Surface Treatment Optimization of Thermal-Resistant Aggregate for Pavement

Abstract

To render thermal-resistant aggregates more suitable in asphalt mixtures, the optimal process for treating three typical thermal-resistant aggregates—shale ceramsite (SC), porous volcanic rock (PVR), and refractory gravel (RG)—with two organic treatment agents—silicone resin (SR) and silicone–acrylic (SA) emulsion—was determined according to the basic properties test. Further, the best agent for different aggregates was recommended according to a scanning electron microscopy and road performance. The results indicate that the optimum concentrations of SR for SC, PVR, and RG are 25%, 25%, and 15%, respectively, and the curing temperature is 160°C. In contrast, the optimum concentrations of the SA emulsion are 35%, 25%, and 15%, respectively, the additive content is 3%, and the film formation temperature is 30°C. Furthermore, the surface package effect of SR-treated aggregates is better than that of the SA-treated aggregates. Both agents can improve the road performance of thermal-resistant aggregates. Finally, using SR to treat SCs and PVRs, and to treat RGs with a SA emulsion, is recommended.