Comparison of 9.5 mm SuperPave and Marshall Wearing I Mixes in ...

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39CHAPTER 4 FINE AGGREGATE ANGULARITY TESTING4.1 INTRODUCTIONA major part of this research was analyzing the feasibility of using high percentages of naturalsand in mixes designed for low volume roads. Therefore, of Fine Aggregate Angularity (FAA)tests were conducted for blend ratios of 100:0, 75:25, 68:32, 50:50, 25:75, and 0:100, crushedlimestone sand to natural sand. These tests provided a baseline for evaluating the effect ofblending on the FAA of the combined sands.Evaluating the FAA of the actual blends used for the mix designs was the second part of the FAAtesting. Mix specific FAA tests were conducted after the appropriate design aggregate structurewas determined for each mix design. This ensured that the correct sand percentages would betested. The results of these tests were also used to determine if the developed mixes wouldmeet WVDOH Superpave specifications for FAA values for medium and heavy traffic levelroadways. The current minimum value for heavy traffic design in Superpave is 45% while thevalue for medium traffic level design is 40%. Low volume roads do not have Superpave a FAArequirement.4.2 SIGNIFICANCE AND USE OF FAA TESTSThe applicable standard for this test is AASHTO T 304-96, Uncompacted Void Content of FineAggregate (AASHTO, 2000). This test method outlines the procedure for determining theuncomplicated void content of a sample of fine aggregate. Results from this test on samples ofa known gradation provide an indication of the aggregate’s angularity, sphericity and surfacetexture when compared with other aggregates possessing the same gradation. This test canalso provide an indication into the effect of the fine aggregate on the workability of a mixture inwhich it may be used when the void content is measured on an as-received grading. Tests forthis research focused on determination of the physical characteristics of the fine aggregate.Three procedures, Methods A, B and C, are included in AASHTO T 304-96. Methods A and Bprovide percent void content determined under standardized conditions which will yield resultsthat depend on particle shape and texture of the fine aggregate. If the results, by theseprocedures, show an increase in void content then that indicates greater angularity, lesssphericity or rougher surface textures. A decrease in the void content value indicates a morerounded, spherical or smooth surfaced aggregate. Method C measures the uncompacted voidcontent of the minus 4.75-mm (#4) portion of an as-received material. Method A was theprocedure selected for testing the aggregate for this research since it is specified by WVDOH.4.3 FAA TEST METHOD AND PROCEDUREMethod A was selected as the test method to determine uncompacted void percentages for thisresearch (AASHTO T 304-96). The testing apparatus used for all methods of the FAA test isbasically a one-pint Mason jar without a bottom and a cone of standard volume attached to the
40mouth. This jar rests on a holder positioned over a 100 mL cylinder. The entire device is placedinside of a pan used to retain fine aggregate particles.Sampling for these tests was conducted according to ASTM D 75 and ASTM C 702 (ASTM, 2000).Washing, sieving and drying was done in accordance with ASTM C 117 and ASTM C 136. Oncethis was completed the sample was weighed out. Method A specifies proportions of fourdifferent aggregate sizes as:SieveWeight (g)#16 44#30 57#50 72#200 17Total 190The bulk dry specific gravity was also needed to complete the calculations for determining theuncompacted voids content. This was determined by taking a larger sample of the sameproportions shown above