wearingcourses (on the national highway network).- 90 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -- Angularity and shape: the angularity of coarse gravel influences texture, as doesthe coarse aggregate shape. An overly regular shape would be deleterious and isto be avoided.The flakiness index FI must preferably lie between 10 and 15.For a AC14-BBSG mixture:A percent passing of 34% with 2 mm sieve conducted at a texture in situ at ATD =0,4 mm.A percent passing of 28% with 2 mm sieve conducted at a texture in situ at ATD =0,7 mm.Binders and additivesFor a AC-BBSG mixture, the following is used:- 35/50 grade pure bitumen in the case of heavy loadings and altitudes lower than500 m, or a 50/70 grade in more typical cases and eventually a 70/100 grade inmountainous zones with harsh climate (categories advised in the StandardsApplication Guide); and- special bitumen with low thermal susceptibility, or a polymer-modified bitumen forspecific loading conditions (ramps, intersections, bus lanes). Adding 0,5% to 0,8%polyethylene serves to improve rutting resistance (in particular for the purpose ofobtaining a Category 3).A AC-BBS (“soft flexible asphalt concrete for low trafficked pavements) mixture is toinclude:- 50/70 or 70/100 paving grade bitumen.For a AC-BBME mix, the following are used:=> 35/50 grade bitumen, potentially combined with additives;=> "hard" bitumen, but not from 10/20 category, whether modified by polymers or not.3.3.2.2 Composition of the granular mixThe initial particle size distribution curves for AC-BBSG, AC- and AC-BBME aregiven in Table 25. It should be pointed out that the AC-BBS mix comprises a widerrange of application thicknesses (4 to 12 cm) than both AC-BBSG and AC-BBME.This difference could lead to targeting a higher percent passing value at 2-mm sieve(capable of reaching 40%).Table 25 – Initial AC-BBSG, AC-BBS and AC-BBME grading curvePercent passingsieve, in mmTypical valuesD = 14 mmTypical valuesD = 10 mmMinimumTargetvalueMaximumMinimumTargetvalue10 78 97Maximum6,3 47 52 58 45 57 684 47 522 25 31 35 27 34 390,063 6,3 6,8 7,2 6,3 6,7 7,2- 91 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -3.3.2.3 Bitumen contentBitumen content at the beginning of this study is taken from Table 26 using themaximum aggregate density equal to 2,65 g/cm 3 or to 2,75 g/cm 3 , or calculated fromthe specific surface area of the mix, the maximum density (MVR) and the richnessmodulus as done in the former French standard. The former external binder contentwith a maximum density of 2,75 g/cm 3 , characteristic of an average French value, isalso mentioned.To complement this input, Appendix C provides the correspondence table betweenexternal and internal binder content, calculated for an identical mass density of2,65 g/cm 3 .Table 26 – Initial BBSG, BBME and BBS richness modulus and binder contentAC10-BBSG,AC10-BBMEAC14-BBSG,AC14-BBMEAC10-BBS1AC10-BBS2AC14-BBS3AC14-BBS4Binder contentB min for 5,5 5,2 5,3 5,7 5,2 5,0ρ = 2,65 g/cm 3Binder contentB min for 5,3 5,0 5,1 5,5 5,0 4,8ρ = 2,75 g/cm 3Typical targetof richnessmodulus K3,5 3,3 3,4 3,7 3,4 3,1External bindercontent TL ext for 5,6 5,3 5,4 5,8 5,3 5,0ρ = 2,75 g/cm 33.3.3 Porous asphalt mixes – PA-BBDrFigure 23: Cross-section of a Porous Asphalt(PA-BBDr)Figure 24: Surface appearance of a PorousAsphalt (PA-BBDr)- 92 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -3.3.3.1 Remarks concerning mix componentsAggregatesThe aggregates consist for the most part of solid rock.Should granite be used, the level of water resistance needs to be verified.The Los Angeles value becomes very important in avoiding compaction-inducedfragmentation.Polish Stone Value, PSV, plays a key role in improving the skid resistanceparameter.The flat coarser aggregates are also exposed to the effects of fragmentation.For each d/D fraction, controlling the tails of the d curve proves determinant toobtaining the desired percentage of voids.Some guidelines call for introducing 1% quicklime in order to incite greateradhesiveness. The use of slaked lime is intended to stiffen the mortar as a means ofavoiding drainage.Binders and additivesThe binder may be either a 50/70 or 35/50 grade pure bitumen or a polymer-modifiedbitumen.With the polymer-modified bitumen, it would be necessary to increase theconcentration by 0,4%.The recommendations on extra binder concentration are not unanimous. Someresearch favors systematic reliance (at a rate of 0,3%).For the water-sensitivity test, the I/C (r/R) ratio is not always an accurate indicator(due to the risk of aggregate fragmentation during the compaction by compression ofspecimens as in a Duriez test).Additives are primarily intended to lower the risk of drainage. Fibers (cellulose, glassor rock) are introduced at a rate of 0,3%.3.3.3.2 Composition of the granular mixThe initial PA-BBDr particle size distribution curves are specified in Table 27. Thedrainage capacity of the mix is affected by the percentage passing the 2-mm sieve.Table 27 – Initial PA-BBDr grading curveSieve sizePorousAsphalt(PA-BBDr)Category 1Category 2D,in mmGap-gradedfraction6,3 mm(%)10 mm(%)2 mm(%)0,063 mm(%)0/10 2/6 13 13 ± 2 3,50/6 2/4 10 10 to 13 3,50/10 2/6 8 8 ± 1 3,56/10 2/4 5 5 ± 1 3,5- 93 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -3.3.3.3 Bitumen contentBitumen content at the beginning of this study is taken from Table 28 using themaximum aggregate density equal to 2,65 g/cm 3 or to 2,75 g/cm 3 , or calculated fromthe specific surface area of the mix, the maximum density (MVR) and the richnessmodulus as done in the former French standard. The former external binder contentwith a maximum density of 2,75 g/cm 3 , characteristic of an average French value, isalso mentioned.To complement this input, Appendix C provides the correspondence table betweenexternal and internal binder content, calculated for an identical mass density of2,65 g/cm 3 .- 94 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -Table 28 – Initial Porous Asphalt (PA-BBDr) binder content (Richness modulus)PA10-BBDr1(%)Paving grade bitumen: 4,4 to 4,8Binder content B int for anρ = 2,65 g/cm 3 Rubber: 5,6 to 6,0aggregate mass densityFibers: 5,1 to 5,5Binder content B int for an Paving grade bitumen: 4,2 to 4,6aggregate mass densityFibers: 4,9 to 5,2ρ = 2,75 g/cm 3 Rubber: 5,3 to 5,7Category 1PA6-BBDr1(%)Paving grade bitumen: 4,6 to4,9Fibers: 5,2 to 5,8Rubber: 5,9 to 6,15Paving grade bitumen: 4,4 to4,7Fibers: 4,9 to 5,5Rubber: 5,6 to 5,8Richness Modulus K 3,3 3,4Binder content TL ext for a Paving grade bitumen: 4,4 to 4,8granular mix mass densityFibers: 5,1 to 5,6ρ = 2,75 g/cm 3 Rubber: 5,7 to 6,1Paving grade bitumen: 4,6 to 5Fibers: 5,3 to 5,9Rubber: 6 to 6,3PA10-BBDr2(%)Paving grade bitumen: 4,2 to 4,6Binder content B int for anρ = 2,65 g/cm 3 Rubber: 5,3 to 5,7aggregate mass densityFibers: 4,9 to 5,2Category 2PA6-BBDr2(%)Paving grade bitumen: 4,4 to4,7Fibers: 5,2 to 5,8Rubber: 5,9 to 6,15K 3,2 3,13.3.4 Thin asphalt mixes – AC-BBM, BBTM and mixes for UTLAC (BBUM)Figure 25: Cross-section of a Thin LayerAsphalt Concrete (AC-BBM)Figure 26: Surface appearance of a Thin LayerAsphalt Concrete (AC-BBM)- 95 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -3.3.4.1 Remarks concerning mix componentsAggregatesThe observations forwarded above for the porous asphalt (PA-BBDr) mixes wouldalso apply Thin Layer Asphalt Concrete (AC-BBM), Very Thin Layer AsphaltConcrete (BBTM) and Ultra-Thin Layer Asphalt Concrete (UTLAC or BBUM) families.By lowering the percent passing at 2 mm, porosity increases as does the meantexture depth (MTD).Binders and additivesThe binder may be either a 50/70 or 35/50 grade pure bitumen or a polymer-modifiedbitumen.The Thin Layer Asphalt Concrete (AC-BBM) family of mixes often contains purebitumen.When rutting resistance is targeted, it is advised to select a bitumen with enhancedthermal susceptibility and to add polyethylene or use a modified binder.BBTM mixes are produced with either pure or modified bitumen and without providingobjective selection criteria (the texture loss test, which had been listed in the previousversion of the standard, did not offer distinctive insight on this particular point).The use of cellulose or glass fibers in BBTM mixes is intended to improve the(empirical) quality of the mortar.3.3.4.2 Composition of the granular mixThe initial particle size distribution curves for Thin Layer Asphalt Concrete (AC-BBM)and BBTM are provided in Table 29 below. The texture and open appearance ofthese mixes are influenced by the percent passing the 2-mm sieve.Types B and C of the AC-BBM family are rarely applied, yet they adapt well to flexiblepavements submitted to light traffic loads.- 96 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -DTable 29 – Initial AC-BBM and BBTM grading curveSieve percent passingGap-gradedfraction 14 10 6,3 4 2 0,063AC-BBMA 10 2/6 97 35 30 - 32 6,5 - 7,2Not advised ⇒ 14 2/10 97 35 35 7,2AC-BBMA 14 4/10 97 35 35 7,2AC-BBMA 14 2/6 97 67 35 34 7,2AC-BBMB 10 Continuous 97 53 53 38 10AC-BBMB 14 Continuous 97 75 50 50 35 10AC-BBMC 10 Continuous 97 53 53 38 7,2BBTM,Category DBBTM,Category A10 2/6 30 25 - 35 5,5 to 6,56 2/4 30 28 - 35 7,0 to 8,0BBTM, 10 2/6 25 18 - 25 5,0 to 6,0Category B 6 2/4 25 20 - 25 5,0 to 6,0Sieve percent passingGap-gradedfraction 14 10 6,3 4 2 0,063BBTM, 10 Continuous 30 25 - 35 7,0 à 7,5Category A 6 Continuous 30 30 - 35 7,0 à 8,0BBTM, 10 Continuous 25 18 - 25 5,0 à 6,0Category B 6 Continuous 25 20 - 25 5,0 à 6,03.3.4.3 Bitumen contentBitumen content to start the mix design, is calculated from the specific surface areaof the mix, the maximum density (MVR) value and the minimum richness modulus.Table 30 below presents internal binder content (according to EN Standard) with amaximum density (MVR) of aggregate 2,65 g/cm 3 for AC-BBM, BBTM and mixes forUTLAC (BBUM); the external binder content (application according to former FrenchStandard) with a maximum density (MVR) of aggregate of 2,75 g/cm 3 , is alsomentioned.- 97 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -Table 30 – Initial AC-BBM, BBTM and mixes for UTLAC (BBUM) binder contentAC10-BBM AAC14-BBM ABBTM10Class A or DBBTM6Class ABBTM10Class BBBTM6Class BBinder content B int fora granular mix massdensityρ = 2,65 g/cm 3 5,4 5,2 5,6 – 6,05 6,05 – 6,5 4,5 – 5,4 5,4Binder content TL extfor a granular mixmass densityρ = 2,75 g/cm 3 5,5 5,3 5,7 – 6,2 6,2 – 6,7 4,5 – 5,5 5,50/10 UTLAC (BBUM) 0/6 UTLAC (BBUM)Binder content B int fora maximum aggregatedensity ρ = 2,65 g/cm 3 4,95 – 5,7 5,7 – 6,2Binder content TL extfor a maximumaggregate densityρ = 2,75 g/cm 3 5 – 5,8 5,8 – 6,43.3.5 Stone Mastic Asphalt - SMAFigure 27: Cross-section of an SMA(Stone Mastic Asphalt)Figure 28: Surface appearance of an SMA(Stone Mastic Asphalt)- 98 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -3.3.5.1 Remarks concerning mix componentsBinders and admixturesSMA generally contain fibers. It should be remarked that with the inclusion of fibers,the mix design that yields bitumen content on the basis of richness modulus is notconsidered valid.3.3.5.2 Composition of the granular mixThe initial particle size distribution curve for SMA is indicated in Table 31 below.Table 31 – Initial SMA grading curveD 10 8 6.3 4 2 0.063SMA10 92 57 - 62 39 - 44 30 - 348 100 96 73 4025(20 to 35)27(20 to 40)11(5 to 13)12(5 to 14)3.3.5.3 Binder content and fiber contentThe bitumen content at the beginning of this study is shown in Table 32 below,calculated in two ways:- internal binder content (according to EN Standard) with a maximum density(MVR) of aggregate equal to 2,65 g/cm 3 ;and- for information, external binder content (application according to formerFrench Standard) with a maximum density (MVR) of aggregate of 2,75 g/cm 3 ,characteristic of an average French value;To complement this input, Appendix C provides the correspondence table betweenexternal and internal binder content, calculated for an identical mass density of2,65 g/cm 3 .Table 32 – Initial SMA binder contentSMA 10 SMA 8Binder content TL int for amaximum aggregate6,8%densitywith 0,3% cellulose fibersρ = 2,65 g/cm 3Binder content TL ext for amaximum aggregate7%densitywith 0,3% cellulose fibersρ = 2,75 g/cm 37,2%with 0,3% cellulose fibers7,55%with 0,3% cellulose fibers3.4 Composition adjustmentsBased on the standard grading curves defined for each material, the mix designerseeks to obtain the percentage of voids specified for each product (see Table 9). For- 99 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -this step, the mix is typically submitted to the Gyratory Compactor test (or anotherdesignated test). If the expected result is not the one ultimately obtained, the mixdesigner must modify the composition, which requires understanding the effect ofcomposition variables.3.4.1 Effect of mix variables (general remarks)The mechanical characteristics of the mix stem from the combined effect of internalfriction on the granular skeleton, binder content and binder characteristics (includingthe additives eventually introduced).3.4.2 Effect of dimension DIf D were to be increased, the richness modulus (and thus binder content) wouldhave to drop.With all other parameters held unchanged, by increasing D, the percentage of voidsin the mix decreases.As the D value of the mix rises, it becomes easier to obtain a stable material, yetattention must then be paid to the risk of segregation during placement.– Example –A AC10-BBSG mix with 5,6% bitumen is equivalent to a AC14-BBSG with 5,4% bitumen.A AC10-BBSG with 5,6% bitumen leads to a percentage of voids at 60 gyrations V60 = 9%, while aAC14-BBSG with 5,4% yields a characteristic percentage of voids at 80 gyrations V80 = 4%.3.4.3 Effect of granular proportionsWith greater granular fractions, mix design setting becomes facilitated.For a 0/D mix with 10 mm < D < 20 mm, the percent passing at 2 mm can displayone of the four following cases:• > 35% percent passing at 2 mm very high curve: mortar content is in excesswithin the granular skeleton and stability relies solely upon the mortar.• 30 to 35% percent passing at 2 mm high curve: the mortar fills nearly all interaggregatespace. The mortar plays a key role in overall mix characteristics.• 25 to 30% percent passing at 2 mm average curve: coarsely-graded design.Mortar influence is attenuated due to effect of the granular skeleton.• < 25% percent passing at 2 mm low curve: the mortar exerts a secondaryinfluence, with mix stability obtained by means of inter-aggregate setting.3.4.4 DiscontinuityA discontinuity (gap-grading) within the particle size distribution curve leads to anincrease in workability along with a drop in percentage of voids, although the ruttingrisk rises as a result.- 100 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -– Example –A AC14-BBSG or a AC14-BBM with a continuous curve yields a rut depth of 3 mm at 30000 cycles.The rut extends to 4 mm with a 2/6 discontinuity and to 10 mm with a 2/10 discontinuity.Should the material be used as a thick layer, it would be preferable to apply a gapgradedcurve with a relatively low threshold, e.g. 25% at 2 mm.3.4.5 Incorporation of rounded particle aggregateThe inclusion of rounded particles, generally limited to 10% for wearing courses,serves to increase mix workability while reducing the percentage of voids. On theother hand, the risk of rutting naturally rises quite considerably as a consequence.This type of mix formulation is not be used on roads submitted to heavy traffic loads.For AC-EME or AC-BBME however, blunt-edged materials, and in particular fineaggregate with totally rounded particles, may be used to enhance compacity, withbinder stiffness serving to reduce the risks of rutting. Yet when employing such anapproach on surface materials, the durability over time may be compromised.3.4.6 Percentage of fillersFillers, in combination with bitumen, make it possible to fill the inter-granular voids.As total filler percentage increases, the percentage of voids in the mix will drop, butthe mastic will harden. The optimal value lies between 6,5% and 7,5% for averagecurves and typical bitumen contents.3.4.7 Percentage of bitumenBitumen, when combined with fillers, plays the role of lubricant for the granularskeleton and thus enables compacting the material. Beyond an optimal content, itsfunction is limited to filling voids in the granular skeleton. As the percentage ofbitumen increases at low bitumen content levels, the stiffness modulus rises as well;whereas with higher bitumen content, this modulus tends to fall.As the percentage of bitumen increases, the inter-granular mastic film becomesdenser and thicker, which makes for improved fatigue and water resistance, with thedownside being that rutting resistance decreases.These trends have been laid out under very general conditions. In practice, certainmix component characteristics can modify expected behavior. As an example, itwould be necessary to incorporate the effect of absorbent materials (porousaggregates, fibers).3.5 Gyratory Compactor compactibility study3.5.1 General remarksThe test is conducted on a composition (test interpreted in isolation) or on anexperimental design (2 or 3 different granular compositions) containing, for example,a 5% deviation in the fine aggregate concentration.- 101 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -This test is to be interpreted in two ways; first, it seeks to verify the type testingcriteria (v% at 60, 80, 100… gyrations as specified vs. the thickness of the layerunder consideration) in comparison with the standard, should one exist.Secondly, the test is intended to make use of the entire set of data available topredict one behavioral aspect of the mix or another.The Gyratory Compactor test is quite sensitive to: granular composition, including thefines fraction; angularity of the mineral skeleton; and binder content.Upon completion of the Gyratory Compactor tests, the mix designer must be able tointroduce enough elements to establish both the particle size distribution curve andbinder content.The primary parameters to be interpreted are the following:‣ percentage of voids vs. number of gyrations;‣ percentage of voids at a given number of gyrations;‣ percentage of voids at 10 gyrations;‣ percentage of voids at 1 gyration;‣ slope K1; and‣ pseudo-maximum shear stress.3.5.2 Percentage of voids vs. number of gyrationsThe evolution in compaction using the gyratory compactor, v% = f(ng), was studied atthe same time on a full-scale compaction bench [Moutier, 1977; Bulletin de liaisonLPC, Special Issue V, p. 173-180]. This compaction bench contained an axle capableof being loaded up to 50 kN per wheel, with tire pressure varying from 0,3 to0,9 MPa. Production was routed through a reduced-scale mixing plant and placementhandled by a small finisher.The experimental design focused on three thickness ranges: 4 cm, 8 cm and 12 cm.For each of these ranges, three different mix designs were introduced:– in 4-cm thickness: AC10- BBM with rounded fine aggregate, AC14-BBM (2/10 and 4/6 gap-graded) (solid mineral aggregates N);– in 8-cm thickness: "coarse" AC14-BBSG; "semi-coarse" AC14-BBSG, discontinuous AC14-BBSG (solid mineral aggregates N); and– in 12-cm thickness: AC20-GB2 with aggregates from three differentsolid rock origins: microdiorite, quartzite and alluvial deposits.Experience has shown that percentage of void trend curves vs. number of gyrationsand vs. number of compactor passes are quite similar. On the v%= f(ng) andv%=f(np) graphs, with a semi-logarithmic scale for the number of gyrations orcompactor passes, the evolution is nearly linear.- 102 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -A sigmoid model (S-shaped) was applied to the v%=f(ng) curve in order to deduce extreme clampingbehavior at a very high number of gyrations (curve asymptote). This model is relevant for the range ofmaterials tested (AC-BBSG, HRA, AC-BBM). The compacity of the granular skeleton submitted tohigh energy levels tends to a limit, denoted C∞; this compacity value is greater than those obtained attypical gyration thresholds (< 200) and suggests that even for very angular mixes, an additional"clamping potential" remains over and above current specifications. Such potential can be realizedduring exceptional climatic or traffic conditions.Modeling of Gyratory Compactor results - Assessment of ultimate compaction threshold,F. Moutier, Eurasphalt & Eurobitume Conference '963.5.3 Percentage of voids at a given number of gyrationsComparing the percentage of voids measured on specimens generated from thestudied plates for a "standard" compaction mode (approximately 16 passes) with thatderived using the gyratory compactor by direct geometric measurement hasdemonstrated that: for mixes applied in 4-cm thickness, the correspondingpercentage of voids was obtained at 40 gyrations; and for 8-cm thick mixes, 80gyrations were required to reach this void level. Experimentation conducted on 12-cmthick material samples proved less conclusive. The 40-gyration relationship for the 4-cm material (AC-BBM and PA-BBDr ranges) and evaluation at 80 gyrations formaterials spread over 8 cm (AC14-BBSG or AC14-BBME) initiated adoption of theFrench specifications. Following a few extra experimental findings, this relation wasgeneralized: 25 gyrations for 2,5-cm thick BBTM; 60 gyrations for AC10-BBSG orAC10-BBME spread 6 cm thick; 100 gyrations for AC14-GB or AC14-EME ( highmodulus mixes) applied approximately 10 cm thick; 120 gyrations for AC20-GB orAC20-EME applied approximately 12 cm thick. These percentage of void ranges,associated with gyration number vs. layer thickness, have become laboratoryspecifications, aimed at predicting the percentage of voids attained on the jobsite.The predictive capacity of the percentage of voids parameter at n gyrations had beenanalyzed as part of a survey entitled: "Gyratory compactor testing assessment" withinthe LPC research network [Ballie, Delorme, Hiernaux and Moutier, Bulletin de liaisonLPC, Issue no. 170]; this work showed that the value identified in the laboratorytended to be somewhat pessimistic for the Grave-Bitume AC-GB and AC14-BBSG,evenly valued for AC10-BBSG and more optimistic for thinner mixes. These relationsdepend on trends tied to: material mix design (e.g. cessation of the use of roundedmaterials), mix production mode (drum mixers), and type of spreading andcompaction (vibratory compactors). Such factors need to be incorporated wheneverthe value targeted for a jobsite is deduced on the basis of a laboratory-determinedpercentage of voids.A study on crushed bituminous aggregate, high modulus mixtures and semi-coarsebituminous concretes has been carried out (see Section 4.1) in order to verify thecorrespondence between the percentage of voids measured: on laboratory materials(representative of worksite conditions), on materials extracted from onsite mixingplants using a mobile gyratory compactor, and onsite by means of gammadensitometers.With the exception of one site where production uncertainties led tounder-compaction, the average results obtained at each stage were for the most partsimilar (maximum deviation: 1,4%).- 103 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -3.5.4 Percentage of voids at 10 gyrations: v 10The percentage of voids at 10 gyrations represents the state of the materialsubmitted to very weak energy. The kind of mix that when exposed to such weakenergy yields a low percentage of voids would actually display excessive workability;it is likely that this result stems from weak internal friction of the granular skeleton,wherein lies the potential risk among more ordinary mixes (AC-BBSG, AC-GB, etc.)of offering only limited resistance to rutting. This risk gets taken into account in thespecifications on certain products, whose threshold has been set lower (9% to 14%).Such a criterion was selected within the scope of EN standards, yet due to itsempirical relation with rutting resistance cannot be imposed at the same time(overspecification).3.5.5 Percentage of voids at 1 gyration: v 1v 1denotes the percentage of voids calculated at one gyration (or C 1 the compacity atone gyration) in accordance with the equation model set forth in the EN 12697-10):v% = v 1- K1 ln ( ng )C = C K ln ngor ( )% + 1 10v 11 K 1 20200ngThe model is then adjusted with respect to a regression line for points (v, ln ( ng ) ) or(C, ln ( ng ) ) lying between 20 gyrations and 200 gyrations. V% is computed byconsidering that compaction using the Gyratory Compactor is linear as a function ofthe logarithm of the number of gyrations.The percentage of voids at 1 gyration also serves as a rutting resistance indicator (forthe same reasons as for v 10 ). The 20% threshold (AC-GB, AC-BBSG) seems toprovide a satisfactory estimation.3.5.6 Slope K 1The slope K 1in the model v% = v 1- K1 ln ( ng ) is sometimes referred to as the mixworkability indicator.Its value is more heavily correlated with the upper sieve size D of the mix. Shouldbitumen content vary over narrow ranges, K 1would stay constant for a given granularskeleton. On the other hand, K 1varies whenever the fines content varies.- 104 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -Granular compacity does not vary any further for bitumen contentsabove 4%. An increase in bitumen content is equivalent to filling theinter-granular voids.For a binder content variation of δTL, compacity C 1 becomes C 2 , i.e.:C2≈ C ×1MVR× δTL× 1001( 100 +)(100 + TL ) x 1,03(The variation of maximum density (MVR) has been neglected herein.)3.5.7 Pseudo shear stress τThe pseudo shear stress τ is defined as the force necessary to straighten thespecimen submitted to gyratory compaction at a small internal angle (0,82°).F1× d1τ is defined by the following relationship: τ = ;h × SF 1 is the force necessary to maintain the Gyratory Compactorangle, expressed in Newtons;d 1 is the distance that force F 1 acts with respect to the specimenaxis, in millimeters;h is the specimen height, in millimeters; andS is the surface area of the specimen base.On the LPC gyratory compactors of types 1 and 2, τ ≅ 0,01 (in MPa).hThe evolution in τ has been tracked vs. percentage of voids v%. At the maximum τvalue, τ max , the value of v%(τ max ) corresponding with this maximum is obtained.1F 1ττ max% Voidsv % (τ max )- 105 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -The variations in τ as a function of v% depend on the type of mix. As an example, forAC-EME or BBTM, the curves exhibit the following shapes:ττ maxAC-EMEτBBTMτ max% voidsv % (τ max )v % (τ max )⎯ v%(τ max ): The percentage of voids corresponding to the value of τ max constitutes alower bound of the mix design application range (i.e. the critical percentage ofvoids). Beyond this limit, the mix loses its stability (presence of rutting risk).⎯ τ might be correlated with v fb < 65% or 75%.3.5.8 Test precisionPercentage of voids at a fixed number of gyrations:Repeatability: r = 0,95Reproducibility: R = 1,38r and R represent the critical distance separating two test results under conditions ofeither repeatability (same laboratory, same sample, same operator, short timeinterval) or reproducibility (with different laboratory and operator). Should thedistance between any two results lie below this critical distance, results could not beconsidered as distinct.3.5.9 Correction of mix compositionThe effects of mix composition factors on the Gyratory Compactor test results werestudied within the framework of an experimental design that includes upper sieve sizeof the mix, factor D, the bitumen percentage, factor B, the percentage of fines factorF and the compacity (or void content) factor C; the primary set of results of thisexperimental study DBFC will be presented next.- 106 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -Example – Impact of mix design factors on Gyratory compactor test results(solid mineral aggregates N)Experimental plan DBFC: Impact of factors D (mm), binder content B (%), filler content F (%) onthe mix compacity:D, B, F have a significant effect on C80D, B have a significant effect on C1D, F have a significant effect on C180,00Effect of binder content B on C178,0076,00C1 (%)74,0072,0070,0068,004 6 8binder content (%)78,00effect of D on C177,0076,00C1 (%)75,0074,0073,0072,0071,006 8 10 12 14 16 18 20 22D mm- 107 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -C80 (%)878786868585848483838282effect of filler content F on C804 8 12Filler content (%)89effect of D on C80C80 (%)88878685848382816 8 10 12 14 16 18 20 22D mm- 108 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -effect of binder content B on C80C80 (%)908886848280784 6 8Binder content (%)These composition parameter effects were examined on "test" mixes for purposes ofthe experimental design, with mix compositions not always corresponding to thoseactually employed on road-building sites. While the experimental design has servedto confirm major well-known trends practiced by mix designers, testers werequestioned about their own experience, and this step gave rise to the contents shownin Table 33:Table 33 - Composition effect on Gyratory Compactor test resultsTrends in composition parameter effects on Gyratory Compactor test resultsParameter Effect (%v ng ) ObservationsBitumen content – 0,25 + 0,5 to + 0,6 See water resistanceBitumen content + 0,25 - 0,5 to – 0,6 See rutting resistanceFines content + 1 - 1,7 to – 0,5Fine aggregate volume + 10% - 1Passing the 2-mm sieve + 5% - 1 to – 1,5%2/4 discontinuity (at a constant fine aggregate %) - 12/6 discontinuity (at a constant fine aggregate %) - 34/10 discontinuityMastic volume 16% -> 23% + 4%+ 10% rounded fine aggregate - 1,5 to - 2 Potential rutting- 109 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -Table 34 - Composition adjustment in order to correct Gyratory Compactor resultsAdjustments to the composition to ensure thatGyratory Compactor voids are positioned within the target windowMuch lower than thetarget % (by > 5%)Lower than thetarget % (by 3%)Above thetarget % (by 3%)Considerably abovethe target % (by > 5%)decrease the %passing the 2-mm sieveby ~ 5 points andincrease the 2/6,3fractiondecrease thebitumen %anddecrease the % of totalfines by 1,5% to 2,5%decrease the 2/6,3fraction on the order of10% and increase the6,3/10 fractionincrease the % passingthe 2-mm sieve by~ 5 points anddecrease the 2/6,3fractionintroduce ground fineaggregate at a level of10% or 15% (focus onrutting resistance)orrounded fine aggregateat a level of 10% (focuson rutting resistance)3.6 Mix performance3.6.1 Resistance to permanent deformation on the LPC Wheel Tracking Tester3.6.1.1 PurposeThe objective herein is to verify that the mix actually exhibits the behavior expectedduring the compactibility study phase. The effect of both binder type and admixturesis to be taken into account as well.The test is conducted on 2 plates at a required level of compacity and leads either toreaching the specified level of compacity, thus making the results directlyinterpretable, or to repeating a 2-plate series at a compacity level such that the twovalues obtained frame the intended result. If the new series lies within the prescribedrange, the rut depth can be interpreted directly, whereas if the percentage of voidslies outside this range, the wheel tracking test result at the target value is to be foundby means of linear interpolation.Example: For a AC-BBSG, the interval specified in the standard is 5% to 8% voids.If the first attempt leads to 3% voids, the second will aim for a position around 7%. Ifa figure less than 8% is actually obtained, the result may be determined directly.Otherwise, with 10% voids for example, the following operation is performed:Linear interpolation between the rut depth at 10% voids (i.e. 7%) and the depthmeasured at 3% voids, i.e. 12%. The interpolated result at 6,5% voids amountsto 9,5%.- 110 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -Rut depth, %129,575Interpolated valueTrend curve estimatedfrom the rut depthSpecified range10 86,553slab voids %The interpolated value obtained using this method is "pessimistic" from a safetystandpoint in comparison with the experimental value, which lies close to 5% in theabove example.The result must satisfy a rut depth threshold (with respect to plate thickness), i.e. 5%,7,5% or 10% at a given number of cycles: 3000, 10000, 30000.Remarks:In order to preserve a safety margin, the test may be conducted for a binder contentincreased by 0,25% or with a "softer" grade bitumen than that of the prescribedbitumen.Generally speaking, the percentage of voids estimated from a test plate corresponds:- for weak compaction low in percentage of voids with the Gyratory Compactor at 40gyrations,- for strong compaction high in percentage of voids at 120 gyrations. One deviationwith respect to this estimation may be the indicator of a workable or, alternatively,rough mix.Another practice consists of adopting 10% voids for weak compaction and 5% forstrong compaction with ordinary mixes.3.6.1.2 Results interpretationRut percentageLess than 10% at 30000 cycles constitutes, for mix designs with a continuous grainsize distribution, a widely-recognized limit to indicate that the mix is not at risk ofrutting under harsh use conditions.Less than 5% at 30000 cycles constitutes a widely-recognized limit to indicate thatthe mix is not at risk of rutting under very harsh use conditions.An intermediate category at 7,5% was introduced for several mix products (AC-BBSG, AC-EME, AC-BBME).- 111 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -Under exceptional loading conditions, a test can be performed at 65°C, with a 6-kNvertical force, and ultimately in including a metallic wrapping. No reference data arecurrently available on any such test.Curve shapeWith some modified binders, the lg(P%) = lg(number of cycles) curve suddenly veersat around the 3000-cycle mark; one plausible explanation for this phenomenon wassought, with the conclusion being that localized parasitic heating could constitute thecause.Based on experimental data, it is possible to identify the parameters A and b of adeformation law of the following form:Y = A (N/1000) bThis approach no longer appears in the EN standard.3.6.1.3 Special case of the "mechanical stability" testFor very thin layer asphalt concretes BBTM, a "mechanical stability" test may becarried out by employing the rutting test operating protocol. This test is not of therutting type per se, but instead is intended to characterize the capacity of the mix to"close" and spread smoothly in rolling strips. The rut depth criteria can thus be statedas: 3000 cycles = 15% (0/10 BBTM) and = 20% (0/10 BBTM).3.6.1.4 Influential parametersTable 35 lists the composition parameters capable of influencing the rutting testresult and their effects. Table 36 then summarizes the advice of practitioners forraising rutting resistance.- 112 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -Table 35- Effects of mix design factors on % ruttingExample of effect of composition parameters on rutting test resultsParameter % rutting ObservationsBitumen content: 0,2% increaseBitumen content: 0,2% decreaseFines content: 0,8% increaseAt 3000 cycles, the rut depth expandsfrom 5,5% to 9,6%At 3000 cycles, the rut depth declinesfrom 5,5% to 3,9%No noteworthy effectBitumen gradeTransition from70/100 gradeto 35/50 gradeAt 10000 cycles, the rut depth dropsfrom 5,5% to 3,2%7°C rise in T R&BRutting resistance increases by a set of tencyclesAt 10000 cycles, the rut depth of a AC-BBSGis scaled back:Strong rise inangularity:Ic 30 to Rc 2CASE 1 from 14% to 10%CASE 2 from 12,3% to 7,5%AngularitySmall rise inangularity:Ic 80 to Ic 100(Formerapproach ofangularity =>C 90/1 to C 95/1 )CASE 3 from 10,5% to 9,8%CASE 4 from 12% to 6,2%at 10000 cycles, the rut depth of a crushedbituminous aggregate declines:CASE 1 from 5,2% to 2,3%CASE 2 from 6,3% to 3%The compacityeffect alters theresult.+ 10% roundedfine aggregateAt just 1000 cycles, the rut depth jumps from3% to 10%.Replacementof crushedfines by groundfinesFor a % passing the 2-mm sieve on the orderof 33%, rut depth increases from 7,5% at30000 cycles to 10% at 3000 cycles.Table 36 - Practitioners' advice - Enhancing rutting resistanceWheel tracking - Rut depthGreater than the target value > 2% above target value Observations− "Indent" the curve− Use bitumen with a ring and− Lower binder contentball temperature and applyadmixtures, PE, etc.− Use bitumen with a higher ring andball temperature− Use admixtures− Use a special bitumen withgreater thermal susceptibility− Change the fine aggregateBeware of the risk of topdowncracking, ifapplicable (hard grade +low bitumen content)- 113 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -3.6.2 The Duriez test (Method B of EN 12697-12)The Duriez test procedure is described in part B of EN 12697-12 ITSR. In thisstandard, the specimens may be compacted using several methods (gyratory,impact, core…). The results considered in this clause are obtained with specimenscompacted in compression by application during (300 ± 5)s of 60 kN ± 0,5 % forspecimens of which diameter is less than 100 mm or 180 kN ± 0,5 % for otherdimensions.3.6.2.1 PurposeThis test is intended to verify water resistance. It does however serve to approximatethe mechanical characteristics and percentage of void values submitted to staticcompaction.3.6.2.2 InterpretationI/C (r/R) valueThe typical values of I/C (r/R) lie between 0,65 and 1,0.Example for porphyries from Boulouris (south of France)This quarry mines an eruptive deposit principally characterized by the very strong CPAreading (> 0,55), corresponding to a PSV of 57; the cleanliness of the fine aggregate complies withthe "a" category: Vbta lies on the order of 1 g/100g, i.e. for an MBF on the order of 1000 g/kg.Despite these findings, it was proven that the use of fine aggregate and, in some instances, coarseaggregate lead to generally noncompliant water resistance values, as shown in the followingexamples:Mix designBinder (% out of the Additive I/C (r/R)AC20-GB all porphyryi i )5,5% of 35/50 / 0,53AC20-GB all porphyry 6,0% of 35/50 / 0,73AC10-BBSG 5,9% of 35/50 / 0,71Fine alluvial aggregate,coarse porphyry aggregateBBTM66,2% of 35/50 / 0,796,6% of 13/40 Styrelf / 0,687% of 13/40 Styrelf / 0,72Fine alluvial aggregate7% of 13/40 Styrelf0,3% CecabaseS 240 PF0,784/6 porphyry 7% of 13/40 Styrelf0,6% CecabaseS 240 PF0,80I/C (r/R) ratio values greater than 1 are to be correlated with problems of bitumenabsorption by aggregates.Using mixes rich in coarse aggregate, e.g. drainage mixes, aggregate failures mayarise during specimen production. The I/C (r/R) value is thus less than 0,8.- 114 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -For some granite materials, water resistance must still be verified.Compressive strength I/CTable 37 - Typical I/C values (in MPa)BitumencategoryAC-GB AC-EME BBTMPA-BBDrAC-BBMEAC-BBSGAC-BBM50/70 6 to 9 7 to 9 (*) 5,1 to 7,135/50 9 to 14 6 to 10 2 to 4< 25 12 to 216 to 14(typical: 9-10)6,6 to 12,1(*) Mix designs composed of pelite coarse aggregate and limestone fine aggregate have yielded a compressive strength of 12,1 MPa.Percentage of voids:This parameter is to be compared with the percentage of voids using the GyratoryCompactor for n gyrations. On the AC-BBSG material, the percentage of voids lieson the same order of magnitude. If the level of deviation amounts to 3% or 4%, thematerial is said to be "frictional".Percentage of imbibition:This parameter is used in evaluating the swelling nature of the material and has beendefined by:M: mass of the dry specimen,M j+1 : specimen mass after degassing (1 hour without immersion+ 2 hours with immersion),M j+k : specimen mass after k days of immersion.Mj+ k − MThe percentage of imbibition is defined using: W j+k = * 100MThreshold value: ===> 2%The swelling (increase in specimen volume) goes hand in hand with low I/C (r/R)ratio values, through observations on materials such as polluted limestone or watersensitivesolid rocks.Adjustment of resultsTable 38 - Practitioners' advice - Duriez test results adjustmentBelow the targeted valueI/C ratio− bitumen enhancer within the mass (extra 0,3%-0,6%compared with the original bitumen)− use of fines activated by 20% quicklime or slakedlime− increased richness modulus (with decrease in the% passing the 2-mm sieve)− introduction of a harder grade bitumen− higher compacity through a drop in the 2/6 fractionDuriezMuch lower than the targeted value− contribution of 1% quicklime or slakedlime− replacement of all or part of the fineaggregate proportion by fine aggregatefrom another origin- 115 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -Remark:Stability of the additive (enhancer) within the hot binder:Example of Cecabase S240 PF on a 0/6 BBTM material: I/C (r/R) = 0.72; with 0.3%enhancer held 48 hours at the production temperature, the I/C (r/R) ratio remainsroughly the same: 0,75. With 0,6% additive (enhancer) and under this same set ofconditions, the I/C (r/R) ratio equals 0,8.3.6.3 Stiffness modulus3.6.3.1 General commentsDetermination of the stiffness modulus requires longer tests that typically extendbeyond the mix design context. For certain materials (e.g. AC-EME), it nonethelessproves necessary to know the mix stiffness modulus in order to ensure thatspecifications are being met.Depending on possibilities available in the laboratory, various stages of experimentaldesigns can be developed using either the direct tensile test or the complex modulustest.⎯ Complex modulus:It is possible to derive a rough design by directly conducting a test at 15°C /10 Hz.⎯ Modulus determination test in direct tension (MAER):Modulus at 15°C and 0,02 sec: this modulus value is greater than or equal to thecomplex modulus at 15°C / 10 Hz.For AC-EME in particular, the direct tensile modulus often exceeds the complexmodulus.Regarding the contour of the index curves at a given temperature, in the absence ofexperimental values, the time-temperature equivalence principle may be appliedalong with the following relation:∆H1 1a T (T,Ts) = exp [ ( − )]R T Ts∆H: in the vicinity of 50 kcal/moleR: perfect gas constant = 8,353.6.3.2 Effect of mix design factorsThe variations in stiffness modulus vs. compacity variation ∆C may be approximatedby means of the following equation where Tl ext is the binder content “out of the mix”:∆E = (2,000 – 310 TL ext) ∆CTL ext(Equation established with solid mineral aggregates N and a 40/50 bitumen)The bitumen content effect may then be approximated using this equation:∆E = (18,000 – 3,700 TL ext) ∆TL ext- 116 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -(Equation established with solid mineral aggregates N and a 40/50 bitumen)Example: Impact of mix design factors on the direct tensile modulus9,50Effect of F on the modulus 10°C,0,02smodulus 10°C,0,02s9,008,508,007,507,006,506,004 5 6 7 8 9 10 11 12Filler content3.6.3.3 Loss of linearityThe loss of linearity Γ, as defined in the test standard, is determined for a 30-secondloading time and 0°C temperature.Γ is a first-loading damage indicator and tends to be correlated with microcrackformation in the mix; for this reason, a correlation with fatigue resistance could bederived (see Section 3.6.4).With stiff materials, such as AC-EME, material fractures are observed prior toreaching the 500 µdef threshold.3.6.3.4 Direct tensile modulus - complex modulus equivalence relationTheoretical formulae have been developed to correlate modulus values E(θ,t)and E(θ,f).At 10°C or 15°C, the modulus values for a 10-Hz frequency and 0,02-sec loadingtime may be considered as equivalent.This equivalence has been experimentally verified to a large extent. Deviations havehowever been detected on certain materials [up to 4000 MPa].Example of experimental relationship between E 15°C 10Hz and E 15°C 0.02 s :E0,989×E150. 0215° C10Hz=° C s−15,168R2=0 ,974[RILEM '97, Lyon - p. 225]- 117 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -3.6.3.5 Estimations of mix modulus valuesThe stiffness modulus of the mix may be estimated by means of empirical equationsthrough the introduction of a range of approximations.Ugé's method:2( 5,68 Vg 0,2135 )−38 + 10vgIg Sm =+[Bitumen and asphalt mixes, BL.NSV]For bitumen samples with a stiffness modulus value S b (expressed in MPa) eithermeasured or determined using the Van Der Poel abacus, the mix modulus can beestimated by employing the nomograph shown in Figure 29 with respect to bitumenvolume V b and aggregate volume V G .- 118 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -Figure 29: Nomograph for calculating mix stiffness modulus values- 119 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -The stiffness modulus values generated using this method may deviate fromexperimental values by a factor of 2.Shell method: Estimation of the bitumen modulus (Péné + TBA); computation of themix modulus based on granular compacity and loading time or frequency).The standard modulus calculation formula is given by:Sm⎡= S⎣2,5Cvb ⎢1 + × , in MPa.n 1−Cv⎥ ⎦⎤n−44×10Vgn = 0.83lg and C v=SbVg + VbThis relation is applicable to highly compact mixes (≅ 3% voids).' 100 × CvFor other asphalt mixes, C v is replaced by Cv=100 + v − 3with v = percentage of voids.Francken's method: The elastic modulus E ∞ is calculated (for low temperature andhigh frequency values):The complex modulusmodulus R * " function:E ∞ = 1,436×104⎛Vg⎞× ⎜ ⎟⎝ Vb ⎠0,55Vg: aggregate volume in the mix,Vb: binder volume in the mix,v: percentage of residual voids in the mix.−2( −5,81×10× e), in MPA*E is proportional to the elastic modulus via the "reducedE**= R xE∞R * depends on the bitumen consistency at a given temperature and frequency, asVgexpressed by G* and the ratio on the following graph:Vb- 120 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -These methods do not account for the effect of aggregate type.3.6.4 Fatigue3.6.4.1 General commentsThe fatigue test is not performed as part of the mix development stage.It is still possible however to estimate fatigue resistance values by means of empiricalrelationships. Keep in mind that these assessment formulae are invalidated bychanging the type of bitumen and must therefore be used as a relative gauge.3.6.4.2 Prediction based on the direct tensile testΓ is the loss of linearity, andε( A0+ A1( − Γ)+ A2E0,300s)−46=110 ×E 0,300s is the modulus at 0°C and 300 sec.The relationships between fatigue resistance ε 6 and loss of linearity Γ have beenobtained from two databases, built by R. Linder and F. Moutier, respectively.Table 39 - Fatigue - loss of linearity relationshipLINDER coefficientsPure bitumenMOUTIER coefficientsAo 2,69 2,39A 1 5,24 3,30A 2 8,71 10 -6 -Confidence interval on ε 6 (MOUTIER coefficients) + 0,26 10 -6 (for approximately 40mix designs).- 121 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -3.6.4.3 The Shell prediction method (Shell pavement design methods, 1978)ε 6 may be estimated from the following equation:ε10( 17.4×V + 22)⎛ S ⎞⎜5 000⎟⎝ ⎠−6m6= ×b×V b : bitumen volume, expressed in %, andS m : stiffness modulus of the mix, in MPa.3.6.4.4 Francken's prediction method (fatigue test with imposed stresses)ε = KN−0,21σ 0−0,36Kb= Λb + vm3.6.4.5 LPC methodΛ : depends on both the thermal susceptibility B’ of bitumen andbitumen penetration at the loading time,b: binder volume,vm = y( ma /100)b/(b+vm) is the percentage of voids filled by the binder.The ε 6 value for bitumen content TL with respect to compacity variation ∆C forbitumen content TL can be approximated by the following equation:( ε ) = 3, ∆C∆ 362−6( −125+ 72TL− 4,85TL+ 3,3∆)ε6= C 10This equation was established for solid mineral materials N with mass density2,85 g/cm 3 and a 40/50-grade bitumen.3.6.4.6 Formula adjustment to improve fatigue resistanceFor binder contents below 7%, fatigue resistance rises with bitumen content [a 1%increase in bitumen content offers the potential of gaining 25 µdef on the value of ε 6 ].3.6.5 Texture3.6.5.1 General commentsTexture is measured on the slabs from the slab compactor with a thicknesscorresponding to that practiced on the jobsite, and preferentially of dimensions500 mm x 600 mm.- 122 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -An average texture depth (ATD) test is performed on the slab, as set forth in theEN 13036-1.As an initial approximation, the following formula can be employed:ATD (PmT) = ATD (PmT) + 0,3 mm3.6.5.2 Adjustment to the average texture depth valueTable 40 - Adjustment to average texture depthAverage texture depth (ATD)Less than the targeted valueMuch lower than the targeted valueDecrease the % fine aggregate by 5 points andincrease the > 6 mm proportionCreate a discontinuity and adjust thepercentage of fine aggregate3.6.6 Ancillary tests3.6.6.1 Percentages of communicating voids (NF P 98-254-2)This test consists of sealing the walls and base of a mix specimen witha known percentage of voids. The quantity of water absorbed by thespecimen yields the volume of communicating voids, as expressed inpercentage terms compared to the volume of voids; the resulting valuegenerally lies between 16% and 20% for the PA-BBDr material.3.6.6.2 Cantabre Test (EN 12 697-17)This shock resistance test is practiced on Porous Asphalt mixtures and,above all else, highlights binder consistency properties. Its relevancewith respect to behavior under road conditions remains to bedemonstrated.3.6.6.3 Drainage (EN 12697- 18)This test is practiced on drainage mixes as well as stone mastic asphalt(SMA); it takes place at the mixing temperature and is intended toevaluate the loss of mastic during material transport. Two methods maybe employed herein: the "basket" method for drainage materials, andthe Schellenberg method for SMA.3.6.6.4 Specimen permeability (EN 12697- 19)This test also applies to drainage mixes. A constant-height watercolumn is placed on a cylindrical specimen and percolates into thespecimen for a given period of time, either vertically or horizontally.- 123 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -3.7 Practitioners' advice3.7.1 Effect of mix design factors – SummaryTable 41 - Practitioners' advice – Mix refinement [for a given type of mix] –Summary of the effect of mix design factorsPercentage of voidsTo decrease Water resistanceRutting resistanceTo increase Stiffness modulusTo increase +++ Very positive effect on the characteristic needingcorrectionFactors / effectIncrease % fine aggregate+++Increase discontinuity++Increase 10% rounded fineaggregate++Increase bitumen content+Increase enhancer+Increase bitumen content+Increase activated fines+ 2/6 fraction% fine aggregate+ + +Increase angularity+ +Lower bitumen content+Lower bitumen grade+Increase incorporation of PE+ +Increase special bitumen+ + bitumen hardness + + binder content+ +(The stiffness modulus firstrises, then drops as a functionof binder content.)Increase inclusion of PE+Induced effectRutting risk- -Rutting risk- -Rutting risk- - -Rutting risk- --Rutting risk-Decrease percentage of voids-Fatigue, sealant-Voids-Fatigue / water resistance-Top-down cracking-Top-down cracking-Rutting / fatigue---- Very negative effect on another characteristic++ Positive effect on the characteristic needingcorrection+ Medium or weak effect on the characteristic needingcorrection-- Negative effect on another characteristic- Risk of negative effect on another characteristic- 124 -


