Effect of external factors on the performance of waterborne epoxy resin modified emulsified asphalt as interface bonding material for potholes

To improve the interface bonding performance between new and old pavement materials in potholes, this study employed waterborne epoxy resin modified emulsified asphalt (WEREA) as the interface bonding material. Initially, tests were conducted to evaluate the properties of emulsified asphalt binder modified with different contents of waterborne epoxy resin (WER), and three contents with superior performance were selected. These selected WEREA binders were applied as interface bonding materials for potholes, and the external factors of coating mass, temperature, dust contamination, water immersion, freeze-thaw cycles, and repeated traffic loads on the interface performance of WEREA-reinforced asphalt specimens were examined. The results were also compared with those of unmodified emulsified asphalt. The results indicate that the incorporation of WER improves the high temperature performance, tensile strength, and adhesion strength of emulsified asphalt, and accelerates its curing process, but slightly compromises its low temperature performance and elongation at break. Emulsified asphalt modified with 15%, 20%, and 25% WER was selected as the interface bonding material for potholes, and the optimal coating mass was determined to be 0.7 kg/m2. Furthermore, compared with conventional emulsified asphalt, WEREA exhibited enhanced interfacial bonding performance under adverse conditions, with the improvement becoming increasingly pronounced as the WER content increased.