and testing them according to ASTM C 128, Standard Test Method forSpecific Gravity and Absorption of Fine Aggregate.The testing procedure began with mixing the test sample until it was homogeneous. The jar andfunnel were then placed in the stand and the 100 mL measure placed directly under the funnelopening. The sample was placed into the jar and leveled; a finger was placed at the tip of thefunnel to retain the sand. The finger was then removed and allowing the sample to fall freelyinto the measuring cylinder. After the funnel empties, excess fine aggregate was struck off thecylinder. The measure was then weighed to determine the mass of fine material contained inthe measure. This process was run twice for each mixture of fine material. The uncompactedvoid content is computed as:UFVGsb100 [4.1]VWhere,U = uncompacted voids, percent, of the material.V = volume of measure, mL,
Page 1 and 2: COMPARISON OF 9.5 MM SUPERPAVE ANDM
Page 3 and 4: iNOTICEThe contents of this report
Page 5 and 6: iiiasphalt concrete wearing courses
Page 7 and 8: vMixing Procedure 78Appendix B Fine
Page 9 and 10: viiTable C-7 Marshall Medium 13% NS
Page 13 and 14: 4Table 1.1 Mix Design Types in Expe
Page 15 and 16: 6CHAPTER 2 LITERATURE REVIEW2.1 INT
Page 17 and 18: 82. determine aggregate stockpile b
Page 19 and 20: 10SieveAllowable PercentPassing Sie
Page 21 and 22: 12Stability is recorded as the maxi
Page 23 and 24: 14The WVDOH procedure for determini
Page 25 and 26: 16sieve. This is somewhat different
Page 27 and 28: 18G sb = bulk specific gravity of a
Page 29 and 30: 20theoretical gravity at the initia
Page 31 and 32: 22D/B est = adjusted dust to binder
Page 33 and 34: 24P b,est - 0.5%,P b,est ,P b,est +
Page 35 and 36: Percent Passing261009080Superpave U
Page 37 and 38: 28Table 2.6 WVDOH Marshall and Supe
Page 39 and 40: 30Table 2.9 Habib Marshall Analysis
Page 41 and 42: 32theoretically correct in that the
Page 43 and 44: 34the machine. This variability was
Page 45 and 46: 36CHAPTER 3 EQUIPMENT3.1 INTRODUCTI
Page 47: 38Hose PressureWheel Load100 psi100
Page 51 and 52: problematic, as the saturated surfa
Page 53 and 54: 44Mechanical Laboratory Sieve. Afte
Page 55 and 56: Percent Passing4610090100% Limeston
Page 57 and 58: 48Maximum specific gravity is a req
Page 59 and 60: 50gradation. This allowed for direc
Page 61 and 62: Percent Passing521009080Light 100%
Page 63 and 64: 54percentage of aggregate from the
Page 65 and 66: 56Table 5.4 Summary of Volumetric a
Page 67 and 68: 58Table 5.5 Calculated and Adjusted
Page 69 and 70: 60Table 5.6 Results of APA TestsAir
Page 71 and 72: 62exhibit lower rut depths than any
Page 73 and 74: design had significantly more rutti
Page 75 and 76: 66SP L 100LS SP L 64NS -10.335 2.77
Page 77 and 78: 68percent air voids and percent lim
Page 79 and 80: Air Voids (%)Uncompacted Voids (%)7
Page 81 and 82: 72than the Marshall mixes. Table 6.
Page 83 and 84: Voids in the Mineral Aggregate. As
Page 85 and 86: 76REFERENCESAmerican Association of
Page 87 and 88: 78APPENDIX A BUCKET MIXER INSTRUCTI
Page 89 and 90: 80APPENDIX B FINE AGGREGATE ANGULAR
Page 91 and 92: 82Table B-3 Uncompacted Void Conten
Page 93 and 94: 84AGGREGATE DESIGN DATATable C-1 St
Page 95 and 96: 86Table C-3 Computed Blend Gradatio
Page 97 and 98: 88Table C-7 Marshall Medium 13% NS
Page 99 and 100:
90%G mm%AC VMA VTM VFA @ N ini @N d
Page 101 and 102:
92Table C-14 Superpave Light 64% NS
Page 103:
946 2979.3 1696.7 2988.1 2.307 7.09
Page 106 and 107:
971 2912.7 1620.8 2917.9 2.246 7.65
Page 108 and 109:
992 8.40 10.80 7.402 7.90 9.90 7.80
Page 110 and 111:
1011 9.50 6.90 11.502 9.79 7.15 10.
Page 112 and 113:
1032 8.55 5.20 5.95L R RDate Tested
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