LPC Bituminous Mixtures Design Guide- Mix Design Procedure -3.7.2 Practical tips for the mix designerDuring the mix design study, it is possible: to select the order by which the variousproperties are to be verified, or to provisionally streamline verification methods tosave time and reduce material quantities, or to take the liberty to investigate broadervariation ranges among the set of mix parameters.Priority must be assigned to achieving the main targeted characteristic, once thecompactibility characteristics have been verified. As an example, when devising theAC-EME mix design, the stiffness modulus at 15°C / 10 Hz is to be verified, andshould fatigue-related properties be studied, just a single test level at the intendeddeformation for 10 6 cycles will be performed. If the result obtained exceeds this lifecycle duration, the full panoply of tests may be undertaken. At this stage, thepredictive relations involving mechanical characteristics (modulus, fatigue) vs. mixdesign factors can be introduced to optimize the design more quickly, for subsequentsummary verification prior to the full test.In all cases, as the optimization process unfolds, it remains possible to reduce thenumber of samples (e.g. a single Gyratory Compactor specimen, a single WheelTracking Tester specimen, scaled-down version of the ITSR method B test (Durieztest), just one fatigue level). It is entirely feasible to test two different mix designspecimens during the same Wheel Tracking test.On the other hand, as regards the final design, the complete battery of tests provesnecessary for each one of the specified properties.- 125 -


