Study on the microstructure and properties of hot-mix epoxy asphalt

Abstract

Epoxy asphalt concrete (EAC) has excellent high-temperature stability and fatigue durability and is extensively used as steel deck pavement. The spatial microstructure of one type of hot-mix epoxy asphalt was investigated using fluorescence microscopy and scanning electron microscopy (SEM). The properties of the epoxy asphalt (EA) and EAC with different epoxy resin to epoxy asphalt binder (epoxy to binder, ETB) ratios were investigated using tensile tests, rutting tests, Marshall tests and three-point beam bending tests. The curing process of the EAC at different temperatures was evaluated. The experimental results indicated that the asphalt phase transferred to the epoxy phase at a 37 wt% ETB ratio. When the ETB ratio was above 37 wt%, the epoxy resin began to form a continuous phase with a spatial crosslinked structure, and the asphalt acted as the disperse phase, filling the crosslinked structure of the epoxy resin and providing toughening and anticorrosion effects. The mechanical test results showed that the ETB ratio had a significant influence on the performance of the EA and EAC. The increasing strength curves during the curing process showed that the strength of the EAC increased faster at higher temperatures and during the first half of the curing process.