Laboratory Performance Evaluation of a Waterborne Epoxy-Modified Asphalt Mixture with Styrene-Butadiene Rubber for Cold Patching Applications

Abstract

Cold mix asphalt (CMA) is commonly used for repairing asphalt pavement potholes. Ordinary CMA has the problems of poor construction workability and low initial strength in low-temperature environments. To improve pothole repair using CMA in low-temperature environments, a solvent-type cold asphalt liquid (CAL) has been developed and modified by a waterborne epoxy and styrene-butadiene rubber (WER+SBR). First, a low-temperature curing test, compatibility test of WER and SBR latex, and 60°C viscosity test of CAL were conducted and evaluated, and then the type of WER was selected. Second, an orthogonal test with four factors of diluent, WER, SBR, and tackifier was designed to analyze the effects of each factor on 60°C viscosity, adhesion grade, storage stability, and distillation residue of WER+SBR type CAL, and the best raw material ratio was determined. Finally, low-temperature construction workability and road performance of WER+SBR type CMA were evaluated. The results show that EP-20 can be used as the optimal WER for low-temperature type CAL, and the preferable composition of WER+SBR type CAL is SK90# asphalt (100): diluent (26): tackifier (5): WER (4): SBR (2). Compared with ordinary CMA, WER+SBR type CMA is excellent in initial strength, forming strength, high-temperature stability, low-temperature crack resistance, water stability, and low-temperature construction workability. WER+SBR type CMA can be applied to pothole repair in low-temperature environments, which is an important development in improving the repair of asphalt pavement potholes.