LPC Bituminous Mixtures Design Guide- Relationships between laboratory and field résults -4 RELATIONSHIPS BETWEEN LABORATORY AND FIELD RESULTSSince the French method has been based on specifying characteristics in thelaboratory for a given mix, it is still necessary to comprehend the relationshipsexisting between results obtained from a sample prepared in the laboratory and asample extracted in the field. The consistency of this approach (laboratoryevaluation / performance predictions for pavements) was verified for certain datapoints. The magnitude of economic stakes tied to actual performance obtained fromthe pavement along with the evolution in production and implementation capacitiesnecessitate however focusing, for shorter-interval periods, on the correspondencebetween values measured on specimens made in the laboratory and those generatedon the jobsite.This verification step was performed during a number of studies conducted onvarious properties, such as gyratory compactor compactibility, rutting, stiffnessmodulus and fatigue resistance. The approach adopted in all cases consisted ofcomparing results from laboratory analysis (ensuring that components tested wereactually being used onsite) with results obtained from samples extracted in the field,in including a careful estimation of their variability.As regards rutting properties, the results presented stem from two specific jobsite vs.laboratory comparative studies conducted in France and the United States. For theproperties of compactibility with the gyratory compactor, stiffness modulus andfatigue resistance, results were drawn from the LPC research topic: "CH15 : Designof hot asphalt mixes". In this particular study, the mix was prepared in the laboratoryby varying the binder content around the design value, which led to an initial set oflaboratory results. On worksites, the group of results for a given mix and specific testcomprised a large number of sample extractions (> 20). A comparative assessmentof these two results has yielded the conclusions laid out in the following sections.4.1 Percentage of voids measured with the Gyratory Compactor (GC)4.1.1 Experimental objectiveOn several worksites, results were collected from:- the preliminary design, carried out prior to initiating the works;- laboratory verification using actual site materials;- site tests, with mix materials being output from the mixing plant, by means ofthe "onboard" Gyratory Compactor; and- percentage of voids measurements using a gamma-densitometer bytransmission (or in certain cases using a retro-diffusion gamma-densitometerafter calibration).Compaction conditions at the measurement point locations were also verified.Conditions at the analyzed worksites are summarized in the following table:- 127 -


LPC Bituminous Mixtures Design Guide- Relationships between laboratory and field résults -Table 42 - Site conditionsType of mix -CategorySiteLayer -thicknessApplicationType of worksiteAC20-GB - Category 2Volcanic aggregates(gabros, rhyolite,rhyolitic tuff)35/50 bitumen 4,2% ext1RN 7Base10 cm(2 layers)SpreadingFull width 8 mCompaction2 tire - 5 tons/wheel2 smooth (Dynapac 511)Major highway worksitePace: 4000 tons/dayAC20-GB - Category 3Volcanic aggregates(gabros, rhyolite,rhyolitic tuff)35/50 bitumen 4,8% ext2RN 7Foundation13 cmSpreadingVariable widthapprox. 4 mCompaction1 tire - 5 tons/wheel1 smooth (Dynapac 511)Small job successfullycompletedAC14-GB - Category 3Microdiorite aggregates35/50 bitumen 4,2% ext3RN 149Foundation10 cm(3 layers)SpreadingWidth 8 mCompaction2 tires - 3 tons/wheel2 smooth (CC 501)Medium-sizedconstruction sitePace: 1500 tons/dayAC14-GB - Category 3Vescular basaltaggregates35/50 bitumen 4,2% ext4A 89Foundation9 cm(2 layers)SpreadingWidth 8 mCompaction2 tires - 5 tons/wheel2 vibrating (CB 624)Highway building sitePace: 2000 tons/dayAC20-EME - Category 2Volcanic aggregates(gabros, rhyolite,rhyolitic tuff)10/20 bitumen 5,8% ext5RN 7Foundation10 cm(2 layers)SpreadingWidth 3,,5 mCompaction1 tire + 1 smoothvariable compactionSmall jobsite withconsiderable number ofproject hazards, difficultworking environmentAC10-BBSGMicrodiorite aggregates35/50 bitumen 4,8% ext6RN 7Bindercourse5 cmSpreadingFull width 10 mCompaction3 tires - 4 tons/wheel3 smooth (CC 501)Major highway projectPace: 3000 to3500 tons/dayNote: The tire compactors used, depending on the type of mix, were ballasted between 3 and 5 tons/wheel. Only the gravebitumeAC-GB from the A89 highway job, recognized as difficult to compact, has been compacted by means of vibration usingapproximately 6 to 8 passes of a medium-loaded vibrating roller; The other mixes are compacted according to the protocol of theheavy front tire followed by a smooth compactor.4.1.2 ResultsFor the 0/20 mixes, the criterion selected for the Gyratory Compactor (GC) test is thepercentage of voids at 120 gyrations, while for the 0/14 and 0/10 Asphalt ConcreteAC-BBSG mixtures this criterion is the percentage of voids at 100 gyrations and60 gyrations, respectively.The reference value is set as the "design verification", since this criterion seems themost reliable, given that it has been obtained using materials found onsite.- 128 -


LPC Bituminous Mixtures Design Guide- Relationships between laboratory and field résults -The variability study was conducted on jobsites implementing LCPC's mobileGyratory Compactor (GC), along with a parallel fabrication control. An example ofobtained results is provided in Figure 30 below:Figure 30: Example of GC variability in the percentage of voids obtained onsite12,0AC20-GB - Class 2 - % of voids at 120 gyrations10,0% voids at 120 gyrations8,06,04,02,0P1P2P3P4P6P70,0Bitumen content% FinesP8P10Void content byGyratory compactionSpecific resultLaboratory validationMean value of 32Gyratory resultsP12P14P16P17P18P19P21P22P24P25Preliminary type testing-0,2 0,2 -0,4 0,10,3 0,6 -0,3 1% passing the 2-mm sieve-2 2 -4 4P26P28P30P32Deviationfrom thetheoreticalformulaThe main output relative to the preliminary design, verifications, variability and fieldresults have been compiled in Table 43.- 129 -


LPC Bituminous Mixtures Design Guide- Relationships between laboratory and field résults -Table 43 - % of void measurements – Comparison of laboratory compactor results (design, verification)with onsite results (Gyratory compactor, bulk density (MVA) measurement using gamma-densitometry)Site No.% of voidsNumberof testsAverage%Min%Max%Spread%Deviation fromthe verification12356Asphalt concrete for base AC20-GB - Class 2 – RN 7Preliminary design * *** 10,8 + 3,6Design verification * *** 7,2 -Inspection on sizablesample (Autun) *MobileCompactor *Gyratory10 7,4 6,5 9,2 2,7 + 0,232 7,4 6,2 9,4 3,2 + 0,2Jobsite ** 148 9 7,3 11,7 4,4 + 1,8Asphalt concrete for base AC20-GB - Class 3 – RN 7Preliminary design * *** 7,1 + 2,0Design verification * *** 5,1 -MobileCompactor *Gyratory8 6,3 4,3 7,7 3,4 + 1,2Jobsite ** 10 6,5 4,7 8,4 3,7 + 1,4Asphalt concrete for base course AC20-GB 3, 6/10 gap-graded - Class 3 – RN 149Preliminary design ( * ) *** 9,9 + 2,0Design verification ( * ) *** 7,9 -Mobile GyratoryCompactor ( ) 41 9,1 7,6 10,4 2,8 - 1,2*Jobsite ( ** ) 41 8,2 5,6 11,2 4,4 + 0,3High modulus asphalt concrete for base course AC20 (EME 0/20) - Class 2 – RN 7Preliminary design ( * ) *** 3,9 + 1,0Design verification ( * ) *** 2,9 -Mobile GyratoryCompactor ( ) 23 3,3 1,8 5,2 3,4 + 0,4*Jobsite ** 81 5,5 2,2 10 7,8 + 2,6Asphalt concrete AC10-BBSG – RN 7Preliminary design [ * ] *** 9,4 + 2,6Design verificationMobile GyratoryCompactor (LCPC) [ * ] *** 6,8 -Design verificationGyratory Compactor(LR Autun) [ * ] *** 7,4Mobile GyratoryCompactor [ ] 32 7,8 6,2 9,4 3,2 + 1,0*Jobsite ( ** ) 40 6,5 4,0 8,6 4,6 - 0,3* Results using the Gyratory Compactor at 120 gyrations, ( * ) at 100 gyrations, [ * ] at 60 gyrations** Inspection using the point gamma-densitometer, ( ** ) Inspection using the back-scattering gamma-densitometer*** Average of at least 3 repetitions- 130 -


LPC Bituminous Mixtures Design Guide- Relationships between laboratory and field résults -4.1.3 CommentsThe Gyratory Compaction test specifications associated with product standards havebeen met for all laboratory verifications using site components.The results obtained for in situ percentage of void measurements using the gammadensitometercomply with standard-based specifications (i.e. the average onsitevalue measured must be comparable with designated thresholds). For the majority ofjobsites, the results derived practically all satisfy the limits indicated in the standard.For site no, 5, submitted to execution uncertainties, results show greater dispersion.Deviations between the preliminary design with Gyratory Compactor and the designverification step may appear and to a significant extent (such is the case for AC20-GB for base course , class 2 [binder content > 4,0% (int), stiffness > 9000 MPa,fatigue > 80 µdef] (site no. 1) and class 3 [binder content > 4,4% (int), stiffness >9000 MPa, fatigue > 90 µdef] (site no. 2): 3,6% and 2,0% deviation), due to the nonrepresentativenessof preliminary design materials and sometimes to a sizable lagbetween preliminary design and site execution (case of the AC14-GB for base courseat site no, 3: 2% deviation, 4-year time differential).For conventional materials and appropriate application conditions, the percentage ofvoids yielded by the Gyratory compactor test during the verification step with jobsitecomponents provides a satisfactory order-of-magnitude estimation of the percentageof voids found on site, The maximum deviation comes to between -1,2% and +1,4%.In the case of faulty compaction (i.e. site no. 5), the average value controlled usingthe gamma-densitometer is abnormally high (+ 2% vs. the verification value), with avery wide dispersion (9% spread).The laboratory verification with worksite components and the average site value withthe mobile Gyratory lead to the same orders of magnitude, taking into account thetest reproducibility.The variability in percentage of void figures measured on construction sites (with thegamma-densitometer) is always greater than that using the mobile Gyratory, sinceoutside of fluctuations specific to the material (as reflected in large part by theGyratory test), application-related fluctuations are at work (layer thickness, supportbearing capacity, and especially compaction energy). In the general case, theaverages of these two populations compare closely with one another.Specifications relative to the percentage of voids indicated in the product standardsare realistic and, in most instances, well respected.Provided that aggregate samples are highly representative, which is the case herefor the "verification" step, Gyratory tests prove to be effective predictors of averagefield values.The production process does not exert any impact on the average "percentage ofvoids" parameter. The production average value is the same as that derived duringthe laboratory investigation. The production process in fact introduces a variabilityof +1,5%.- 131 -


LPC Bituminous Mixtures Design Guide- Relationships between laboratory and field résults -4.2 Large device wheel tracking test4.2.1 The studies conducted in FranceThe comparative studies performed on the basis of sample preparation protocol (inthe laboratory, mixed – i.e. mixing plant production and laboratory compaction, andfrom mix plate samples extracted on worksites) systematically demonstrate theenhanced rutting resistance of field materials. This deviation however is inconsistentand depends on material sensitivity to rutting.As an initial approximation, the following may be adopted:- a rather close similarity in results, provided the mix design displays decent ruttingresistance (e.g. less than 5% at 30000 cycles): deviation of 1% to 2% lower in favorof the worksite;- a major deviation in the formula sensitive to rutting (e.g. 10% at 3000 cycles); thisdifference could reach tenfold in terms of number of cycles, for a given level ofpermanent deformation, which could (as an illustration) reflect a laboratory rut depthof 10% at 3000 cycles, in comparison with a 10% onsite rut depth after 30000 cycles.Figures 32, 33 and 34 show examples of results obtained during wheel trackingexperiments conducted in 1992 on the LCPC-Nantes accelerated test carousel.Figure 31: LCPC Fatigue Carousel- 132 -


