Study on the water stability and safety mechanism of warm-mix recycled SBS- modified asphalt mixture

The warm-mix recycled asphalt mixture (abbreviated as RAM), which integrates warm-mix technique with recycling technology, offers significant energy savings and promotes the effective use of waste materials, delivering both environmental and economic benefits. However, there has been limited research exploring the water stability and safety mechanisms of warm-mix recycled SBS-modified asphalt (abbreviated as SBSMA) mixture. For this reason, this study selected Evotherm surface-active additive to investigate its impact on the properties of recycled asphalt binder and its corresponding mixture, compared and analyzed the differences between road properties of hot-mix RAM and warm-mix RAM, focusing on the warm-mix RAM water stability and the safety mechanism of warm-mix additive. The results revealed that while Evotherm did not significantly alter the penetration, softening point, or ductility of recycled SBSMA, it enhanced the surface energy and aggregate adhesion. In comparison to hot-mix RAM, warm-mix RAM demonstrated superior fatigue resistance, better low-temperature cracking resistance, and enhanced water stability. The warm-mix RAM water stability was significantly affected by factors such as mixing temperature, the incorporation method of warm-mix additive, and its dosage. The above research provided valuable insights for the efficient and safe application of warm-mix recycled asphalt technology.