Using Polymer Modified Asphalt Emulsions in Surface Treatments A ...

More documents

Recommendations

Info

Table 15: TxDOT Aggregate Gradation Requirements (Cumulative % Retained 1 ) Grade Sieve 3 Size 1 2 3S2 Nonlightweight 4S2 4 5S2 5 Lightweight 1" – – – – – – – – – 7/8" 0–2 0 – – – – – – – 3/4" 20–35 0–2 0 0 0 – – – – 5/8" 85– 100 20–40 0–5 0–2 0–2 0 0 – – 1/2" – 80–100 55–85 20–40 10–25 0–5 0–5 0 0 3/8" 95– 100 95–100 95–100 80–100 60–80 60–85 20–40 0–5 0–5 1/4" – – – 95–100 95–100 – – 65–85 – #4 – – – – – 95–100 95–100 95–100 50–80 #8 99–100 99–100 99–100 99–100 98–100 98–100 98–100 98–100 98–100 1. Round test results to the nearest whole number. 2. Single-size gradation. Aggregate specifications for chip seals vary widely, and not all agencies differentiate aggregate quality for traffic. Even the definition of high-volume traffic for chip seals varies markedly, with experts somewhat arbitrarily choosing anywhere from 1,000 ADT to 10,000 ADT as a minimum level which might require higher quality materials. A high volume chip seal study by Shuler elected to construct field test sections with ADTs exceeding 7,500 ADT. Recommendations from that study, and the new NCHRP project also led by Shuler (Manual for Emulsion-Based Chip Seals for Pavement Preservation: NCHRP 14-17) should be considered. Since FLH has graciously agreed to support this latter NCHRP project with field trials, Shuler’s results and recommendations should be available and pertinent to FLH needs. Although the study is ongoing, Shuler has already made some recommendations to the FLH research team based upon earlier work. One example of note is to reduce the LA Abrasion maximum from 40% to 25% for high volume traffic. As another example, SemMaterials (formerly Koch Materials) developed a high performance chip seal system under the trademark RoadArmor® for higher volume traffic. This system includes a new piece of construction equipment which applies both emulsion and then aggregate in a single pass. It also includes upgraded emulsion and aggregate specification recommendations consistent 93
with faster curing and longer wear. RoadArmor® was actually developed for chip seal applications that need a quick return to traffic, a concept which may be more appropriate than ADT to FLH needs on pavements such as narrow mountain roads or isolated areas where detours are unavailable and traffic control is difficult. Hence, RoadArmor® guidelines do not define high volume traffic with a specific ADT. However, the aggregate guidelines supplied with this system offer some insight as to recent trends applicable to differentiating material quality. As can be seen on the comparative table for chip seal aggregates (Table 12), RoadArmor® guidelines reduce P-200 fines and deleterious materials and require more crushed faces than most agency specifications. Interestingly, this guideline specification also appears to be the first in the U.S. to replace LA Abrasion with Micro-Deval. Although the industry survey received more favorable votes for LA Abrasion, the respondents who actually had experience with using Micro-Deval to screen aggregate durability strongly favored it. Since FLH has the Micro-Deval apparatus available in the Denver lab, it is recommended that Micro-Deval be required in the report-only portion of the experimental materials testing plan. Results should be compared against the RoadArmor guideline of 17% maximum loss to determine whether similar limits might fit FLH needs on higher volume chip sealed pavements. • Aggregate specifications for PME microsurfacing/slurry: ISSA offers separate aggregate quality guidelines for slurry seal and microsurfacing applications. The industry survey indicated that ISSA guidelines represent best current practice, and should be adopted where possible as minimum requirements. More recent research for CALTRANS led by Fugro Consultants proposes that all slurry systems be redefined in essentially three categories based upon traffic, climate, and application. These three classifications should provide better definition for use of microsurfacing, Polymer 94