LPC Bituminous Mixtures Design Guide- Relationships between laboratory and field résults -Figure 32: Results obtained with the Large Device wheel tracking Tester - Study of laboratoryrutting10050/70multigrade 50/70% frutting10AC-EME10/20SBS110 100 1000 10000 100000Number of cyclesFigure 33: Results obtained with the Large Device wheel tracking Tester - Study of rutting onplant-produced mixes10050/70% rutting10multigrade 50/70HardSBS1100 10000 1000000Number of cycles- 133 -


LPC Bituminous Mixtures Design Guide- Relationships between laboratory and field résults -Figure 34: Behavior of mixes on the LCPC test carousel,evolution of rut depth submitted to a single large wheel (F = 42,5 kN, V = 40 km/h)141210864200 50000 100000 150000 200000Number of loadingsBB Reference BB EM BB SBSIt could be anticipated that producing a plant mix leads to likely evolution throughbinder aging, potentially associated with a modified bitumen structure (eventuallycharacterized by lower thermal susceptibility of the binder), and thus to improvedrutting resistance. Though laboratory rutting behavior offers a more pessimistic viewthan reality on the worksite, the conclusion of systematically accommodating a higherlevel of laboratory rutting may not be forwarded. The benchmark for designspecifications is based directly on both results determined in the laboratory,according to the laboratory mixing method protocol, and actual behavioralobservations made on pavements, depending on the combination of mechanical andthermal loadings.In seeking to determine the resistance to rutting from field sampling, it would benecessary to modify and strengthen specifications in order to account for thediscrepancies between laboratory and jobsite that were mentioned above, byrecalling that deviations also depend on material sensitivity, which significantlycomplicates the determination of these new thresholds. Rutting results, whenobtained using different sample preparation modes, must never be compared.4.2.2 Colorado studyTowards the beginning of the 1990's, a major study was conducted by the U,S,Federal Highway Agency (FHWA) in the state of Colorado (T, Aschenbrener),intended to assess the pertinence of the LPC large device wheel tracking test as ameans for qualifying field behavior. This study consisted of comparing LPC wheeltracking test results (extraction of in situ material plates) to older pavement surfacingwith known onsite performance (rut depth measured on the pavement). The origin ofmaterial rutting flaws on these test sections had been due to either defective designor construction (poor mix design), thereby making material age, which from a rutting- 134 -


LPC Bituminous Mixtures Design Guide- Relationships between laboratory and field résults -perspective tends to reduce deformation (i.e. binder hardening due to aging).potentially considered as a secondary factor. A total of 31 sites were selected. Thecomparisons of laboratory and field results have been summarized in the followingtable:Table 44 – Comparison between the field behavior of material mixes andthe acceptance or rejection criterion according to French specificationsEffective field performanceNo ruttingRuttingResults obtained with Good* 4 0LCPC large devicewheel tracking testPoor* 11 16NOTE: A good or poor indication with respect to French specifications < 10% at 30,000 cycles and a 60°C test temperatureThese results led to the following conclusions (extracted from the study article):- The study has highlighted the capacity of the rut tester to predict pavementbehavior;- The correlations of LCPC rut tester results with rutting depth in the field areexcellent when temperature is taken into account (based on two levels: laboratorytesting at 50°C and 60°C for onsite temperatures of 27-32°C and 32-38°C,respectively) along with site traffic (once again based on two levels: above and belowan EDLA value of 400).(The LCPC wheel tracking test on Colorado pavements – T. Aschenbrener –Colorado Department of Transportation, USA – RGRA No, 729 – May 1995)It is recalled that temperature and especially legal load conditions are very differentbetween the United States and France (in terms of axle load: just 80 kN in the U.S.vs. 130 kN in France). Since these parameters exert a strong impact on theresistance to rutting, account should be made of this fact in both test protocols andspecification thresholds.4.2.3 Ranking of mix rutting behaviorThe ranking of mixes, according to their sensitivity to rutting, remains identicalbetween laboratory and worksite (provided the mix design has been respected).Nonetheless, laboratory testing is a better indicator of deviations among materialcompositions than data obtained from field samples. The selectivity inherent inlaboratory tests, with respect to the rutting criterion, proves highly relevant in terms ofin situ behavior and facilitates differentiation across materials, making it possible tostudy sensitivity and composition optimization factors.- 135 -


LPC Bituminous Mixtures Design Guide- Relationships between laboratory and field résults -4.3 Stiffness modulus test4.3.1 Experimental objective and procedureThe French mix design method relies on the laboratory determination of variouscharacteristics that allow predicting the in situ performance of bituminous materials,An LPC research project (CH 15: "Design of hot asphalt mixes") was thus undertakento respond to such questions. This program purposely focused on pavementstructure materials (primarily asphalt concrete for base course (AC-GB grave-bitume)and AC-EME high-modulus asphalt concrete mixes) in addressing, to the greatestextent possible, the main categories of materials used in road and highwaystructures, along with a wide range of aggregate origins.In particular, it was sought to characterize the variations in stiffness modulusobtained in the field. To proceed, some 20 extraction sites were determined in thefield, distributed over the entire length of the jobsite (approximately 10 km). At eachsite, two core samples 150 mm and 300 mm in diameter were produced. The150 mm samples yielded prismatic specimens for determining the direct tensilemodulus, In each of the 300-mm diameter samples, 3 trapezoidal specimens wereextracted in order to derive the complex modulus. The identification of 3 individualresults at any single point served to estimate local variability.Field values were then compared with laboratory values on materials produced usingthe worksite formulation and components.Figure 35: In situ core samplingFigure 36: In situ sawing- 136 -


LPC Bituminous Mixtures Design Guide- Relationships between laboratory and field résults -4.3.2 Results4.3.2.1 In situ variabilityTwo examples of the variability obtained on a AC-GB grave bitume foundation layerare shown in the following figures:Figure 37: Variability in stiffness modulus on in situ extractions (site no, 1)Modulus variability at 15°CModulus (MPA)170001600015000140001300012000Modulus (MPAMAER prismatic 0,02 sec11000|E*| 10 Hz (average 3 samples)100000 5 10 15 20 25Sample numberFigure 38: Variability in stiffness modulus on in situ extractions (site no, 2)Modulus variability at 15 °CModulus (MPA)17000160001500014000130001200011000100009000Modulus (MPAMAER prismatic 0.02 sec|E*| 10 Hz (average 3 samples1 6 11 16 21Sample number- 137 -


LPC Bituminous Mixtures Design Guide- Relationships between laboratory and field résults -The weak level of dispersion should be noted between the 3 complex modulus valuesmeasured on the 3 specimens originating from a single coring. The average deviationbetween the 3 values measured at 15°C / 10 Hz comes to 460 MPa, with allindividual deviations lying below 700 MPa (except for a single point, where thisdeviation reached 1100 MPa).For the two worksites examined herein, out of some twenty extractions performed, adispersion on the order of 25% to 40% was observed, i.e. a coefficient of variationequal to 5,5% to 9,1%.It should also be pointed out that in both cases, the values measured onsite exceedthe specifications for bituminous aggregates. Attention can nonetheless be drawn tothe case of site no. 2. where the lowest value obtained randomly (on the order of9450 MPa for a void content of 9,6%), lies close to the threshold value of the class 3of grave-bitume, AC-GB3 specification. This value is indeed significant in that themoduli measured on the three specimens stemming from the same core sampledisplay a small deviation of 400 MPa.On the two studied sites the complex modulus at 15°C, 10 Hz and the direct tensilemodulus at 15°C, 0,02s are of the same order of magnitude for most of the extractionsites.4.3.2.2 Worksite - laboratory comparisonFor both field sites discussed above, the average value of complex moduli measuredonsite is situated close to that resulting from the laboratory study.Figure 39 offers a summary of results obtained from all studied sites underinvestigation and underscores the following elements:• the main laboratory results (minimum, average and maximum value from amongthe full set of results: composition variants, various measurement methods);• the main field results (minimum, average and maximum value from the set ofmeasurement results); and• for sites not incorporated into any variability study, an estimation of extremevalues derived by applying an arbitrary variability of 30%,- 138 -


LPC Bituminous Mixtures Design Guide- Relationships between laboratory and field résults -Figure 39: Laboratory-worksite correlation:Stiffness modulus at 15°C (0,02 sec or 10 Hz)Modulus, inMPaComparison of sets of results2200020000Interval ofworksitevalues191242050018000160001483316639162461607514892Mini140001200010000126001226712168123461188111722131559723AveMax8000LaboratoryJobsite 1JobsiteJobsite 1LaboratorySITE 2JobsiteSITE 2LaboratorySITE3JobsiteSITE 3Range 30%SITE 3LaboratorySITE 4JobsiteSITE4Range 30%SITE 4LaboratorySITE 5JobsiteSITE 5Range 30%SITE 5The range of field results for a given site was determined simply by taking maximumand minimum values from the entire set of results obtained.It could be observed that the variability in laboratory-measured values was of smallmagnitude.The laboratory-measured values correspond well with the average field-measuredvalues for sites 1, 4 and 5 and with the minimum values measured on sites 2 and 3.Standards specify minimum stiffness modulus values (at 15°C, 10 Hz or 0,02 sec)measured in the laboratory. These values are then used for designing the pavementstructures. For asphalt concrete for base course (AC-GB graves-bitume) [Classes 2and 3], the minimum value equals 9000 MPa; for AC-EME high-modulus mixes, thisvalue climbs to 14000 MPa.For all 5 sites, the minimum modulus values measured in the field are either greaterthan or equal to the minimum value specified in laboratory tests.The onsite performance between asphalt concrete for base course AC-GB and highmodulusasphalt concrete mixes, AC-EME turns out to be highly differentiated.It proves impossible, from these results, to detect any "material nature" effect.- 139 -


LPC Bituminous Mixtures Design Guide- Relationships between laboratory and field résults -4.4 Fatigue test4.4.1 Experimental objective and procedureAlong the same lines as for stiffness modulus values, this CH15 research project on"Design of hot asphalt mixes" focused on the fatigue performance of pavementstructure materials (Grave bitume AC-GB and high-modulus mixes AC-EME for themost part) by means of encompassing, to the greatest extent possible, the maincategories of materials used in road and highway structures, as well as aggregates ofwidely-varying origins.Series of large-diameter core samples were extracted on sites featuring asphaltconcrete for base course (Graves-bitume) AC-GB and asphalt concrete for surfacecourses mixes AC-BBSG. These samples yield trapezoidal specimens that allowconducting about ten fatigue tests (protocol calling for a smaller number of replicas),so as to derive an estimation of worksite variability. Only results from the A77highway site, using a asphalt concrete for base course Class 3 (AC-GB class 3), willbe presented here.4.4.2 Results obtainedFigure 40 displays a summary of the fatigue results obtained in accordance with thevarious sample preparation protocols,Figure 40: Summary of fatigue test results by sample preparation protocol(preliminary design, laboratory verification, onsite extractions)110variability of epsilon 6105epsilon6 (µdefs)10095908580123456measurement location78910average sitepreliminary studylaboratory studyThe results obtained on this site incite the following comments:⎯A small dispersion in mechanical properties:• average stiffness modulus variation (average of 4 repeated tests persite): 10940 to 13584 MPa (± 10% of average value);- 140 -


LPC Bituminous Mixtures Design Guide- Relationships between laboratory and field résults -⎯⎯⎯⎯⎯⎯• the fatigue criterion varies from 91 to 106 µdef (± 7% of average value).In conjunction with these findings, it has been observed that placementconditions are very well respected (9 to 10 cm thickness, 3 to 5% void content ontested samples, i.e. 1 or 2 points more in place for the foundation void content).A very strong level of correspondence between preliminary design,laboratory verification and average "site" findings. The deviations in both modulus(1300-MPa spread) and fatigue (5-µdef spread) are less than the test toleranceranges.A compensation between modulus values and the fatigue criterion for onsiteextractions (in general, as the modulus increases, the fatigue criterion decreasesand vice versa).A very high level of regularity from fatigue tests on the "site" samples, withtest dispersion reflected by the residual standard deviation σ x/y being limited (onaverage 0,48 and a min/max spread of 0,33 to 0,67); this value is to becompared with the laboratory verification result (σ x/y = 0,67). These resultsconfirm efficient worksite scheduling, thereby leading to dispersions no greaterthan those observed on the laboratory preparations.As for the asphalt concrete for base course (Grave-bitume) class 3 AC-GB3standard specifications (modulus of 9000 MPa and fatigue > 90 µdef), theindividual results from onsite extractions always exceed these thresholds,especially for modulus value (confirmation from experience gained on modulusmeasurements). In contrast, the fatigue criterion remains narrowly limited(minimum of 91 µdef).It is also to be noted that the percentage of voids lies below the rangeestablished in the standard for determining mechanical properties (i.e. 7% to10% for asphalt concrete for base course (Grave-bitume) class 2, AC-GB2 andclass 3, AC-GB3, yet 5% and 10% for a category 4). This asphalt concrete forbase course (AC-GB Grave-bitume) category 4, AC-GB4 is the one sought bythe highway sector; the target modulus thus stands at 11000 MPa andEpsilon 6 > 100 µdef; these values, on average, are attained yet such is not thecase for the minimum fatigue values.- 141 -


LPC Bituminous Mixtures Design Guide- Relationships between laboratory and field résults -4.5 Synthesis of the relationships between laboratory and field resultsThe method described in the certified 2 nd -generation French standards and thus inEN 13108 series, as presented in this guide's second chapter on "Type testing ofasphalt mixtures", has been verified for structural type materials. Results obtained inthe laboratory on commonly-used worksite materials comply with requirements laidout in the standards.The consistency of the approach based on laboratory-determined performance hasbeen verified:1. For percentage of void values measured using the gyratorycompactor, which comply with the ranges prescribed in the standards andare representative of measured in situ values, the production process doesnot introduce any bias;2. For stiffness modulus measurements, which also comply withstandard prescriptions and for which field values are either equal to orgreater than laboratory measurements. As regards the modulus values, itshould be noted that a single isolated value from a site extraction cannot begeneralized for the purpose of bringing into question the pavement design.3. Concerning fatigue tests, the material studied exhibitedperformance values below the expected benchmark (AC-GB3 instead of AC-GB4), The correlation between laboratory values and field values is quitegood and shows little dispersion.4. The orders of magnitude for dispersion observed on sites wherethe current state-of-the-art has been adequately respected are as follows:• Gyratory Compactor: base course mixtures ± 2 to 2,5 points,surface layer mixtures ± 1 to 1,5 points• Modulus values: ± 20% to 30%• Fatigue: ± 10% to 15%• Rut depth (large device): approximately 2 points for a mixtureshowing little sensitivity to rutting (< 5% at 30000 cycles)5. The mechanical properties measured on a single coring mustnot be selected as a hypothesis in carrying out an inverse design calculationthat serves to estimate a new life cycle duration for the project.The values obtained onsite display an unavoidable level of dispersion. A largenumber of results must therefore be available in order to generate an actual view ofin situ performance. The worksite-laboratory results comparison can only be utilizedby incorporating these variability data since study conclusions are capable ofchanging entirely, depending on whether the value obtained from a single site sampleis high or low. For this reason, no conclusion should be forwarded on the basis of asingle extraction performed on the worksite.- 142 -


LPC Bituminous Mixtures Design Guide- Conclusion -5 CONCLUSIONAll steps associated with this approach have been preserved in the application of ENstandards, including the water-sensitivity in the revised version of the EN standard,which is assessed via a direct compression test. As regards "structural" materials, itis indeed possible to apply a "fundamental" approach, a situation alreadyencountered in today's contracts that implement a rational design process,In contrast, for wearing course mixtures, the approach employed remains highly"empirical" (not just in a EN sense of the term, but as commonly understood as well),The efforts undertaken in refining tests to evaluate surface characteristics of mixes inthe laboratory, along with their durability characteristics, must be pursued in order toderive a truly fundamental approach in this field.- 143 -


LPC Bituminous Mixtures Design Guide- Bibliography - -BibliographyBitumes et enrobés bitumineux – Bulletin de liaison des laboratoires des ponts etchaussées Spécial V– déc. 1977[Afnor, 2000] - Recueil de normes enrobés hydrocarbonés – AFNOR – 2000[Afnor, 2000] - Recueil de normes essais relatifs aux chaussées – AFNOR – 2000[Bonnot, 1993] – Généralités sur les essais mécaniques pratiques de formulation et decontrôle des enrobés bitumineux, Mechanical tests for bituminous mixes –J. BONNOT – Symposium International Rilem, Belgrade, 1983[Boussad, Dony, 1996] – La rhéologie des liants : un outil pour prédire le module desenrobés- N.BOUSSAD, A.DONY-RGRA n°739 p22[Boutin,1995] – De la rhéologie du liant à celle de l’enrobé bitumineux, théorie del’homogénéisation et validation expérimentale – C. BOUTIN, C. DE LA ROCHE,H. DI BENEDETTO, G. RAMOND – Eurobitume workshop, Bruxelles, avril 1995[Brosseaud, 1993] – Study of permanent deformations in asphalt pavements with theuse of the LCPC wheel tracking rutting tester. Evaluation and future prospects ––Y. BROSSEAUD, JL. DELORME, R. HIERNAUX – 72 th Annual Meeting TRB,Transportation Research Record, n°1384, p. 59-68 – Washington, 1993[Ballié, 1990] – Formulation des enrobés – Bilan des essais à la presse à cisaillementgiratoire (PCG) – M.BALLIE, JL.DELORME, R.HIERNAUX, F.MOUTIER-; Bulletin deliaison des laboratoires des ponts et chaussées n°170, nov-dec 1990.[Chappat, Ferraro-Maia, 1997] – Pour y voir plus clair dans les essais SHRP et dans leursapplications aux bitumes polymères – M.CHAPPAT, A.FERRERO-MAÏA - RGRA n°753 p.52[Chauvin, 1990] – L’essai de module complexe utilisé pour la formulation des enrobés –JJ. CHAUVIN – Proceedings 4th Rilem Symposium, Budapest, 1990[Corté et al, 1994] – Investigation f Rutting of Asphalt Surface Layers : Influence ofBinder and Axle Loading Configuration– JF. CORTE, Y. BROSSEAUD, JP.SIMONCELLI and G. CAROFF – Transportation Research Record n°1436, 1994[CRR, 1987] – Code de bonne pratique pour la formulation des enrobés bitumineux –CRR (Centre de Recherche Routière) – Recommandations CRR R69, 1987[De La Roche, 1996] Module de rigidité et comportement en fatigue des enrobésbitumineux. Expérimentations et nouvelles perspectives d'analyse –C. DE LA ROCHE – nov. 1996- 144 -


LPC Bituminous Mixtures Design Guide- Bibliography - -[De La Roche, 1994] – Etude de la fatigue des enrobés bitumineux à l’aide du manègede fatigue LCPC – C. DE LA ROCHE, JF. CORTE, JC. GRAMSAMMER, H. ODEON,L. TIRET, G. CAROFF, – RGRA, n°716, 1994[De La Roche, 1996] – Module de rigidité et comportement en fatigue des enrobésbitumineux – Expérimentations et nouvelles perspectives d’analyse, thèse dedoctorat – C. DE LA ROCHE – Ecole Centrale, Paris, 1996[De La Roche , 2001] – Essais de fatigue sur les enrobés bitumineux. Résultats del’expérience d’exactitude – DE LA ROCHE – RGRA n°793, 2001[Delorme, 1992] Méthode française de formulation des enrobés – JL. DELORME –RGRA hors série – jan. 1992[Delorme, 2000] – Correspondance entre les caractéristiques mesurées sur desmatériaux de laboratoire et sur des matériaux prélevés sur chantier – Module derigidité – JL. DELORME, L. WENDLING, C. DE LA ROCHE, Y. BROSSEAUD,N. RIVIERE, C. LEROUX – EUROBITUME Barcelone, 2000[Delorme, 2000] – Correspondance entre les caractéristiques mesurées sur desmatériaux de laboratoire et sur des matériaux prélevés sur chantier – Presse àCisaillement Giratoire – JL. DELORME, L. WENDLING, C. DE LA ROCHE,Y. BROSSEAUD, N. RIVIERE, C. LEROUX – EUROBITUME Barcelone, 2000[Delorme, 1996] – Les enrobés à module élevé EME) : description, usages,performances – JL. DELORME, V. GOYON, M. GAVALDA – EURASPHALT &EUROBITUME Congress, vol 8, n°196, 1996[Di Benedetto, Corté, 2005] – Mécanique et ingénierie des matériaux – Matériaux routiersbitumineux 1 – Description et propriétés des constituants – H. DI BENEDETTO,JF. CORTE – Hermes Sciences, 2005[Di Benedetto, Corté, 2005] – Mécanique et ingénierie des matériaux – Matériaux routiersbitumineux 1 – Constitution et propriétés thermomécaniques des mélanges –H. DI BENEDETTO, JF. CORTE – Hermes Sciences, 2005[Di Benedetto, De la Roche, 1998] – State of art on stiffness modulus and fatigue ofbituminous mixtures – H. DI BENEDETTO, C. DE LA ROCHE, L. FRANKEN – Spon,1998[Duriez, 1950] – Traité de matériaux de construction – DURIEZ – éditions Dunod ,1950[Grimaux, 1979] Vers une nouvelle méthodologie d'étude des enrobés –JP. GRIMAUX – Bulletin de liaison des laboratoires des ponts etchaussées n°10411 – déc. 1979[Grimaux, Hiernaux, 1977] – Utilisation de l’orniéreur type LPC – JP. GRIMAUX,R. HIERNAUX – Bulletin de Liaison des Laboratoires des Ponts et Chaussées –Special V, LCPC, p. 165-172 – Paris ,1977[Huet] Rapport LCPC n°14 – M. HUET- 145 -


