Abstract: Warm mix asphalt mixture is a road material with broad application prospects, but its insufficient low-temperature crack resistance and water stability performance limit its engineering applications. This study successfully prepared porous Mg-Al-based layered double hydrotalcites (SDS-LDHs) intercalated with sodium dodecyl sulfate (SDS) through hydrothermal synthesis and calcination restoration methods. The microstructure and water release behavior of SDS-LDHs were investigated using scanning electron microscopy (SEM) and thermogravimetric-differential scanning calorimetry (TG-DSC), and the optimal SDS-LDHs content was determined by Brookfield viscosity tests. The pavement performance of warm mix agent was further evaluated through high-temperature rut, semi-circular bending, and Hamburg rut tests. The results show that SDS-LDHs exhibit a three-dimensional porous structure with a water content of 13.64%. When incorporated SDS-LDHs into asphalt, they rapidly and uniformly release water, effectively reducing asphalt viscosity. With 2% (by asphalt mass) SDS-LDHs, the mix temperature and compaction temperature of warm mix asphalt mixture decrease by 20 and 15 ℃ respectively compared to hot mix asphalt mixture. Moreover, SDS-LDHs enhance the high-temperature performance stability and water stability of mixture by 36.0% and 51.4% respectively compared to hot mix asphalt mixture, while only reducing low-temperature fracture energy by 3.1%. SDS-LDHs not only absorb light components of asphalt but also chemically interact with siloxane groups on aggregate surfaces, thereby improving asphalt-aggregate adhesion and ultimately enhancing the pavement performance of warm mix asphalt mixture.

Key words: porous hydrotalcite, warm mix agent, asphalt mixture, organic modification, pavement performance