Modified Waterborne Epoxy as a Cold Pavement Binder: Preparation and Long-Term Working Properties

The purpose is to enhance the working properties of waterborne epoxy resin and improve the quality of cold pavement binder usage. In this study, a modified waterborne polyurethane/epoxy composite was prepared. The influence of the type and content of the polyurethane on the working properties of a composite was studied. The optimum composition and ratio of the composite were determined. The properties of the waterborne epoxy at different working conditions and treatment times were analyzed. The long-term evolution law of property of waterborne epoxy was clarified. The correlation between different working properties of waterborne epoxy was studied. The results show polyurethane can improve the working properties of waterborne epoxy resin. Considering the tensile, bending, and bonding properties, the suitable type of polyurethane is toluene diisocyanate-polybutylene adipate (TDI-PBA), and the suitable content is 15%–20%. With the increase of hydrothermal aging time, the strength of waterborne epoxy resin increases 5%–10%, the flexibility reduces 6%–12%, and the bonding property decreases 70%–75%. After polyurethane modification, the property stability of waterborne epoxy resin is enhanced. The retention rate of the bonding property increases significantly, at approximately 120%–150%.