LPC Bituminous Mixtures Design Guide- Bibliography - -[Lesage, 1996] – Quand les propriétés rhéologiques du bitume peuvent-elles servir àprédire avec succès les performances des enrobés – M. LESAGE – EURASPHALT,1996[Linder, 1977] – Comportement en traction simple des enrobés hydrocarbonés –R. LINDER – rapport n°72, LCPC Paris, 1977Mines et carrières – octobre 1996, volume 78[Moutier, 1990] – Contrôle de qualité des enrobés à l’aide de machine asservied’essais rhéologiques – F. MOUTIER, JL. DELORME – Proceedings of 4thinternational Symposium, Budapest, 1990[Moutier] – Étude statistique de l’effet de la composition des enrobés bitumineux surleur comportement en fatigue » – F. MOUTIER – Bulletin de liaison des laboratoiresdes ponts et chaussées n°172 p.40[Moutier, 1996] – Modélisation des résultats de la PCG – Réflexions à propos du seuilultime de compactage – F. MOUTIER – Eurobitume Eurasphalt Congress, vol. 4,n°57, Strasbourg, 1996[Moutier, 1992] – Utilisation de la Presse à Cisaillement Giratoire et de l’orniéreur dansla méthode française de formulation des enrobés bitumineux – F. MOUTIER –Proceedings of 5th Eurobitume congress, vol 1B, Stockholm juin 1992National Research Council, Strategic Highway Research Program, The superpavemix design manual for new construction and overlays. Report SHRP-A-407,Washington, 1994[Piau, 1989] – Modélisation thermomécanique du comportement des enrobésbitumineux – JM. PIAU – BL n°163, septembre-octobre 1989[Rilem, 1998] – Bituminous binder and mixes – Rilem report, n°17, Londres 1998[SHRP, 1994] - The Superpave mix design – Manual for new construction andoverlays – SHRP – 1994[Soliman, 1976] – Influence des paramètres de formulation sur le comportement à lafatigue d’un enrobé bitumineux – S. SOLIMAN – Rapport de recherche LPC n°58,1976[Soliman, 1977] – Influence des paramètres de formulation sur le module et larésistance en fatigue des graves-bitumes – S. SOLIMAN, TH. DOAN – Bulletin deLiaison des Laboratoires des Ponts et Chaussées numéro spécial V, 1977[Usirf, 2001] - Les enrobés bitumineux Tome 1 – USIRF – RGRA – déc. 2001[Usirf, 2003] - Les enrobés bitumineux Tome 2 – USIRF – RGRA – déc. 2003[Van der Poel, 1954] – A general system describing the viscoelastic properties ofbitumen and its relation to routine test data – C. VAN DER POEL – J.Appl. Chem, vol4, n°5, 1954- 146 -


LPC Bituminous Mixtures Design Guide- Bibliography - -[William, 1955] – The temperature dependence of relaxation mechanisms inanomorphous polymers and other glasforming liquids – ML. WILLIAM, RF. LANDEL,JD. FERRY – Journal of American Chemistry Society, n°20, 1955- 147 -


LPC Bituminous Mixtures Design Guide- Appendix A – List of normative references -Appendix A:List of normative references required for the type testing phase1 - Normative references relative to mix componentsStandardEN 13043XP P18-545EN 932-2P 18-559TitleAggregates for bituminous mixtures and surface treatments forroads, airfields and other trafficked areasAggregates: Bases for definition, compliance and classificationTest for general properties of aggregates - Part 2: Methods forreducing laboratory samplesMeasurement of sand and gravel mass density in paraffin oilEN 933-1(NF P 98-256-1)(07/91)EN 932-5EN 933-3EN 933-5Tests for geometrical properties of aggregates - Part 1:Determination of particle size distribution - Sieving methodAggregates: Determination of the absorbent power of fines(For information: This reference is no longer applied in practice.)Test for general properties of aggregates - Part 5: Commonequipment and calibrationTests for geometrical properties of aggregates - Part 3:Determination of particle shape - Flakiness indexTests for geometrical properties of aggregates - Part 5:Determination of percentage of crushed and broken surfaces incoarse aggregate particlesEN 933-6Test for geometrical properties of aggregates - Determination ofsurface characteristics - Part 6: Flow coefficient of aggregatesEN 933-9Tests for geometrical properties of aggregates - Part 9: Assessmentof fines - methylene blue testEN 933-10Test for geometrical properties of aggregates - Part 10: Assessmentof fines - Grading of fillers (air jet sieving)- 149 -


LPC Bituminous Mixtures Design Guide- Appendix A – List of normative references -StandardTitleEN 1097-1Tests for mechanical and physical properties of aggregates - Part 1:Determination of the resistance to wear (micro-Deval)EN 1097-2Tests for mechanical and physical properties of aggregates - Part 2:Methods for the determination of resistance to fragmentation (LosAngeles)EN 1097-4Tests for mechanical and physical properties of aggregates - Part 4:Determination of the voids of dry compacted fillerEN 1097-7Tests for mechanical and physical properties of aggregates - Part 7:Determination of the particle density of filler - pycnometer methodEN 1097-8Tests for mechanical and physical properties of aggregates - Part 8:Determination of the polished stone valueEN 13179-1ISO 565EN 12697-11EN 58Tests for filler aggregate used in bituminous mixtures - Part 1: Deltaring and ball testTest sieves – Metal wire cloth, perforated metal plates andelectroformed sheets – Nominal dimensions of sieve openingsBituminous mixtures – Test methods for hot-mix asphalt – Part 11:Determination of the affinity between aggregate and bitumenBitumen and bituminous binders - Sampling of bituminous bindersEN 1426Bitumen and bituminous binders - Determination of needlepenetrationEN 1427Bitumen and bituminous binders - Determination of the softeningpoint - Ring and ball methodEN 12591EN 12593Bitumen and bituminous binders - Specifications for paving gradebitumenBitumen and bituminous binders - Determination of Fraass breakingpoint- 150 -


LPC Bituminous Mixtures Design Guide- Appendix A – List of normative references -StandardEN 12594EN 12607-1EN 12697-1EN 12697-3EN 12697-4EN 13924EN 14023TitleBitumen and bituminous binders - Preparation of test samplesBitumen and bituminous binders - Determination of the resistance tohardening under influence of heat and air - Part 1: RTFOT methodBituminous mixtures - Test methods for hot mix asphalt - Part 1:Soluble binder contentBituminous mixtures - Test methods for hot mix asphalt - Part 3:Bitumen recovery: Rotary evaporatorBituminous mixtures - Test methods for hot mix asphalt - Part 4:Bitumen recovery: Fractionating columnBitumen and bituminous binders – Specifications for hard paviggrade bitumensBitumen and bituminous binders – Framework specification forpolymer modified bitumens2 - Normative references relative to mix sample preparationEN 12697-5StandardTitleBituminous mixtures - Test methods for hot mix asphalt - Part 5:Determination of the maximum densityEN 12697-38Bituminous mixtures - Test methods for hot mix asphalt - Part 38:Common equipment and calibrationEN 12697-35Bituminous mixtures - Test methods for hot mix asphalt - Part 35:Laboratory mixingEN 12697-33Bituminous mixtures - Test methods for hot mix asphalt - Part 33:Specimen prepared by roller compactorNF P 98-250-3EN 12697-6EN 12697-7Pavement-related tests – Preparation of asphalt mixes – Rollercompaction – Specimen preparation within an asphalt blockBituminous mixtures - Test methods for hot mix asphalt - Part 6:Determination of bulk density of bituminous specimens byhydrostatic methodsBituminous mixtures - Test methods for hot mix asphalt - Part 7:Determination of bulk density of bituminous specimens by gammarays- 151 -


LPC Bituminous Mixtures Design Guide- Appendix A – List of normative references -StandardEN 12697-29EN ISO 13036-1TitleBituminous mixtures - Test method for hot mix asphalt - Part 29:Determination of the dimensions of bituminous specimensRoad and airfield surface characteristics - Test methods - Part 1:Measurement of pavement surface macrotexture depth using avolumetric patch technique3 - Normative references relative to laboratory testsStandardNF P 98-251-1(to be revised or superseded no laterthan end of 2007)EN 12697-12(see comments in Appendix D)TitleStatic tests on bituminous mixtures - The Duriez test conducted onhot mix asphaltBituminous mixtures - Test methods for hot mix asphalt - Part 12:Determination of the water sensitivity of bituminous specimensMethod B by compressionEN 12697-30Bituminous mixtures - Test methods for hot mix asphalt - Part 30:Specimen preparation by impact compactorEN 12697-34Bituminous mixtures - Test methods for hot mix asphalt - Part 34:Marshall testEN 12697-31Bituminous mixtures - Test methods for hot mix asphalt - Part 31:Specimen preparation by gyratory compactorEN 12697-10Bituminous mixtures - Test methods for hot mix asphalt - Part 10:CompactabilityEN 12697-22Bituminous mixtures - Test methods for hot mix asphalt - Part 22:Wheel trackingEN 12697-26Bituminous mixtures - Test methods for hot mix asphalt - Part 26:StiffnessEN 12697-24Bituminous mixtures - Test methods for hot mix asphalt - Part 24:Resistance to fatigueEN 12697-17Bituminous mixtures - Test methods for hot mix asphalt - Part 17:Particle loss of porous asphalt specimens- 152 -


LPC Bituminous Mixtures Design Guide- Appendix A – List of normative references -EN 12697-18StandardTitleBituminous mixtures - Test methods for hot mix asphalt - Part 18:Binder drainage testEN 12697-19Bituminous mixtures - Test methods for hot mix asphalt - Part 19:specimen permeability4 - Normative references relative to the methodologyStandardTitleXP P 98-135(to be revised or superseded no later Reclaimed asphalt - Classificationthan end of 2007)Asphalt mixes – Terminology – Components and composition ofNF P 98-149mixtures – Implementation – Products – Techniques andprocessesNF P 98-150-1Hot bituminous mixtures- Constituent materials, type testing,mixing, laying, controlEN 13108-1Bituminous mixtures – Materials specification – Asphalt concretesBituminous mixtures – Materials specification – Very thin layerEN 13108-2asphalt concretes BBTMEN 13108-3Bituminous mixtures – Materials specification – SoftasphaltEN 13108-4Bituminous mixtures – Materials specification – Hot-rolled asphaltBituminous mixtures – Materials specification – Stone masticEN 13108-5asphaltEN 13108-7Bituminous mixtures – Materials specification – Porous asphaltsEN 13108-8Bituminous mixtures – Materials specification – Reclaimed asphaltEN 13108-20Bituminous mixtures – Materials specification – Type testing- 153 -


LPC Bituminous Mixtures Design Guide- Appendix B- EN testing standardsAppendix B:EN testing standards - EN 12697 series: "Asphalt mixes"Use recommendationsEuropean standard Comments RecommendationEN12697-1Bituminous mixtures – Test methodsfor hot mix asphalt – Part 1: Solublebinder contentEN12697-2Bituminous mixtures – Test methodsfor hot mix asphalt – Part 2:Determination of particle sizedistributionEN 12697-3Bituminous mixtures – Test methodsfor hot mix asphalt – Part 3: Bitumenrecovery: Rotary evaporatorEN12697-4,Bituminous mixtures – Test methodsfor hot mix asphalt – Part 4: Bitumenrecovery: Fractionating columnEN12697-5,Bituminous mixtures – Test methodsfor hot mix asphalt – Part 5:Determination of the maximumdensityEN12697-6Bituminous mixtures – Test methodsfor hot mix asphalt – Part 6:Determination of bulk density ofbituminous specimensReplaces XP T 66041.Addresses the "cold extraction"method, the Kumagawa method andthe continuous centrifugationmethods.Describes asphalt mixes withpolymer modified bitumen;Amounts adapted to aggregatequantities recovered at the time ofextraction.No French standard exists on thistopic.Cited in XP P 98-135.No French standard exists on thistopic.Cited in XP P 98-135.No French standard exists on thistopic.Water method for the mixture citedin the gyratory compactor standard.Good level of correlation withmaximum density, calculated basedon P 18-559, using paraffin oil.Replaces NF P 98-250-6, measuredby means of hydrostatic weighing.Specifications on the percentage ofvoids during type testing based onthe gyratory compactor test, notaffected by these measurementmethods (direct height-basedmeasurement).Recommendedapplication; the bindercontent must beexpressed in interior %instead of exterior %.Recommendedapplication:Cores:– Method Cfor type AC-BB or GBasphalt mixes, EME– Method Dfor BBDr asphalt mixesEN12697-7Bituminous mixtures – Test methodsfor hot mix asphalt – Part 7:Determination of bulk density ofbituminous specimens by gammaraysReplaces NF P 98-250-5. Nearlyidentically written.- 154 -


LPC Bituminous Mixtures Design Guide- Appendix B- EN testing standardsEuropean standard Comments RecommendationEN12697-8Bituminous mixtures – Test methodsfor hot mix asphalt – Part 8:Determination of the characteristicair voids content of bituminousspecimensEN12697-9Bituminous mixtures – Test methodsfor hot mix asphalt – Part 9:Determination of the referencedensityEN12697-10Bituminous mixtures – Test methodsfor hot mix asphalt – Part 10:CompactabilityEN12697-11Bituminous mixtures – Test methodsfor hot mix asphalt – Part 11:Determination of the affinity betweenaggregate and bitumenEN12697-12Bituminous mixtures – Test methodsfor hot mix asphalt – Part 12:Determination of the watersensitivity of bituminous specimensEN12697-13Bituminous mixtures – Test methodsfor hot mix asphalt – Part 13:Temperature measurementEN12697-14Bituminous mixtures – Test methodsfor hot mix asphalt – Part 14: WatercontentEN12697-15Bituminous mixtures – Test methodsfor hot mix asphalt – Part 15:Determination of the segregationsensitivityEN12697-16Bituminous mixtures – Test methodsfor hot mix asphalt – Part 16:Abrasion by studded tiresEN12697-17Bituminous mixtures – Test methodsfor hot mix asphalt – Part 17:Particle loss of porous asphaltspecimensEN12697-18Bituminous mixtures – Test methodsfor hot mix asphalt – Part 18: Binderdrainage testA definition standard, and not a test. For informationpurposes.Interpretation method for acompaction test. Does notcorrespond to any specifications.Cited in EN 13043.Is not used in the current "asphaltmix" reference.Method B and preparation of thespecimens by compressioncorresponds to the DURIEZ test NFP 98-251-1No corresponding French standard.No corresponding French standard.Unstructured method.Removed from theEuropean reference not to be usedFor informationpurposes.Not to be used anylonger.Due to the low precisionof the method (given inthe standard) and theresults of experiment, themethod A is notrecommended.Recommendedapplication including onthe jobsites.Recommendedapplication.For informationpurposes.Not relevant in France.Informational; testconditions need to bespecified (temperature inparticular).For informationpurposes.Basket method for PA-BBDr.- 155 -


LPC Bituminous Mixtures Design Guide- Appendix B- EN testing standardsEuropean standard Comments RecommendationEN12697-19Bituminous mixtures – Test methodsfor hot mix asphalt – Part 19:Specimen permeabilityEN12697-20Bituminous mixtures – Test methodsfor hot mix asphalt – Part 20:Indentation using cube or MarshallspecimensEN12697-21Bituminous mixtures – Test methodsfor hot mix asphalt – Part 21:Indentation test using platespecimensEN12697-22Bituminous mixtures – Test methodsfor hot mix asphalt – Part 22: Wheeltracking testEN12697-23Bituminous mixtures – Test methodsfor hot mix asphalt – Part 23:Determination of the indirect tensilestrength of bituminous specimensEN12697-24Bituminous mixtures – Test methodsfor hot mix asphalt – Part 24:Resistance to fatigueprEN 12697-25Bituminous mixtures – Test methodsfor hot mix asphalt – Part 25: Cycliccompression testEN12697-26Bituminous mixtures – Test methodsfor hot mix asphalt – Part 26:StiffnessEN12697-27Bituminous mixtures – Test methodsfor hot mix asphalt – Part 27:SamplingEN12697-28Bituminous mixtures – Test methodsfor hot mix asphalt – Part 28:Preparation of samples fordetermining binder content, watercontent and gradingEN12697-29Bituminous mixtures – Test methodsfor hot mix asphalt – Part 29:Determination of the dimensions ofbituminous specimensReplaces T 66-002Replaces NF P 98-253-1 (Thestandard NF P 98-253-1 has beendeleted from the AFNOR reference)Nearly identically written.See position of temperature probes.Test cited in EN12697-12Replaces NF P 98-261-1.Identically written.Replaces NF P 98-260-1 and NF P98-260-2.Broader range of operatingconditions.No corresponding French standard.No corresponding French standard.No corresponding French standard.For informationpurposes.For informationpurposes,if D ≤ 11 mmRecommendedapplication,if D > 11 mmRecommendedapplication.Large-device.See remark of EN12697-12.Appendix AApplication solely underconditions associatedwith "product" standardspecifications (15°C and10 Hz or 0,02 sec).Extrapolations from otherloading times are notconsidered as valid.ApplicationApplication.- 156 -


LPC Bituminous Mixtures Design Guide- Appendix B- EN testing standardsEuropean standard Comments RecommendationEN12697-30Bituminous mixtures – Test methodsfor hot mix asphalt – Part 30:Specimen preparation by impactcompactorEN12697-31Bituminous mixtures – Test methodsfor hot mix asphalt – Part 31:Specimen preparation by gyratorycompactorEN12697-32Bituminous mixtures – Test methodsfor hot mix asphalt – Part 32:Laboratory compaction ofbituminous mixtures by vibratorycompactorEN12697-33Bituminous mixtures – Test methodsfor hot mix asphalt – Part 33:Specimen prepared by rollercompactorEN12697-34Bituminous mixtures – Test methodsfor hot mix asphalt – Part 34:Marshall testEN12697-35Bituminous mixtures – Test methodsfor hot mix asphalt – Part 35:Laboratory mixingEN12697-36Bituminous mixtures – Test methodsfor hot mix asphalt – Part 36:Determination of the thickness of abituminous pavementEN12697-37Bituminous mixtures – Test methodsfor hot mix asphalt – Part 37: Hotsand test for the adhesivity of binderon pre-coated chippings for HRA(hot-rolled asphalt)EN12697-38Bituminous mixtures – Test methodsfor hot mix asphalt – Part 38:Common equipment and calibrationEN 12697-39Bituminous mixtures – Test methodsfor hot mix asphalt – Part 39:Determination of binder content byignitionEN 12697-40Bituminous mixtures – Test methodsfor hot mix asphalt – Part 40: In situdrainabilityReplaces NF P 98-251-3.New equipment operating protocol.Replaces NF P 98-252.Nearly identically written, except formaximum density by directmeasurement according to EN12697-5, method A in water.Possibility of measuring the internalangle for type compliance.Replaces NF P 98-250-2.The replaced standard has beenincluded in the new document; yetother equipment set-ups are alsopossible.Replaces NF P 98-251-3.New equipment operating protocol.Replaces NF P 98-250-1, with a fewdifferences: no overheating even ifthe mixer is not thermo-regulated.Mixers remain unspecified.No corresponding French standard.No corresponding French standard.Equipment different from NF P 98-254-3. Relationship to bedemonstrated.Informational; withequipment investment,this application isrecommended.ApplicationRecommendedapplication.Device no. 5.1.1Informational; withequipment investment,this application isrecommended.ApplicationApplication.Application.Application.- 157 -


LPC Bituminous Mixtures Design Guide- Appendix B- EN testing standardsEuropean standard Comments RecommendationEN 12697-41Bituminous mixtures – Test methodsfor hot mix asphalt – Part 41:Resistance to deicing fluidsEN 12697-42Bituminous mixtures – Test methodsfor hot mix asphalt – Part 42:Amount of coarse foreign matter inreclaimed asphaltEN 12697-43Bituminous mixtures – Test methodsfor hot mix asphalt – Part 43:Resistance to fuelAirfieldsApplicationAirfields- 158 -


LPC Bituminous Mixtures Design Guide- Appendix C – Equivalence table between TL ext and B intAppendix C:Equivalence table between TL ext and B intB int for 2,65 TL ext for 2,65 TL ext for 2,65 B int for 2,653,50 3,63 3,50 3,383,60 3,73 3,60 3,473,70 3,84 3,70 3,573,80 3,95 3,80 3,663,90 4,06 3,90 3,754,00 4,17 4,00 3,854,10 4,28 4,10 3,944,20 4,38 4,20 4,034,30 4,49 4,30 4,124,40 4,60 4,40 4,214,50 4,71 4,50 4,314,60 4,82 4,60 4,404,70 4,93 4,70 4,494,80 5,04 4,80 4,584,90 5,15 4,90 4,675,00 5,26 5,00 4,765,10 5,37 5,10 4,855,20 5,49 5,20 4,945,30 5,60 5,30 5,035,40 5,71 5,40 5,125,50 5,82 5,50 5,215,60 5,93 5,60 5,305,70 6,04 5,70 5,395,80 6,16 5,80 5,485,90 6,27 5,90 5,576,00 6,38 6,00 5,666,10 6,50 6,10 5,756,20 6,61 6,20 5,846,30 6,72 6,30 5,936,40 6,84 6,40 6,026,50 6,95 6,50 6,106,60 7,07 6,60 6,196,70 7,18 6,70 6,286,80 7,30 6,80 6,376,90 7,41 6,90 6,457,00 7,53 7,00 6,547,10 7,64 7,10 6,637,20 7,76 7,20 6,727,30 7,87 7,30 6,80- 159 -


