Performance Evolution Mechanism of Hot-Mix Epoxy Asphalt Binder and Mixture Based on Component Characteristics

In-depth exploration of the performance evolution process of hot-mix epoxy asphalt binder (HEAB) with different components can help control costs and facilitate its promotion and application in engineering. In this study, through the tensile test, viscosity test, laser scanning confocal microscope (LSCM), and Fourier transform infrared spectroscopy (FTIR), the properties of HEAB with different epoxy resin (EP) content were studied, the appropriate EP content was explored, and the curing degree was evaluated by the epoxy conversion rate. Meanwhile, the pavement performance of the HEAB mixture was studied and compared with the stone matrix asphalt (SMA) mixture. The results showed that the tensile properties of HEAB were significantly improved when the EP content reached 30% by weight, and the phase transition occurred when the EP content was 50% by weight. The appropriate content of EP in HEAB was recommended to be 40% by weight, and the mixing temperature of 160 degrees C can ensure sufficient construction allowable time range. The epoxy conversion rate gradually rose with the increase of curing time, and the early curing reaction rate was faster than the later ones. The HEAB mixture had excellent comprehensive properties, and its high-temperature stability was particularly outstanding, but the water stability and skid resistance were inferior to the SMA mixture. Hence, an upper layer of SMA and lower layer of HEAB as a composite structure of a steel bridge deck pavement are worthy of further study in the future.