Low-temperature Performance of Seal Coat

This study presents the evaluation of low-temperature performance of seal coat in terms of friction performance and aggregate-loss performance. In addition, factors affecting the sealcoat performance at low temperature were also investigated. Ten seal coats on United States (U.S.) highways and State Roads in Indiana were selected and the friction tests were conducted in spring and fall for approximately 4 to 6 years after the construction. Three emulsions and seven aggregates consisting of CRS-2 P, RS-2 P, and AE-90 S for emulsions and trap rock, sandstone, blast furnace slag, steel slag, limestone, dolomite, and crushed gravel were used for the Vialit test for aggregate-loss performance, the zeta potential test for the effect of electrostatic property, and the bending beam rheometer (BBR) test and thermomechanical analysis (TMA) test for the effect of mechanical and thermo-properties of emulsion. Friction numbers on ten seal coats constructed in Indiana from 2007 and 2013 showed that the winter season has a more significant impact on the friction reduction than the impact the summer season has. The Vialit test result showed that an increase in aggregate loss occurred as the temperature decreased, regardless of aggregate-emulsion combinations. The low-temperature aggregate loss is more sensitive to the emulsion type than to the aggregate type. The higher zeta potential of emulsion resulted in better aggregate-loss performance at low temperatures below-17°C. However, the effect of electrostatic interaction between the aggregate and emulsion particles on aggregate-loss performance was found to be statistically insignificant. The emulsion with a softer binder (lower stiffness) performed better than the emulsion containing a stiffer binder in terms of aggregate-loss performance at low temperatures. Last, the coefficients of thermal expansion of emulsion residues were not an influence on factors affecting the low-temperature aggregate-loss performance using the three emulsion types.

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  • English

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  • Accession Number: 01611058
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Sep 2 2016 11:11AM