LPC Bituminous Mixtures Design Guide- Appendix D – Main test precisionsAppendix D:Main test precisionsTable 45 – Test repeatability and reproducibility valuesTestMeasured valueRepeatability95% (r)Reproducibility95% (R) σ r σ R ObservationsP 18-559Maximum density ofaggregate in paraffinρ 0/2 g/cm 3 0,021 0,05 0,0072 0,0194ρ 2/6 g/cm 3 0,013 0,04 0,006 0,014oil ρ 6/10 g/cm 3 0,025 0,035 0,007 0,011EN 12697-5Determination ofmaximum density ofasphalt mixesEN 12697-2EN 933-1Determination ofparticle sizedistribution byMVR kg/m 3 20 45 7,2 16Sands0,56 + 0,017 x(x = averagepassing % )0,056 x(x= averagepassing %)coarse d, D 3,5 7,7means of sieving Intermediate grades 8 16EN 12697-33Specimenpreparation bymeans of rollercompactionNF P 98-251-1Duriez testNF P 98-251-1Duriez testNF P 98-250-6Bulk densityGamma benchcompacity (%)ISO 57251996 experiment2005 experiment(provisional results)1,09 1992 experimentWater resistance r/R 0,078 0,134 0,028 0,047Resistance withoutimmersion, R (MPa)Bulk density by meansof hydrostatic weighing,% voids0,59 2,05 0,21 0,720,67 1,27 0,24 0,45ISO 57251998 experimentISO 57251998 experimentISO 57251998 experimentEN 12697-31Gyratory compactor% voids 60 gyrations 0,95 1,38 0,34 0,49% voids 10 gyrations 0,89 1,53(NF P 98-252) % voids 200 gyrations 1,04 1,57ISO 57251996 experimentEN 12697-22Wheel tracking(Large device)Rutting at 30000 cycles(in mm)1,11 1,16 0,39 0,41ISO 57251992 experimentEN 12697-26Secant modulusAnnex EModulus at0,02 sec, 15°C (MPa)Average: 15,233 MPa1,360 2,360UnpublishedexperimentEN 12697-1Binder contentEN 12697-1Binder contentEN 12697-1Binder contentBinder content 0,27 0,31 0,085 0,121All methods combined 0,214 0,348 0,076 0,123Cold soluble 0,167 0,225 0,059 0,0791995 experiment onthe XP T66-041StandardEAPICCampaign 1/2003EAPICCampaign 1/2003- 160 -


LPC Bituminous Mixtures Design Guide- Appendix D – Main test precisionsTestMeasured valueRepeatability95% (r)Reproducibility95% (R) σ r σ R ObservationsEN 12697-24Fatigue test Annex A(NF P 98-261-1)EN 12697-26Complex modulusAnnex A(NF P 98-260-2)EN 12697-7Gamma bench(NF P 98-250-5)ε 6(µdef) 4,2 8,3 1,43 2,9315°, 10Hz (MPa) 335 2,740 118 969ISO 57252000 experimentISO 57251999 experimentAsphalt core sample2,2942 g/cm 3 0,0069 0,0197 0,0024 0,007 ISO 5725Published inMarch 2003- 161 -


Appendix ESummary table – Specifications and recommendations for each type of materialLPC Bituminous Mixtures Design Guide- Appendix E – Summary table – Spécifications and recommendations- 162 -


LPC Bituminous Mixtures Design Guide- ooendix E – Summary table – Spécifications ans recommandations- 163 -


LPC Bituminous Mixtures Design Guide- Appendix F – Product family descriptionAPPENDIX FProduct family descriptionAC-BBSG Asphalt Concrete – Béton Bitumineux Semi-GrenuDefinition Bituminous mixture in accordance with EN 13108-1 characterized by a highcoarse aggregate content and designed to yield surface or binder courses with athickness of 5 cm or greater until 9 cm.Classification by the resistance to permanent deformation.Identification AC10-BBSG or AC14-BBSG according EN 13108-1Surface or binder courseEmpirical approachDesignationAC10-BBSG0 or AC14-BBSG0AC10-BBSG1 or AC14-BBSG1AC10-BBSG2 or AC14-BBSG2AC10-BBSG3 or AC14-BBSG3Main characteristicsUsualaggregatecharacteristics(minimalvalues)Type ofbinderSurface courseBinder courseCoarseaggregateFine aggregateor All-inAdded FillerFragmentation,Wear,Polishing resistanceAngularityCoarse;Fine aggregateFragmentationWearGrading requirementFlakinessFine contentGrading requirementMethylene blue valueStiffness by ring andball, Void of drycompacted fillerA 20 or LA 25 , M DE 15 or M DE 20, PSV 50C 95/1E CS 35LA 30 , M DE 25G C 85/20 or G 25/15 ;FI 25 ; f 2G F 85 ; G TC 10 ; G A 85MB F 10∆ R&B 8/16 ; V 28/38Paving grade bitumen 50/70 or 35/50Level 0Level 1Level 2Grading : %Minimum binder content AC10 : B min5,2 AC14 : B min5,00,063 5 to 80,250 10 to 25Sieve in mm 2,0 28 to 386,3 50 to 65D 90 to 100Water sensitivity Method B (I/C) ITSR 70Gyratory AC10 60 gyrations V min5 V max10AC14 80 gyrations V min4 V max9ClassificationAC-BBSG0AC-BBSG1AC-BBSG2AC-BBSG3Gyratory 10 gyrations V10G min11 Not applicableWheel Nb of cycles 30000tracking testLarge Void content of slab No perf.device {Vi= 5% Vs = 8%} determinedP 10 P 7,5 P 560°C- 164 -


LPC Bituminous Mixtures Design Guide- Appendix F – Product family descriptionAC-BBME Asphalt Concrete – Béton Bitumineux à Module ÉlevéDefinition Bituminous mixture in accordance with EN 13108-1 whose stiffness is higherthan that of a BBSG mixture and designed to yield surface or binder courseswith a thickness of 5 cm or greater until 9 cm.Classification by the resistance to permanent deformation and by the stiffness.Identification AC10 or AC14 according EN 13108-1Surface or binder courseFundamental approachDesignation BBME class 1 0/10 or 0/14BBME class 2 0/10 or 0/14BBME class 3 0/10 or 0/14Usual aggregatecharacteristics(minimalvalues)SurfacecourseBindercourseCoarseaggregateFineaggregateor All-inMain characteristicsFragmentation,Wear,PolishingresistanceAngularityCoarse;Fine aggregateFragmentationWearGradingrequirementFlakinessFine contentGradingrequirementLA 25 , M DE 15, PSV 50C 95/1E CS 35LA 30 , M DE 25G C 85/20 or G 25/15 ;FI 25 ; f 2G F 85 ; G TC 10 ; G A 85MB F 10Methylene bluevalueAdded Filler Stiffness by∆ R&B 8/16 ; V 28/38ring and ball,Void of drycompacted fillerWater sensitivity Method B (I/C) ITSR 80Gyratory AC10 60 gyrations V min5 V max10AC14 80 gyrations V min4 V max9ClassificationBBME class BBME class12Wheeltracking testLarge device60°CStiffnessFatigueNb of cycles 30000Void content of slab{Vi= 5% Vs = 8%}15°C, 10 Hz or 0,02 sVoid content of slab{Vi= 5% Vs = 8%}2 points, 10°C, 25 HzVoid content of slab{Vi= 5% Vs = 8%}BBME class3P 10 P 7,5 P 5S min9000S min11000S min11000ε 6-100 ε 6-100 ε 6-100Level 3Level 4- 165 -


LPC Bituminous Mixtures Design Guide- Appendix F – Product family descriptionAC-BBS Asphalt Concrete – Béton Bitumineux pour chaussée Soupleà faible traficDefinition Bituminous mixture in accordance with EN 13108-1 designed to yieldsurface or binder courses for flexible pavement supporting low trafficloads.Classification by the resistance to permanent deformation.Identification AC10 or AC14 according EN 13108-1Surface or binder courseDesignationUsualaggregatecharacteristics(minimalvalues)SurfacecourseBindercourseCoarseaggregateFineaggregate orAll-inAdded FillerEmpirical approachAC10-BBS1AC10-BBS2AC14-BBS3AC14-BBS4Main characteristicsFragmentation,Wear,Polishing resistanceAngularityCoarse;Fine aggregateFragmentationWearGrading requirementFlakinessFine contentGrading requirementMethylen blue valueStiffness by ring andball, Void of drycompacted fillerLA 25 , M DE 20, PSV 50C 50/10E CS 30LA 30 , M DE 25C 50/10E CS 30G C 85/20 or G 25/15 ;FI 25 ; f 2G F 85 ; G TC 10 ; G A 85MB F 10∆ R&B 8/16 ; V 28/38B min5,2Type of binder Paving grade bitumen 50/70Minimum binder contentAC10-BBS1AC10-BBS2AC14-BBS3B min4,8AC14-BBS40,063 5 to 80,250 10 to 25Grading : % Sieve in mm 2,0 28 to 386,3 50 to 65D 90 to 100Water sensitivity Method B (I/C)AC10-BBS1AC10-BBS2AC14-BBS3AC14-BBS4ITSR 80 ITSR 80 ITSR 80 ITSR 70Gyratory AC10-BBS1 40 gyrationsAC10-BBS2 60 gyrationsV min4 V max9AC14-BBS3 80 gyrationsAC14-BBS4 100 gyrationsLevel 0Level 1- 166 -


LPC Bituminous Mixtures Design Guide- Appendix F – Product family descriptionAC-BBM Asphalt Concrete – Béton Bitumineux MinceDefinition Bituminous mixture in accordance with EN 13108-1 characterized by anaverage application thickness of between 3 cm and 5 cm. The materialis designed to yield surface courses and possibly binder courses. Theparticle size distribution is most often gap-graded. Categories A, B, Cdepend on the “gap” of the grading curve.Classification by the resistance to permanent deformation.Identification AC10 or AC14 according EN 13108-1Surface or (binder) courseEmpirical approachDesignation AC-BBMA, AC-BBMB or AC-BBMC class 0AC-BBMA, AC-BBMB or AC-BBMC class 1AC-BBMA, AC-BBMB or AC-BBMC class 2AC-BBMA, AC-BBMB or AC-BBMC class 3Usualaggregatecharacteristics(minimal values)SurfacecourseCoarseaggregateFineaggregateor All-inAddedFillerMain characteristicsLA 20 or LA 25 , M DE 15 or M DE 20, PSV 50Fragmentation,Wear,Polishing resistanceAngularityCoarse;Fine aggregateGrading requirementFlakinessFine contentGrading requirementMethylene blue valueStiffness by ring andball, Void of drycompacted fillerC 95/1E CS 35G C 85/20 or G 25/15 ;FI 25 ; f 2G F 85 ; G TC 10 ; G A 85MB F 10∆ R&B 8/16 ; V 28/38V max13Type of binderPaving grade bitumen 50/70 or 35/50Polymer modified Bitumen 45/80-60 or 40/100-65Minimum binder contentB min5,00,063 5 to 80,250 10 to 23Grading : %Sieve in 2,0 27 to 37mm 4,06,3 30 to 40D 90 to 100Water sensitivity Method B (I/C) ITSR 70Gyratory Category of AC-BBM AC-BBMA AC-BBMB AC-BBMC40 gyrations V min6 V max11 V min7 V max12 V min8AC- AC- AC- AC-ClassificationBBM 0 BBM 1 BBM 2 BBM 3Gyratory 10 gyrations V10G min11 Not applicableNb of 3 000 cycles P 15cyclesWheel tracking10 000 cycles P 15test30 000 cycles No perf.P 10Large device Void content AC-BBMA determined {Vi= 7% Vs = 10%}60°C of slab AC-BBMB or{Vi= 8% Vs = 11%}CLevel 0Level 1Level 2- 167 -


LPC Bituminous Mixtures Design Guide- Appendix F – Product family descriptionAC-BBAC- Asphalt Concrete – Béton Bitumineux Aéronautique (Continu)Definition Bituminous mixture in accordance with EN 13108-1 designed to yieldsurface courses and binder courses of airfield pavements. The particlesize distribution is continuous (category C).Classification by the resistance to permanent deformation.Identification AC10 or AC14 according EN 13108-1Surface or binder courseEmpirical approachDesignation BBAC class 0BBAC class 1BBAC class 2BBAC class 3SurfacecourseMain characteristicsLA 20 or LA 25 , M DE 15 or M DE 20, PSV 50Fragmentation,Wear,Polishing resistanceAngularityCoarse;C 95/1Fine aggregateE CS 35UsualBinder FragmentationLA 30 , M DE 25aggregateWearcoursecharacteristicsCoarse Grading requirement G C 85/20 or G 25/15 ;FI 25 ; f(minimal values)2Flakinessaggregate Fine contentFine Grading requirementG F 85 ; G TC 10 ; G A 85aggregateor All-inMethylene blue valueMB F 10Added Stiffness by ring and∆ R&B 8/16 ; V 28/38ball, Void of dryFiller compacted fillerType of binderPaving grade bitumen 50/70 or 35/50Polymer modified Bitumen 45/80-60 or 40/100-65Minimum binder content AC10: B min5,4 AC14: B min5,2Level 0Level 1Level 2Grading : %Sieve inmmBBA SurfacecourseBBA Bindercourse0,063 6 to 9 5 to 80,250 10 to 252,0 35 to 45 32 to 426,3 65 to 80 62 to 67D 90 to 100Water sensitivity Method B (I/C) ITSR 80 TSR 70AC10 60 gyrationsVGyratoryVAC14 80 gyrationsmin3 V min4 V max8max7BBA BBA BBA BBAClassificationclass 0 class 1 class 2 class 3Gyratory 10 gyrations V10G mi Not applicableWheeltracking testLarge device60°C10 000 cyclesVoid content of slab{Vi= 4% Vs = 7%}n11No perf.determinedP 15 P 10 P 7,5- 168 -


LPC Bituminous Mixtures Design Guide- Appendix F – Product family descriptionAC-BBAD- Asphalt Concrete – Béton Bitumineux Aéronautique (Discontinu)Definition Bituminous mixture in accordance with EN 13108-1 designed to yieldsurface and binder courses of airfield pavements. The particle sizedistribution is gap-graded (category D), fraction 2/6 or 4/6 is missingClassification by the resistance to permanent deformation.Identification AC10 or AC14 according EN 13108-1Surface or binder courseEmpirical approachDesignation BBAC class 0BBAC class 1BBAC class 2BBAC class 3SurfacecourseMain characteristicsLA 20 or LA 25 , M DE 15 or M DE 20, PSV 50Fragmentation,Wear,Polishing resistanceAngularityCoarse;C 95/1Fine aggregateE CS 35UsualBinder FragmentationLA 30 , M DE 25aggregateWearcoursecharacteristicsCoarse Grading requirement G C 85/20 or G 25/15 ;FI 25 ; f 2(minimal values)Flakinessaggregate Fine contentFine Grading requirementG F 85 ; G TC 10 ; G A 85aggregateor All-inMethylene blue valueMB F 10Added Stiffness by ring and∆ R&B 8/16 ; V 28/38ball, Void of dryFiller compacted fillerType of binderPaving grade bitumen 50/70 or 35/50Polymer modified Bitumen 45/80-60 or 40/100-65Minimum binder content AC10: B min5,2 AC14: B min5,0Level 0Level 1Level 20,063 6 to 90,250 10 to 25Grading : %Sieve in 2,0 35 to 45mm 4,0 47 to 576,3 63 to 73D 90 to 100Water sensitivity Method B (I/C) Surface course Binder courseITSR 80 TSR 70Gyratory 40 gyrations V min5 V max9ClassificationBBA D BBAD BBA Dclass 0 class 1 class 2Gyratory 10 gyrations V10G min11 Not applicable10 000 cyclesWheel trackingtestLarge device60°CVoid content of slab{Vi= 4% Vs = 7%}BBA Dclass 3No perf.determined P 15 P 10 P 7,5- 169 -


LPC Bituminous Mixtures Design Guide- Appendix F – Product family descriptionBBTM Béton Bitumineux Très Mince (Very Thin layer Asphalt Concrete)DefinitionIdentificationDesignationUsualaggregatecharacteristics(minimal values)Bituminous mixture in accordance with EN 13108-2 to be used forsurface courses with a thickness of 2cm to 3 cm. The particle sizedistribution is most often gap-graded.Classification A, B or D by the void content using gyratory compaction.SurfacecourseCoarseaggregateFineaggregateor All-inAddedFillerBBTM6A or BBTM10D according EN 13108-2BBTM6B or BBTM10B according EN 13108-2Surface courseEmpirical approachMain characteristicsFragmentation,Wear,PolishingresistanceAngularityCoarse;Fine aggregateGradingrequirementFlakinessFine contentGradingrequirementMethylene bluevalueStiffness by ringand ball, Void ofdry compactedfillerLA 20 , M DE 15, PSV 50C 95/1E CS 35G C 85/15 or G 20/15 ;FI 30 ; f 2G F 85 ; G TC 10 ; G A 85 or G A 90MB F 10∆ R&B 8/16 ; V 28/38Paving grade bitumen 50/70 or 35/50ype of binder Polymer modifiedBitumen45/80-60 or 40/100-65Minimum binder contentB min5,0Level 0Level 1Level 2BBTM6A BBTM6B BBTM10D BBTM10BGrading : %Sieve inmm0,063 7 to 9 4 to 6 4,5 to 6,5 4 to 60,250 15 to 25 10 to 20 15 to 25 10 to 202,0 25 to 35 15 to 25 27 to 33 15 to 254,0 25 to 35 20 to 306,3 28 to 43 26 to 41D 90 to 100 90 to 100Water sensitivity Method B (I/C) ITSR 90Gyratory Category of BBTM BBTM6A BBTM6B BBTM10D BBTM10BMechanicalstabilityLarge device60°C25 gyrations V g 10 to 17 V g 18 to 25 V g 10 to 17 V g 18 to 253 000 cyclesThickness : 50 mmVoid content of slab{Vi= 11% Vs = 14%}P 15- 170 -


DefinitionIdentificationDesignationUsualaggregatecharacteristics(minimal values)LPC Bituminous Mixtures Design Guide- Appendix F – Product family descriptionPA-BBDr Porous asphalt – Béton Bitumineux DrainantBituminous mixture in accordance with EN 13108-7, with bitumen,prepared so as to have a very high content of interconnected voidswhich allow passage of water and air in order to provide the compactedmixture with drain and noise reducing characteristics. This material is tobe used for surface courses with a thickness of 3 cm to 4 cm for PA6and 4 cm to 5 cm for PA10.Classification BBDr type 1 or BBDr type 2 by the void content usinggyratory compaction.SurfacecourseCoarseaggregateFineaggregateor All-inAddedFillerPA6-BBDr1 or PA6-BBDr2 according EN 13108-7PA10-BBDr1 or PA10-BBDr2 according EN 13108-7Surface courseEmpirical approachMain characteristicsFragmentation,Wear,PolishingresistanceAngularityCoarse;Fine aggregateGradingrequirementFlakinessFine contentGradingrequirementMethylene bluevalueStiffness by ringand ball, Void of drycompacted fillerLA 20 , M DE 15, PSV 50C 95/1E CS 35G C 85/15 or G 20/15 ;FI 30 ; f 2G F 85 ; G TC 10 ; G A 85 or G A 90MB F 10∆ R&B 8/16 ; V 28/38Paving grade bitumen 50/70 or 35/50Type of binderPolymer modified Bitumen 45/80-60 or 40/100-65Minimum binder contentB min4,0Grading : %Sieve inmmPA6-BBDr1PA6-BBDr2PA10-BBDr1PA10-BBDr20,063 [2-10] 4 to 6 2 to 6 4 to 6 2 to 60,250 6 to 12 10 to 20 6 to 12 10 to202,0 [5-25] 10 to 15 5 to 12 10 to 15 5 to124,0 15 to 35 12 to 226,3 15 to 35 12 to22D 90 to 100 90 to 100Water sensitivity Method B (I/C) ITSR 80Gyratory Category of PA-BBDr PA6-BBDr1PA6-BBDr2PA10-BBDr1PA10-BBDr240 gyrations V min20V max26V min26V max30V min20V max26V min26V max30200 gyrations V min16 V min20 V min16 V min20Level 0Level 1- 171 -


