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

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costs, extended testing time, lack of aging protocols, and the need for a residue recovery method that yields a binder consistency equal to that of a pavement-cured material. More importantly, there is little consensus regarding the definition of performance parameters and specific testing conditions for PME chip seal and PME microsurfacing/slurry applications. Unfortunately, current practice is only loosely tied to variability in climate and traffic. For example, the penetration range for a binder in current microsurfacing specifications is 40 to 90 dmm, a range that would typically represent three full grades in the PG grading system for HMA binders (i.e., PG 58, PG 64, & PG 70). Implementation of performance specifications is a huge data gap. Virtually every expert believes it should be done, but no one knows how. • Basic Requirements and Preferred Outcomes for Residue Testing: Although many issues remain to be resolved before asphalt emulsion residues can be characterized with reliable performance tests, a number of guidelines for future research can be established based on input received during the survey and related discussions: 1. Residue performance properties to be characterized: • High temperature grade based upon climate, traffic, and appropriate failure parameters (rutting, bleeding) • Low temperature grade based upon climate and appropriate failure parameters (cracking, aggregate loss) • Polymer identifier which is able to rank performance at different levels of polymer modification • High Float gel identifier • Aging Protocol: RTFO was definitively rejected, since hot mix plants are not used for cold emulsion applications. The Pressure Aging Vessel (PAV) is clearly the aging tool of choice, but has a number of limitations as described below. 83
• Polymer/Asphalt Compatibility and Stability During Aging: It is known that certain polymer/asphalt blends are incompatible, such that the polymer will tend to separate or loose its elastic network over time. For modified HMA binders, such unstable systems are typically eliminated by specifying heat stability tests such as the Long-Term Asphalt Stability (LAST) test or the Separation Test. Because there is no heated storage of emulsion residue, experts reject these methods as performance indicators. Another good indication of compatibility comes from various microscopic methods such as fluorescence or scanning electron microscopy. Again, experts suggest such methods are useful to the formulator, but should not be adopted for specifications. As another data gap, a method is needed to insure polymer network stability under the conditions experienced by aging emulsion residues on the pavement surface. 2. PME residues should not be exposed to elevated temperatures during recovery or sample preparation. Any procedure requiring curing or reheating temperatures above 60ºC (140°F) must be validated by showing performance properties comparable to those from Forced Draft Oven Residues. 3. Minimize the quantity of residue needed for performance testing, ideally completing all residue tests with the recovered binder from a single silicone mold as cured in the Forced Draft Oven Recovery Method. 4. Minimize equipment costs and testing time, using common tools wherever possible. Survey comments and AEMA discussions emphasized the concern that there are many small companies supplying emulsion from one or two plants, and those facilities only manufacture approximately 10- 20% of volumes shipped by refineries or liquid asphalt terminals supplying 84
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Using Polymer Modified Asphalt Emul
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2.10 SURFACE TREATMENTS, DISTRESS,
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EXECUTIVE SUMMARY Needs to be Compl
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DISCLAIMER This document is dissemi
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1. Compile published research on th
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2.0 LITERATURE REVIEW OF POLYMER MO
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the emulsion solution is termed the
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molecular weights ranging up to 100
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Elastomeric polymers exhibit a low
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The first commercial process that w
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2.2.3 Synthetic Rubber and Latex Sy
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Latex Modified Unmodified 80 Chip R
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of residual asphalt (3). Additional
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Sabbagh and Lesser (1998) note that
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2.2.6 Plastics The plastic polymer
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high temperature performance, but w
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2.2.7 Polymer Blends Select polymer
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Table 2: Polymer Modification Metho
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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: were consistently twice as high as
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 and 100: conforming to the following criteri
Page 101 and 102: with faster curing and longer wear.
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, “
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Using Polymer Modified Asphalt Emulsions in Surface Treatments A ...

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