Experimental study of epoxy asphalt binder and porous epoxy asphalt concrete

Epoxy asphalt binder offers a promising solution for road material due to its low environmental impact and potential to reduce carbon emissions. In this paper, hot-mix epoxy asphalt binder (HEAB) and warm-mix epoxy asphalt binder (WEAB) were prepared firstly. The curing conditions of the binders were determined through viscosity and tensile tests, and their low-temperature properties were evaluated through bend creep stiffness tests. Furthermore, hot-mix porous epoxy asphalt concrete (HPEC) was designed with target void ratios ranging from 16% to 24%. Control groups included warm-mix porous epoxy asphalt concrete (WPEC) and high-viscosity modified porous asphalt concrete (HPAC) with a 20% target void ratio. The road performance of these various porous asphalt concrete was evaluated through multiple tests, including wheel tracking, low-temperature beam bending, dynamic modulus, four-point bending fatigue, freeze-thaw splitting, and Cantabro loss tests. The results indicate that HEAB follows a two-stage curing method of "160 °C, 2 h + 60 °C, 4 d", while WEAB adopts a one-stage curing method of "120 °C, 5 h", both of which demonstrate favorable properties. Moreover, HEAB exhibits better low-temperature properties compared to WEAB. The study also found that increasing the void ratio can reduce the high-temperature performance, freeze-thaw resistance, hydrothermal resistance, and dynamic modulus of HPEC. The low-temperature performance of HPEC reaches an inflection point at a target void ratio of 20%. Under the same target void ratio, HPEC exhibits the best high-temperature performance, dynamic modulus, fatigue resistance, freeze-thaw resistance, and hydrothermal resistance, followed by WPEC and HPAC. However, the low-temperature performance of both the HPEC and WPEC is lower than that of the HPAC. Overall, the use of epoxy asphalt binder in the preparation of porous asphalt concretes shows great potential for enhancing road performance.