Preparation of Emulsified Type Cold-Mix Asphalt with Waterborne Epoxy Resin and Polypropylene Fiber for Pothole Repair

Abstract

This work addressed the issues of poor bonding and low forming strength of emulsified type cold-mix asphalt (CMA). The aim of this study was to improve the pothole repair effect. Accordingly, waterborne epoxy resin (WER) was adopted as an emulsifier, and samples of WER-emulsified CMA reinforced with polypropylene fiber were prepared in the laboratory. First, the mixing ratio of WER and curing agent was optimized through three indexes and storage stability tests. Second, fluorescence microscopy, dynamic shear rheology (DSR), and bending beam rheometer (BBR) tests were conducted to determine the ratio between WER and curing agent, called WERC, in emulsified asphalt binder. After that, pavement performance and bonding characteristics of asphalt mixes produced by this binder were evaluated to analyze the feasibility of using WER-emulsified type CMA in pothole repair and to determine the optimal WERC content. The results show that the best mixing ratio of E-44 and EH-05 is 1.5:1, and WER-emulsified type CMA mixes have shown improved strength, high-temperature rutting resistance, water stability, low-temperature crack resistance, and interfacial bonding characteristics. With the increase of WERC, the performance influence range gradually slows down. Considering overall performance improvement and cost, best WERC content is finally determined as 6.5%. The newly developed emulsified type CMA can be applied to the rapid repair of pavement potholes.