LPC Bituminous Mixtures Design Guide- Appendix F – Product family descriptionAC-GB Asphalt Concrete - Grave-Bitume EmpiricalDefinitionBituminous mixture in accordance with EN 13108-1 designed to yieldlower and upper base courses with a thickness between 8 cm and16cm.Classification by binder content.Identification AC14-GB1 or AC20-GB1 according EN 13108-1AC14-GB2 or AC20-GB2 according EN 13108-1AC14-GB3 or AC20-GB3 according EN 13108-1AC14-GB3 or AC20-GB3 according EN 13108-1Lower or upper base courseEmpirical approachUpperbasecourseMain characteristicsFragmentation,Wear,Angularity (If wheeltracking test notrequired)Coarse;LA 30 , M DE 25C 95/1E CS 35Level 0Level 1Level 2Usualaggregatecharacteristics(minimal values)LowerbasecourseCoarseaggregateFineaggregateor All-inAddedFillerFine aggregateFragmentationWearGrading requirementFlakinessFine contentGrading requirementMethylene blue valueStiffness by ring andball, Void of drycompacted fillerLA 40 , M DE 35G C 85/20 or G 25/15 ;FI 25 ; f 2G F 85 ; G TC 10 ; G A 85MB F 10∆ R&B 8/16 ; V 28/38Type of binder Paving grade bitumen 35/50 or (50/70)Classification (AC-GB1) AC-GB2 AC-GB3Minimum binder content (B min3,4 ) B min3,8 B min4,20,063 5 to 8Grading : %Sieve inmm0,250 10 to 252,0 28 to 386,3 50 to 65D 90 to 100Water sensitivity Method B (I/C) ITSR 70AC14-GB 100 gyrationsGyratory AC20-GB 120 gyrationsV max11V max10Wheel trackingtestLarge device60°CVoidcontentof slab10 gyrations V10G min1110000 cyclesAC-GB2 :{Vi= 8% Vs =11%}AC-GB3 :{Vi= 7% Vs =10%}No perf.determinedP 10AC-GB Asphalt Concrete - Grave-Bitume Fundamental- 172 -


LPC Bituminous Mixtures Design Guide- Appendix F – Product family descriptionDefinition Bituminous mixture in accordance with EN 13108-1 designed to yieldlower and upper base courses with a thickness between 8 cm and16cm.Classification by stiffness and Fatigue resistance.Identification AC14-GB2 or AC20-GB2 according EN 13108-1AC14-GB3 or AC20-GB3 according EN 13108-1AC14-GB4 or AC20-GB4 according EN 13108-1Lower or upper base courseFundamental approachUsualaggregatecharacteristics(minimal values)UpperbasecourseLowerbasecourseCoarseaggregateFineaggregateor All-inAddedFillerMain characteristicsFragmentation,Wear,FragmentationWearGrading requirementFlakinessFine contentGrading requirementMethylene blue valueStiffness by ring andball, Void of drycompacted fillerLA 30 , M DE 25LA 40 , M DE 35G C 85/20 or G 25/15 ;FI 25 ; f 2G F 85 ; G TC 10 ; G A 85MB F 10∆ R&B 8/16 ; V 28/38Classification AC-GB2 AC-GB3 AC-GB4Water sensitivity Method B (I/C) ITSR 70AC14-GB 100 gyrationsVGyratoryV max10 V max9AC20-GB 120 gyrationsmax11Level 3Level 4Wheel trackingtestLarge device60°CVoid content of the slab: {Vi= 8%Vs = 11%}{Vi= 7%Vs = 10%}{Vi= 5%Vs = 8%}Number of cycles 10000 30000Category of rut depth P 10AC-GB2 AC-GB3 AC-GB4Void content of the slabs ↓ {Vi= 7%Vs = 10%}{Vi= 5%Vs = 8%}Stiffness 15°C, 10 Hz or 0,02 s S min9000 S min9000S min11000Fatigue 2 points, 10°C, 25 Hz ε 6-80 ε 6-90 ε 6-100- 173 -


LPC Bituminous Mixtures Design Guide- Appendix F – Product family descriptionAC-EME Asphalt Concrete – Enrobé à Module Élevé(High-Modulus Asphalt Concrete)Definition Bituminous mixture in accordance with EN 13108-1 designed to yieldlower and upper base courses with a thickness between 6 cm and 8 cmfor AC10-EME, between 7cm to 13 cm for AC14-EME and between 9cm and 15 cm for AC20-EME. High stiffness and fatigue resistanceallow thickness reduction for the pavements.Classification EME1 or EME2 by Fatigue resistance.Identification AC10-EME1 or AC10-EME2 according EN 13108-1AC14-EME1 or AC14-EME2 according EN 13108-1AC20-EME1 or AC20-EME2 according EN 13108-1Lower or upper base courseFundamental approachMain characteristicsUsualaggregatecharacteristics(minimal values)UpperbasecourseLowerbasecourseCoarseaggregateFineaggregateor All-inAddedFillerFragmentation,Wear,FragmentationWearGrading requirementFlakinessFine contentGrading requirementMethylene bluevalueStiffness by ring andball, Void of drycompacted fillerLA 30 , M DE 25LA 40 , M DE 35G C 85/20 or G 25/15 ;FI 25 ; f 2G F 85 ; G TC 10 ; G A 85MB F 10∆ R&B 8/16 ; V 28/38Classification AC-EME1 AC-EME2Water sensitivity Method B (I/C) ITSR 70AC10-EME 80 gyr.Gyratory AC14-EME 100 gyr.V max10V max6AC20-EME 120 gyr.AC-EME1AC-EME2Void content of the slabs ↓ {Vi= 7%Vs = 10%}{Vi= 3%Vs = 6%}Wheel trackingtestNumber of cycles 30000 30000Large device60°CCategory of rut depth P 7,5Level 3Level 4Stiffness 15°C, 10 Hz or 0,02 s S min14000Fatigue 2 points, 10°C, 25 Hz ε 6-100 ε 6-130- 174 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –Appendix G GlossaryTermSymbol orAbbreviationUnitDefinitionCommentsAdded fillerFiller of a mineral origin that has beenproduced separately.EN 13043AdditiveOrganic or mineral constituent, introducedin small quantities (e.g. organic orinorganic fibers or polymers), intended tomodify the mechanical characteristics,workability or color of mixtures.EN 13108 seriesAdditiveAdditive content(besidesadhesionagents)Additive content(besidesadhesionagents)Organic or mineral compound intended tomodify the physical or mechanicalcharacteristics of asphalt mixes.% ext. Mass of additive as a ratio of the mass ofdry aggregates.% int. Mass of additive as a ratio of the mixturemass.NF P 98-149NF P 98-149Adhesion agentAnti-strippingagentSurface active additive that serves toimprove binder-aggregate adhesion.NF P 98-149Adhesion agentcontent% Enhancing agent mass, as a ratio of bindermass.Adhesion agentcontent% Mass of enhancing agent as a ratio of thebinder mass.AggregateGranular material used in constructionapplications. An aggregate may be natural,manufactured or recycled.EN 13043AgrochemicalbinderA binder derived from vegetal matterwithout any petrochemical byproductmaterial.Air void content v % See Percentage of voids EN 12697-8- 175 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentsAir-slaked limeProduct derived through a curing processusing a very pure limestone.NF P 98-101All-in aggregateAn aggregate consisting of a mixture ofcoarse and fine aggregates; it can beproduced without separating into coarseand fine aggregates or by combiningcoarse and fine aggregates. Forbituminous mixtures 0/4, 0/6 may beusually used.EN 13043AngularityCharacteristic of aggregates with respectto the edges present on each grain.Angularity ofcoarseaggregatesC 100/0C 95/1C 90/1C 50/10C 50/30C DeclaredCharacteristic of aggregates with respectto the edges present on each grain.According to EN 13043, angularity ischaracterized for coarser alluvial or marineaggregates by completely-crushed orsemi-crushed grain categories, along withfully-rounded grains.Coarseaggregatesderived from solidrock lie incategory C 100/0Angularity offine aggregatesAngularity(former standard)Angularity(former standard)Crushing ratioAngularity(former Frenchstandard)Crushing indexE CS38E CS35E CS30E CSDeclaredAccording to EN 13043, angularity ischaracterized for fine aggregates by flowtime categories.Angularity had been evaluated by eitherthe crushing index (CI) or the crushingratio (CR) (former standard XP P18-540).RC - Ratio between the smallest dimension ofthe original coarse aggregate submitted tothe initial crushing and the D value of theresultant aggregate.IC % Percentage of elements in excess of D ofthe resultant aggregate contained in theoriginal material submitted to crushing.These measuresare no longerstandardized, yetstill do appear inbibliographies.These measuresare no longerstandardized, yetstill do appear inbibliographies.These measuresare no longerstandardized, yetstill do appear inbibliographies.Asphalt concretefor airfieldpavementsAC-BBAAsphalt concrete for airfield pavements(continuous grading curve AC-BBA C orgap-graded grading curve AC-BBA D), inaccordance with EN 13108-1.EB-BBA in theNF EN version- 176 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentsAsphalt concretefor flexiblepavementssupporting lighttraffic loadsAC-BBSAsphalt concrete for flexible pavementssupporting light traffic loads, in accordancewith EN 13108-1.EB-BBS in theNF EN versionAsphaltConcrete- GraveBitumeAC-GBBituminous mixture in accordance with EN13108-1 designed to yield lower and upperbase courses with a thickness between 8cm and 16 cm.Fundamental or empirical approachEB-GB in the NFEN versionAsphaltConcrete-Enrobé à ModuleÉlevéAC-EMEBituminous mixture in accordance with EN13108-1 designed to yield lower and upperbase courses with a thickness between 6cm and 8 cm for AC10-EME, between 7cmto 13 cm for AC14-EME and between 9 cmand 15 cm for AC20-EME. High stiffnessand fatigue resistance allow thicknessreduction for the pavements.EB-EME in theNF EN versionAsphaltConcrete-BétonBitumineuxSemi-GrenuAC-BBSGBituminous mixture in accordance with EN13108-1 characterized by a high coarseaggregate content and designed to yieldsurface or binder courses with a thicknessof 5 cm or greater until 9 cm. Classificationby the resistance to permanentdeformation.EB-BBSG in theNF EN versionAsphaltConcrete-BétonBitumineuxMinceAC-BBMBituminous mixture in accordance with EN13108-1 characterized by an averageapplication thickness of between 3 cm and5 cm. The material is designed to yieldsurface courses and possibly bindercourses. The particle size distribution ismost often gap-graded. Categories A, B, Cdepend on the “gap” of the gradingcurve.Classification by the resistance topermanent deformation.EB-BBM in theNF EN versionAsphaltConcrete-BétonBitumineux àModule ÉlevéAC-BBMEBituminous mixture in accordance with EN13108-1 whose stiffness is higher than thatof a BBSG mixture and designed to yieldsurface or binder courses with a thicknessof 5 cm or greater until 9 cm.EB-BBME in theNF EN versionAsphaltlimestoneA sedimentary rock impregnated onsite bynaturally-occurring bitumen.- 177 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentsAverage TextureDepthATDmmMeasurement of texture using depth “Sandpatch” method accordingEN 13036-1PmtmmFrench transcription of ATDBase series +series 1mmSeries of sieves containing the following dor D dimensions: 0, 1, 2, 4, 5.6, 8, 11.2, 16,22.4, 31.5, 45, and 63.EN 13043Base series +series 2mmSeries of sieves containing the following dor D dimensions: 0, 1, 2, 4, 6.3, 8, 10, 12.5,14, 16, 20, 31.5, 40, and 63.EN 13043It is common touse this series forFrenchbituminousmixtures.Binder coursePart of pavement between the surfacecourse and the baseEN 13108 seriesBitumenA highly viscous or almost solid material,which remains nearly non-volatile,adhesive and water repellent; it is derivedfrom crude oil or present in the form ofnatural bitumen, which is entirely or almostentirely soluble in toluene.EN 12597BituminousmasticA mixture of filler and a bituminous binder.BituminousmortarBulk densityρ bdimMVa g/cm 3orkg/m 3ρ bseag/cm 3MVA orkg/m 3ρ bγg/cm 3orMixture of fine aggregate 0/2 or all-in 0/4and a bituminous binder.Ratio of the mass of a test specimen to thespecimen volume. The volume may bemeasured by means of geometric methodsρ bdim [bulk by dimension] , in which caseMVa is obtained, or by hydrostatic methodsρ bsea [Bulk sealed ](EN 12697-6) yieldingMVA.EN Standardρ bsea(Bulk sealed)ρ bdim(Bulk by dimension)ρIn the laboratory, the bulk density is bγ(Bulk gamma)measured in some cases on the gamma- 178 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentsMVaγorkg/m 3measured in some cases on the gammadensitometer bench (EN 12697-7), whichyields ρ bγ or MVaγ.CalculatedmaximumdensityMVRc g/cm 3orkg/m 3MVR, obtained by means of calculationbased on the mass densities of theindividual components.ρ mc(maximal calculated)Cement Hydraulic binder composed of finelymoldedinorganic matter which, oncemixed with water, forms a paste that setsand hardens subsequent to hydrationreaction and process and which afterhardening retains both its strength andstability even underwater.CoarseaggregateDesignation given to the larger aggregatesize which D is less than or equal to45 mm and d greater than or equal to2 mm.EN 13043CoatedchippingsCoarse aggregate with a tight granulardistribution designed to be embedded intoa support matrix of an asphalt layer(NF P 98-133).Nominally single size aggregate particleswith a high resistance to polishing, whichare coated with high viscosity binder. Thechippings are always rolled into and form apart of hot rolled asphalt surface course.EN 13108-4Compacity C % Ratio of the test specimen volume inexcluding voids to the total specimenvolume.ComplementarytestTest added to the testing program for theparticular level. This complementaryassessment may be chosen from a highertest level or consist of a test related to aspecific technique or for a specific- 179 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentspurpose.Compressivestrength afterimmersionI MPa Compressive strength following immersion,as per EN 12697-12 Method B(corresponding to Duriez test (NF P 98-251-1)).In the Duriez testthe compressionstrength afterimmersion wasexpressed as “r”Compressivestrength withoutimmersionCMPa Compressive strength without immersion,as per EN 12697-12 Method B(corresponding to Duriez test (NF P 98-251-1)).In the Duriez testthe compressionstrength withoutimmersion wasexpressed as “R”ConnectingvoidsVoids in a test specimen that enable a fluidto cross from one face to the other.Content ofadditives(excludingadhesionagents)% ext. Mass of additives as a ratio of the dryaggregate mass.NF P 98-149Content ofadditives(excludingadhesionagents)% int. Mass of additive as a ratio of the mixturemass.Conventionalspecific surfaceareaΣm 2 /kg Determined by the following relation:100 Σ = 0,25 G + 2,3 S + 12 s + 150 f, with:G proportion of elements larger than6,3 mm,S proportion of elements lying between6,3 mm and 0,250 mm in size,s proportion of elements between0,250 mm and 0,063 mmf proportion of elements smaller than0,063 mmThis calculation isnot applicablewhen the mixturecontains eitherspecial fillers oradditives, suchas fibers.Correctioncoefficient forbinder contentα Mg/m 3 α = 2,650 / ρ dwhere ρ dis the mean particledensity of aggregate, in Mg/m 3 , determinedaccording to EN 1097-6.EN 13108 seriesSeveral methodsare described inEN 1097-6. ρ dshould be- 180 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentsinterpretedCourseStructural element of a pavementconstructed with a single material. Acourse may be laid in one or more layers.EN 13108 seriesCrushing index IC % Percentage of elements larger than D inthe resultant aggregate contained in theoriginal material submitted to crushing.Crushing ratio RC - Ratio of the smallest dimension in theoriginal coarse aggregate, submitted to theinitial crushing, to the D value of theresultant aggregate.Former definition.See angularity.Definitioncorresponding toa standard sincerescinded, yetstill used inbibliographicalreferences. Seeangularity.Delta ring andball temperature∆ R&B°C Stiffening power of a filler, as measured bythe difference in ring and ball temperatureobtained on a bitumen and masticcomposed by the tested filler and bitumen,as per Standard EN 13179-1.EN 13043Typical values:∆ R&B 8/16∆ R&B 8/25∆TBA∆TBA is the French transcription of ∆ R&BDry fillerporosityDynamicmodulusSee description under Rigden Voids Index.E(θ, f) MPa Standard for the complex modulus,expressed in MPa, as obtained at atemperature θ in °C and for a frequency fin Hz (EN Standard EN 12697-26, seeAppendix A).EmpiricalapproachA specifications method currentlyemployed in EN standards that consists ofcompositional recipes (particle sizedistribution curve, nature and content ofbinder, nature and rate of additives),aggregate characteristics, a general bodyof tests (percentage of voids, waterresistance, wheel tracking) and "empirical"tests (or performance-based testing), suchas Marshall stability and percentage ofvoids after 10 gyrations on the gyratorySeriesEN 13108All standards inthe series containan empiricalapproach- 181 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentscompactor.Bitumen withanti-strippingagentBitumen containing an adhesion or antistrippingagent.NF P 98-149External bindercontentTL ext% ext. Ratio of the binder mass to the dryaggregate mass.Use of the ppcnotation todesignate theunits of thismagnitude iserroneous.Fatigueresistanceε 6 µdef Deformation admissible at 10 6 cycles,according to the fatigue test result inEN 12697-24, Annex A, usually at 10°Cand 25 Hz.Filler aggregateAn aggregate whose grains pass the0,063-mm sieve and that can be added toconstruction materials to provide them withcertain characteristics.EN 13043Fine aggregate Designation of small-sized granularcategories, for which D is less than orequal to 2 mm and whose non-passingrate through the 0,063 mm remains high.EN 13043FinesParticle size fraction of an aggregate whichpasses the 0,063 mm sieve.EN 13043Fines content (ortotal finescontent) of themixtureTf % % passing the 0,063-mm sieve.Flakiness FI The shape of coarse aggregate isdetermined in terms of the flakiness index.FI 25 is the generally retained category. Forvery thin layers intended mixtures,category FI 20 may be necessary.Formula of amixture (or theDescription of a unique mixture on which amix design test has been performed. The- 182 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentsnominal formula,target formula ortheoreticalformula)formula comprises the mass compositionof all mix components, their origin, aparticle size distribution curve and theresults of tests conducted on arepresentative sample.FormulaverificationAssessment comprising a test or series oftests conducted on a mix design withcomponents of the same origin (e.g. sameextraction site, same crushing/screeningfacility) as the design to be verified, ascharacterized in particular by a particlesize distribution curve and binder content.FundamentalapproachA specifications method currentlyemployed in European standards thatconsists of compositional indications(potentially a particle size distribution range[rather broad], potentially the type of binderand additives), aggregate characteristics, ageneral body of tests (percentage of voids,water resistance, wheel tracking), andother "fundamental" tests, such as stiffnessmodulus, fatigue resistance and repeatedcompression.SeriesEN 13108.Only applicableto asphalt mixes(EN 13108-1)and Hot RolledAsphalt(EN 13108-4)Gap-gradedgrading curveAbsence of one or several intermediatefractions within a granular recomposition.Grading analysisSee Particle size distributionGradingcharacteristicsof coarseaggregateG C 85/20G C 85/20, category of d/D fraction definedby:• passing to D sieve between 85% and 99 %EN 13043• passing to d sieve between 0% and 20 %• 100 % to 2 D sieve• 0 % to 5 % to d/2 sieve.- 183 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentsG C 85/15G C 85/15 category defined by: passing to dsieve between 0 % and 15 %, instead of 20% and for single size coarse aggregateD/d, where D/d < 2, which is the case forgap-graded mixtures used in surfacecourse, passing to D sieve between 90 %and 99 %, 100 % to 2 D sieve, 0 % to 5 %to d/2 sieve]EN 13043Generallyrequired for gapgradedmixturesG 25/15G 20/15G 25/15 category of a fraction d/D is definedby a percentage passing at mid-size sieve[D/1,4], between 25 % and 80 % andG 20/15 is defined by a percentage passing atmid-size sieve between 20% and 70%,with in both cases, a tolerance on thetypical grading of ± 15 %, declared by theproducer.EN 13043f 1f 0,5The fines content of coarse aggregate ismeasured by the percentage of passing at0,063 mm sieve. Category f 1 means ≤ 1 %at 0,063 mm sieve and category f 0,5 means≤ 0,5 % at 0,063 mm sieve.EN 13043Gradingcharacteristicsof fine aggregateG F 85 G F 85 category of fine aggregates 0/2which is defined by:G TC 10• 100% passing at the 4 mm sieve• between 85% and 99% at the 2 mmsieve.G TC 10 Tolerances applied to the particlesize distribution of fine aggregate definedby:• ± 5% at D,• ± 10% at D/2,• ± 3% at 0,063 mm.f 16f 22Fines content category from fine aggregatewhich corresponds respectively to a finecontent of 16% or 22%.- 184 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentsGradingcharacteristicsof all inaggregateG A 85Category of all in aggregate with followingcharacteristics:• passing 100% at 2D,• 98 to 100% at 1,4D,• 85 to 99% at D.G TC 10G TC 10 Tolerances applied to the particlesize distribution of all in aggregate definedby:• ±5% at D,• ±10% at D/2,• ±3% at 0,063 mm.GranularcompacityC g % Ratio, expressed as a percentage, of theaggregate volume within a bituminousmixture to the total specimen volume.Grave-BitumeAC-GBBituminous mixture, as per EN 13108-1,designed to yield lower and upper basecourses with a thickness between 8 cmand 16 cm. AC-GB are classified into 4categories. They are relevant either of theempirical approach (Essentially AC-GB1,AC-GB2 and AC-GB3) or the fundamentalapproach (Essentially AC-GB2, AC-GB3and AC-GB4).Hard pavinggrade bitumenBitumen output from refining to a gradelower than paving bitumen (


