Research on Engineering Performance of Paving Mixes with Multi-component SBS Modifier under Dry Modification

Abstract

Abstract Dry modification of modified asphalt mixtures prepared by mixing the modifier with the aggregate and asphalt binder is a simple and environmentally friendly process. It can avoid the segregation of modified asphalt used for paving mixes under wet modification mode. The difficulty of rapid swelling makes it difficult for the styrene-butadiene-styrene block copolymer (SBS) modifier to achieve dry modification. This research attempted to prepare a multi-component SBS-based (SBSM) modifier for dry modification by blending SBS with assisting ingredients through a twin-screw extruder. The conventional properties, rheological properties, and thermal storage stability of SBSM-modified asphalt were evaluated. Additionally, the road performance of SBSM-modified asphalt mixtures prepared by both wet modification and dry modification was characterized. The results show that SBSM-modified asphalt obtains excellent high-temperature and low-temperature properties as well as thermal storage stability. Satisfactory performance in terms of resistance to high-temperature rutting, low-temperature cracking, and water damage is obtained when the SBSM modifier was applied in modified asphalt mixtures under wet modification. Compared with the SBSM-modified asphalt mixture under wet modification, the road performance of the SBSM-modified asphalt mixture under dry modification is slightly inferior, especially the water stability, but satisfies the engineering requirements. The findings demonstrate the feasibility of the dry modification of the SBSM modifier for paving mixtures and promote the development of SBS-based modifiers for dry modification.