Page 1 and 2:
Using Polymer Modified Asphalt Emul
Page 3 and 4:
2.10 SURFACE TREATMENTS, DISTRESS,
Page 5 and 6:
EXECUTIVE SUMMARY Needs to be Compl
Page 7 and 8:
DISCLAIMER This document is dissemi
Page 9 and 10:
1. Compile published research on th
Page 11 and 12:
2.0 LITERATURE REVIEW OF POLYMER MO
Page 13 and 14:
the emulsion solution is termed the
Page 15 and 16:
molecular weights ranging up to 100
Page 17 and 18:
Elastomeric polymers exhibit a low
Page 19 and 20:
The first commercial process that w
Page 21 and 22:
2.2.3 Synthetic Rubber and Latex Sy
Page 23 and 24:
Latex Modified Unmodified 80 Chip R
Page 25 and 26:
of residual asphalt (3). Additional
Page 27 and 28:
Sabbagh and Lesser (1998) note that
Page 29 and 30:
2.2.6 Plastics The plastic polymer
Page 31 and 32:
high temperature performance, but w
Page 33 and 34:
2.2.7 Polymer Blends Select polymer
Page 35 and 36:
Table 2: Polymer Modification Metho
Page 37 and 38:
Forbes et al found that asphalt emu
Page 39 and 40:
Lubbers and Watson (2005) present t
Page 41 and 42:
Takamura and Heckmann (1999) sugges
Page 43 and 44:
Neat Asphalt + 8% LDPE1 + 8% LDPE2
Page 45 and 46:
Figure 16: Effect of SBS Concentrat
Page 47 and 48:
destruction of the polymer modifier
Page 49 and 50: emulsified and non-emulsified aspha
Page 51 and 52: However, in developing the SPG, Epp
Page 53 and 54: • Forced Air-Drying Method - This
Page 55 and 56: • Wet Track Abrasion Loss - used
Page 57 and 58: ductility (61). King characterizes
Page 59 and 60: Polymer modified asphalt emulsions
Page 61 and 62: 3 40-120º F 5.02 12.81 6.04 14.92
Page 63 and 64: emulsions require a much longer set
Page 65 and 66: Figure 20: Chip Seal Aggregate Rete
Page 67 and 68: design specifications are meticulou
Page 69 and 70: Holleran (n.d.) recommends using SB
Page 71 and 72: 22 20 18 Vertical Displacement (%)
Page 73 and 74: seal stone retention, and to provid
Page 75 and 76: Microsurfacing applications by defi
Page 77 and 78: Thus, the cohesive properties of SB
Page 79 and 80: dimensional polymer network is pres
Page 81 and 82: Moreover, although the moduli of th
Page 83 and 84: Numerous decision tools and best pr
Page 85 and 86: 3.0 LABORATORY TESTING AND SPECIFIC
Page 87 and 88: and performance-related specificati
Page 89 and 90: were consistently twice as high as
Page 91 and 92: • Polymer/Asphalt Compatibility a
Page 93 and 94: angle at the lowest pavement temper
Page 95 and 96: damaged by temperature. The problem
Page 97 and 98: Because the industry survey and oth
Page 99: conforming to the following criteri
Page 103 and 104: Table 17: Comparison of Microsurfac
Page 105 and 106: Emulsion/Aggregate Performance Test
Page 107 and 108: the FLH report-only format be used
Page 109 and 110: leading the negatives. If post-blen
Page 111 and 112: opportunity to evaluate performance
Page 113 and 114: traffic areas, as are durable, poli
Page 115 and 116: esearchers, with the leading candid
Page 117 and 118: Table 13 illustrates a draft Strawm
Page 119 and 120: Laboratory Design Procedures • Ch
Page 121 and 122: • Develop/improve performance met
Page 123 and 124: specification tests will cost appro
Page 125 and 126: PROPERTY TEST METHOD SPEC. RESULT B
Page 127 and 128: 14. Takamura, Koichi, “SBR Latice
Page 129 and 130: 38. Turk, Johannes, and Schmidt, Ma
Page 131 and 132: 62. Desmazes, C., Lecomte, M., Lesu
Page 133 and 134: 86. European Standard EN 14895, “
show all

Using Polymer Modified Asphalt Emulsions in Surface Treatments A ...

Create successful ePaper yourself

Delete template?

Save as template?