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

More documents

Recommendations

Info

2.3 Polymer Modification Methods and Dosage Rates The performance of polymer modifiers can be greatly affected by the blending techniques that are utilized, the quantity that is added relative to residual asphalt content, the types of aggregate used, and the methods and temperatures of emulsion storage. This section provides discussions related to the impacts of mixing methodologies and conditions, dosing rates, and storage and handling practices on the demonstrable field and laboratory qualities of polymer modified asphalt emulsions. 2.3.1 Polymer Modification Methodology Table 2 presents a summary of representative polymer modification methods and recommended dosage rates by polymer type, which have been culled from the available literature. A review of Table 2 reveals that commonly utilized techniques generally include the pre-addition of polymer to either the emulsifying solution or asphalt; postaddition to the finished emulsion product; or “co-milling” of the various component streams at the colloid mill (see Figure 2). Moreover, of the recommended modification methods presented in Table 2, pre-mixing with the soap solution is the generally preferred method of adding liquid latex to asphalt emulsions, followed by co-milling at the colloid mill. Becker et al (2001) observe that the phase separation and stability problems associated with using solid polymer modifiers generally necessitates the use of a “hot mix” addition method in such cases, whereby the solid polymer is pre-blended with the asphalt prior to emulsification (7). Post-addition of the modifier to the final emulsion product either at the plant or the application site is sometimes discouraged due to the need for vigorous, continual, and thorough mixing to ensure proper and homogeneous polymer dispersal. One notable exception is the use of CRM-based RG-1, which is predigested with an organic solvent prior to being post-added to the emulsion. 27
Table 2: Polymer Modification Methods and Dosages Type Method % Polymer Solids Application(s) Reference(s) SBR Soap pre-batching. NO post or field addition. 3 – 4% of residual asphalt content. Slurry Seals (36) SBR Not Specified 3% of residual asphalt content Various (4) SBR (Ultracoat) Dilute with water to 15% latex solids and blend with aggregate at collection hopper. 15% of total emulsion weight Polymeric anti-strip coating to increase stone retention in chip seals. (37) SBR (Butonal LS 198®) Soap pre-batching. NO post or field addition. 2 - 6% of residual asphalt content, usually 3%. Various (9, 38) SBR Soap pre-batching. >=3% of residual asphalt content. Microsurfacing (39) SBR, NRL, Neoprene, SBS, EVA Pre-blend latex solids with bitumen using a high-shear blender. If latex in form, then use soap pre-batching. 2% of residual asphalt content. Microsurfacing (40) SBR, NRL Soap pre-batch, co-mill, or post add. 3 – 5% of residual asphalt content. Various. (41) SBS Pre-blend with asphalt. 5 – 12% of residual asphalt content. Various (42) SBS Pre-blend with asphalt binder. > 5% of residual asphalt content (forms continuous polymer matrix). Various HMA applications. (17) SBS, SB Pre-blend with asphalt. 6% of residual asphalt content. Various. (43) SBS, SB Pre-blend with asphalt. 4% by weight of asphalt content. Various low temperature applications. (33) CRM (RG-1) Post-blended in-line directly with emulsion at plant and remixed before application. 5 – 8% of total emulsion weight. Asphalt Rubber Slurry Surfacing (44) NRL (1497C) Ralumac Process – Soap pre-batching. 4% of total emulsion by weight. Various (9) EGA (Elvaloy®) Pre-blend directly with binder. 1.5 – 2.0% of residual asphalt content. Various HMA applications. (45) EVA Pre-blend with binder. 5% by weight of asphalt content. Various (31) 28
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: 2.2.7 Polymer Blends Select polymer
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 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, “
show all

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

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?