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentsHigh-modulusbituminousmixtureAC-EMEHigh-modulus (stiff) bituminous mixture, inaccordance with EN 13108-1. This materialis used for base courses and is relevantfrom “fundamental approach”Hot RolledAsphaltHRADense, gap-graded bituminous mixture inwhich the mortar of fine aggregate, fillerand high viscosity binder are majorcontributors to the performance of the laidmaterial. The proportion of fine aggregateis high (on the order of 50%), while thefines content stands at approximately 9%;coarse aggregates only represent 30% ofthe total mixture. The bitumen content lieson the order of 7% to 8%. The percentageof voids is very low; when used on wearingcourses, this material is chipped with 10/16or 10/20 coarse aggregates.EN 13108-4HydrocarbonbinderA generic term used to designate anadhesive material containing bitumen, taror both.EN 12597Input targetcompositionExpression of a mix formulation in terms ofthe constituent materials, the grading curveand the percentage of bitumen added tothe mixture. This will usually be the resultof a laboratory mix design and validation.The French approach is usually based onthe “Input target composition”EN 13108 seriesInternal bindercontentBtl intTl%(int.)Ratio of the binder mass to total mixturemass. It is expressed as B in EN versionas tl int in some French standards and as Tlin the French version of the EN standards.The EN asphaltmix "product"standards fromthe EN 13108series dictate theB (tl Int ) value.LayerElement of pavement laid in a singleoperation.EN 13108 seriesLimeMaterial comprising any physical andchemical forms under which calciumand/or magnesium oxide and/or hydroxidecan appear.EN 459-1- 186 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentsAir limeLimes mainly consisting of calcium oxide orhydroxide which slowly harden in air byreacting with atmospheric carbon dioxide.Generally they do not harden under wateras they have no hydraulic properties. Theymay be either quicklimes or hydratedlimes.Loss of linearity Γ - Relative decrease in modulus of abituminous mixture as the yield strengthincreases. This determination is a specialaspect of the direct tensile test described inStandard NF P 98-260-1, which has notbeen included in the European StandardEN 12697-26. The test is conducted at 0°Cand the specimen is submitted tosuccessive tensile forces for 30-secondload times (and then reset to zero). Thedeformation rises from 50 10 -6 to 500 10 -6 .Loss of linearity is the relative drop inmodulus value at a deformation of 500 10 -6as a ratio of the modulus decreaseobtained at zero deformation. The modulusat zero deformation can be obtained bymeans of extrapolation.The loss oflinearity providesan indication onthe state ofmaterial damage.Lower thermalsusceptibilitybitumenA special bitumen, whose ring and balltemperature is higher than that of thecorresponding paving grade bitumen.ManufacturedaggregateAn aggregate of mineral origin resultingfrom an industrial process involvingthermal or other modifications.EN 13043Maximumdensityρ mvMVRg/cm 3orkg/m 3orMg/m 3ρ mvRatio of the mass of a test specimen to its (maximal density byabsolute volume, i.e. without incorporating volumetric procedure)the voids. Maximum density is determinedaccording EN 12697-5, Method A usingwater.Mix designProcedure consisting of adjusting, using aminimum number of tests, the compositionof a formula so that it is able to satisfy alldesign testing requirements and ultimatelyother requirements as well.- 187 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentsMix formulationComposition of a single mixture expressedas target composition. It may be expressedas “input target composition” or as “outputtarget composition”EN 13108 seriesMixed fillerFiller of a mineral origin mixed calciumhydroxide.EN 13043NaturalaggregateAn aggregate from mineral source whichhas been subjected to nothing more thantransformation other than mechanical.EN 13043Non-connectingvoidsVoids in a test specimen open at one face,yet unable to reach the other face.Noxiouspotential of finesSee harmfulness of fine aggregates.Occluded voidsVoids in the test specimen that do not openonto any of the specimen faces.Output targetcompositionExpression of a mix formulation in terms ofthe constituent materials and the mid pointgrading and soluble binder content to befound on analysis. This will usually be theresult of a production validation.EN 13108 seriesParticle sizedistribution orgrading analysisPavement% The dimensional distribution of grain sizes,expressed in terms of mass percentagepassing through a specified series ofsieves. The analysis is carried out inaccordance with EN 933-1 for aggregatesin general and with EN 12697-2 foraggregates stemming from strippingoperations.Structure, composed of one or morecourses, to assist passage of traffic overterrain.EN 13043EN 13108 series- 188 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentsPaving bitumenBitumen used to coat mineral aggregate foruse in the construction and maintenance ofpaved surface. In Europe, the most usedgrades are defined by needle penetrationat 25°C, up to a value of 900 1/10 mm.EN 12597Percentage oflaboratory voidscharacteristic ofthe bituminousmixturePVL % Value deduced by the mix designer, basedon void percentages measured on the testspecimens produced in the laboratoryusing various means of compaction.Percentage ofvoidsv % The air void is the pocket between thebitumen coated aggregate particles in acompacted bituminous specimen. The airvoid content or percentage of voids is thevolume of the air voids in a bituminousspecimen, expressed as a percentage ofthe total volume of that specimen.EN 12697-8Percentage ofvoids filled bybitumenVFB % Binder volume as a ratio of total voidvolume in the granular skeleton, expressedas a percentage.EN 12697-8Percentage ofvoids in themineralaggregateVMA % Percentage of the pore and intersticevolume in the granular skeleton as a ratioof total specimen volume. This valueincludes the percentage of voids in themixture and the percentage volumeoccupied by the binder.EN 12697-8PigmentablebitumenA special bitumen category characterizedby a low asphaltene content, whichfacilitates the coloration of asphalt mixesthrough adding pigments.EN 12597PolymermodifiedbitumenBmPModified bitumen materials are bituminousbinders whose properties have beenaltered through the use of a chemicalagent, which when introduced into theEN 14023- 189 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentsbasic bitumen modifies the chemicalstructure and the physical and mechanicalproperties.These bitumens are prepared prior toapplication within a specialized unit. Thechemical agents employed include naturalrubber, synthetic polymers, sulfur andcertain organic-metallic compounds; theydo not include oxygen, oxidation catalysts,fibers, mineral powders or adhesionagents.Porous asphaltPA-BBDrPorous asphalt, in accordance withEN 13108-7.Bituminous mixture in accordance withEN 13108-7, characterized by apercentage of voids exceeding or equal to20% and a void shape such that rainwateris able to circulate into the connectingvoids; this material is designed to yieldsurface courses with an average thicknessof 3-4 cm (PA6) and 4-5 cm (PA10).Pure bitumenConventional bitumen obtained by meansof various refining processes using crudeoil as a base. No additive is included forthe purpose of modifying the material'sconsistency.NF P 98-149ReclaimedasphaltRA orAEGranular materials stemming from eitherthe milling or demolition of asphalt mixesand entering into the composition ofrecycled mixes.NF P 98-149EN 13108-8RecycledaggregateAn aggregate resulting from processing ofinorganic materials previously used inconstruction.EN 13043RegulatingcourseCourse of variable thickness applied to anexisting course to provide the necessaryprofile for a further course of consistentthickness.EN 13108 seriesRepeatabilityReliability of measures under conditions ofrepeatability, i.e.: conditions according toISO 5725- 190 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentswhich the results of independent tests areobtained using the same method onidentical test specimens, in the samelaboratory, by the same operator, inemploying the same equipment and over ashort span of time.RepeatabilitylimitrValue below which the absolute value ofthe difference between two test results lies,with 95% probability, as obtainedaccording to repeatability conditions.ReproducibilityReliability of measures under conditions ofreproducibility, i.e.: conditions according towhich test results are obtained using thesame method on identical test specimens,in different laboratories, by differentoperators, in employing differentequipment.ISO 5725ReproducibilitylimitRValue below which the absolute value ofthe difference between two test results lies,with 95% probability, as obtainedaccording to reproducibility conditions.Richness modulusConventionalspecific surfaceareaΣm 2 /kg Determined by the following relation:100 Σ = 0,25 G + 2,3 S + 12 s + 150 f, with:G proportion of elements larger than6,3 mm,S proportion of elements lying between6,3 mm and 0,250 mm in size,s proportion of elements between0,250 mm and 0,063 mmf proportion of elements smaller than0,063 mmThis calculation isnot applicablewhen the mixturecontains eitherspecial fines oradditives, suchas fibers.Richness modulusCorrectioncoefficientα α = 2,65 / ρ Gwith ρ Gbeing the aggregatemass density in terms of grams per cubiccentimeter.This coefficient isemployed inparticular tocalculate bitumencontents on thebasis of therichnessmodulus.- 191 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentsRichnessmodulusK A magnitude proportional to theconventional thickness of the bituminousbinder film coating the aggregate. K isindependent of the granular mix densityand well correlated with binder content bythe following equation:TL = K × α 5Σwhere Σ is the conventional specificsurface area,α a correction coefficientRigden: Void ofdry compactedfillerVDetermination of the percentage of voids ina filler compacted by (100) shocks in acylinder.EN 13043Typical values:Test standard: EN 1097-4.V 28/45Ring and balltemperature°C Two bitumen disks, molded into brassrings with shoulders, are heated in a liquidsolution at a controlled rate of temperaturerise, with each supporting a steel ball. Theobserved softening temperature mustcorrespond to the average temperature atwhich the two disks are softening enoughto allow each bitumen-coated ball to fallfrom a height of 25,0 mm ± 0,4 mm.EN 1427Secant modulus E(θ, t) MPa Modulus obtained at a temperature θ in °Cand for a load time of t in seconds(European Standard EN 12697-26, seeAppendix E).AsphaltConcrete –BétonBitumineuxSemi-GrenuAC-BBSGBituminous mix, in accordance withEN 13108-1, characterized by a highcoarse aggregate content and designed toyield surface or binder courses with athickness between 5 cm and 9 cm.« Semi-coarseasphaltconcrete »SensitivityanalysisAn optional experimental design,prescribed on certain composition variantsor percentage of void deviations in order tocharacterize mixtures that deviate from thenominal composition or that displaydifferent percentages of voids.- 192 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentsShape of coarseaggregateFISee Flakiness IndexLowerdimension of agranular fractionor bituminousmixtureSoft bitumend mm Dimension, chosen in the base series +series 1 or + series 2, corresponding to thegrain size determined with a particle sizedistribution analysis by means of sieving,such that the majority of grains do notpass. This definition acknowledges thatgrains are capable of passing the sieve ofdimension d, according to the categoriesand within the limitations prescribed inStandard EN 13043. Conditions areimposed upon the sieve with opening d/2.Paving bitumen used in the manufacture ofsoft asphalt. In Europe, grades of softbitumen are defined by their viscosity at60°C.Standardpenetration of abituminousbinder0,1mmConsistency corresponding to the verticalpenetration of a reference needle in amaterial test sample, under a set ofprescribed conditions on temperature, loadand load application time. The standardpenetration corresponds to a temperatureof 25°C, a load of 100 g and an applicationtime of 5 s.EN 1426This test servesto categorizebitumen types,especially inEN 12591, e.g.35/50 vs. 50/70.StiffnessmodulusStone masticasphaltE MPa Ratio of the stress at a relative deformationsubmitted to a specimen during amechanical test. This value serves tocharacterize the level of material stiffness.For bituminous materials, the stiffnessmodulus value must be accompanied bythe temperature and loading time orfrequency during the test period.SMA Gap-graded mixture with bitumen asbinder, composed of a coarse crushedaggregate skeleton bound with a masticmortar. Mixture with a particle size rangelying between 0/4 and 0/20, characterizedby a high proportion of coarse aggregatesand mastic. Bitumen content is also high;fibers are incorporated, if need be todecrease the risks of drainage.EN 13108-5- 193 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentsSurface courseUpper course of a pavement which is incontact with the traffic.EN 13108 seriesSynthetic binderA binder obtained by mixing petroleum andpetrochemical fractions without anyasphaltene. This binder appears as a thintransparent film, which makes it possible toretain the natural hue of the aggregate;moreover, it can be colored by addingpigments.Thin layerasphalt concreteAC-BBMBituminous mix, in accordance withEN 13108-1, characterized by an averageapplication thickness of between 3 and5 cm; material intended to yield limitedthickness surface (or binder) layers.Category A is 2/6 gap-graded, Category Bis 2/4 gap-graded, Category C iscontinuously graded.The particle sizedistributioncurve is mostoften gapgraded.Type testingPredefined sequence of laboratory testsconducted on a given composition mixturefor the purpose of determiningcharacteristics that satisfy a set ofestablished requirements.Type testingLevel 0Assessment containing a description of themix without further testingType testingLevel 1Assessment featuring both a GyratoryCompaction test for determination of thevoid content and a water-sensitivity testaccording EN 12697-12, method B,specimen preparation in compression.Type testingLevel 2Assessment containing all of the Level 1tests plus a wheel tracking test (largedevice).Type testingLevel 3Assessment containing all Level 2 testsplus stiffness modulus tests.Type testingLevel 4Assessment containing all Level 3 testsplus a fatigue test (EN 12697-24-Annex A).Upper dimensionof an aggregateor bituminousD mm Sieve dimension, as chosen in the baseseries + series 1 or + series 2,corresponding to the grain size determined- 194 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentsmixturewith a particle size distribution analysisanalyze by means of sieving, such that themajority of grains pass (between 85% and99% depending on the specific case). Thisdefinition acknowledges that grains arecapable of not passing the sieve ofdimension D, according to the categoriesand within the limitations prescribed inStandard EN 13043. Conditions areimposed upon the sieve of opening 1,4 D.BétonBitumineux TrèsMinceVery thin layerasphalt concreteBBTMBituminous mix, in accordance with EN13108-2, characterized by an averageapplication thickness of between 2 and3 cm; material intended to yield surfacecourses.Void of drycompacted fillerRigdenVDetermination of the percentage of voids ina filler compacted by (100) shocks in acylinder.Test standard: EN 1097-4.EN 13043Typical values:V 28/45Volume ofabsorbedbitumenvbaVolume of bitumen penetrating into theaggregate pores.Warm asphaltSpecific process intended to reduce themixing and the compaction temperature ofthe bituminous mixture withoutcompromising the characteristics of themixture. The lower mixing temperature isobtained by decreasing the viscosity of thebinder using for example special binderwith a wax addition, double coating (softand hard grade bitumen), addition offoaming agent, presence of water due tospecific additives or to wet coldconstituents in order to have a foamingeffect on the binder.Half warmasphaltIf the mixture is produced at a temperaturebelow 100°C, it is considered as “Halfwarm asphalt”.- 195 -


LPC Bituminous Mixtures Design Guide– Appendix G - Glossary –TermSymbol orAbbreviationUnitDefinitionCommentsZeoliteCrystalline hydrated aluminium silicate,which contains part of water. When it isadded to the mix at the same time as thebitumen, water is released and creates anbitumen foam which allows increasedworkability. Used as additive for WarmAsphalt technology.- 196 -


LPC Bituminous Mixtures Design Guide- Index -IndexAAC-BBME, 44, 47, 56, 59, 60, 61, 64, 80,90, 91, 101, 111, 115, 185AC-BBS, 43, 44, 47, 64, 91, 177AC-BBSG, 41, 44, 47, 56, 59, 60, 61, 64,75, 77, 80, 90, 91, 103, 104, 110, 111,113, 115, 128, 140, 164, 185, 192AC-EME, 41, 43, 47, 56, 59, 60, 61, 62,64, 86, 87, 88, 101, 106, 111, 115, 116,117, 125, 139, 140, 186AC-GB, 41, 47, 59, 60, 61, 64, 75, 85, 86,88, 103, 104, 115, 128, 139, 140, 185added filler, 26, 43, 55, 73, 74additive, 25additives, 35, 41, 48, 73, 74, 81, 82, 85,86, 91, 93, 96, 100, 114additives, 30airfields, 44, 52, 66, 149Bbasalt, 26, 49, 85, 90, 128binder content, 5, 17, 19, 21, 34, 37, 39,40, 50, 51, 52, 53, 54, 56, 57, 64, 66,75, 85, 86, 87, 88, 90, 92, 94, 95, 97,98, 99, 100, 102, 105, 111, 113, 116,124, 127, 131, 151, 154, 156, 157, 164,166, 167, 168, 169, 170, 171, 172, 180,182, 183, 186, 188, 192bitumen, 18, 20, 27, 28, 29, 30, 31, 32, 35,36, 38, 39, 40, 48, 49, 52, 54, 55, 62,64, 66, 67, 68, 69, 70, 75, 77, 78, 79,80, 81, 82, 83, 84, 85, 86, 87, 89, 91,93, 95, 96, 99, 100, 101, 104, 105, 106,110, 111, 113, 114, 115, 116, 117, 118,120, 121, 122, 124, 128, 134, 140, 150,154, 155, 164, 166, 167, 168, 169, 170,171, 172, 177, 178, 181, 182, 185, 186,187, 189, 190, 191, 192, 193, 195, 196bulk density, 37, 38, 40, 54, 62, 64, 66, 67,68, 69, 70, 130, 151, 154, 178compacity, 22, 35, 38, 55, 75, 77, 78, 86,101, 103, 104, 105, 106, 110, 113, 115,116, 120, 122, 160, 185Ddrainage, 62, 69, 71, 74, 82, 93, 114, 123,153, 155, 193Duriez, 145EME, 145EFfatigue, 4, 14, 15, 17, 18, 19, 20, 25, 35,55, 56, 61, 65, 79, 82, 83, 84, 101, 117,121, 122, 124, 125, 127, 131, 140, 141,142, 144, 145, 146, 152, 156, 174, 177,182, 183, 194fibres, 35filler, 5, 26, 32, 36, 42, 43, 55, 74, 75, 82,86, 101, 150, 164, 165, 166, 167, 168,169, 170, 171, 172, 173, 174, 175, 178,181, 186, 188, 192, 195fine aggregate, 43, 44, 64, 75, 76, 77, 79,85, 90, 101, 102, 109, 110, 113, 114,115, 123, 124, 178, 184, 186Fine content, 164, 165, 166, 167, 168,169, 170, 171, 172, 173, 174fines, 5, 26, 30, 35, 41, 42, 43, 44, 73, 74,75, 76, 78, 82, 85, 90, 102, 104, 106,107, 110, 113, 115, 124, 149, 182, 184,185, 186, 188, 191fly ash, 26, 74GGrave-Bitume, 41, 85, 86, 87, 103, 185graves-bitumes, 146gyratory, 5, 15, 19, 20, 22, 35, 53, 55, 102,103, 105, 114, 127, 142, 152, 154, 157,170, 171, 181cement, 26, 49, 74color, 82, 175, 107CII/C, 74, 75, 86, 90, 93, 114, 115, 116, 164,165, 166, 167, 168, 169, 170, 171, 172,173, 174- 197 -


LPC Bituminous Mixtures Design Guide– Index –indirect tensile, 22, 55, 156Llimestone, 26, 30, 32, 74, 77, 85, 86, 90,115, 176, 177MMarshall, 18, 19, 64, 65, 66, 152, 156,157, 181mastic, 19, 36, 74, 75, 101, 123, 153, 178,181, 193maximum density, 37, 53, 54, 63, 64, 66,67, 69, 70, 77, 87, 92, 94, 97, 99, 105,151, 154, 157, 160, 179module, 144, 145, 146module de rigidité, 144, 145MVR, 37, 38, 39, 53, 54, 64, 66, 67, 68,70, 77, 87, 92, 94, 97, 99, 105, 160,179, 187natural asphalt, 49oxides, 29, 33PPCG, 146penetrability, 28, 29, 30, 48, 83permeability, 62, 71, 153, 155PmT, 123polymer, 28, 48, 80, 91, 93, 96, 151, 154polymer modified, 151, 154polymères, 144porous, 37, 50, 62, 70, 74, 96, 101, 152,155Porous Asphalt, 46, 92, 93, 95, 123NOPresse à Cisaillement Giratoire, 145, 146pseudo shear stress, 105RResistance to deicing products, 66, 67, 68,69, 71Resistance to fuels, 66Richness modulus, 191, 192ring and ball, 28, 29, 30, 32, 48, 80, 83,86, 113, 150, 164, 165, 166, 167, 168,169, 170, 171, 172, 173, 174, 181, 187rubber, 27, 28, 29, 31, 82, 189Sslope, 83, 102, 104SMA, 82, 98, 99, 123, 193stiffness, 4, 15, 19, 20, 23, 28, 55, 56, 60,61, 62, 65, 79, 81, 83, 84, 86, 89, 101,116, 118, 119, 120, 122, 124, 125, 127,131, 136, 137, 139, 140, 142, 165, 173,174, 177, 183, 185, 193, 194Synthetic binders, 81Ttype testing, 18, 19, 20, 33, 41, 42, 44, 54,56, 57, 60, 62, 63, 64, 66, 73, 79, 102,153, 154Wwater resistance, 19, 22, 35, 55, 57, 59,60, 61, 63, 74, 79, 83, 85, 86, 90, 93,101, 109, 114, 115, 124, 181, 183water sensitivity, 152, 155wheel tracking, 23, 44, 55, 56, 58, 60, 61,62, 65, 76, 78, 79, 85, 89, 110, 132,133, 134, 135, 172, 181, 183, 194- 198 -

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