Mechanism and Performance Investigation of SBS/Sulfur Composite Modified Asphalt

To improve the performance of asphalt, the modified asphalt was prepared by adding styrene-butadiene-styrene block copolymer (SBS) and sulfur powders into the base asphalt. The storage behavior of asphalts was tested to optimize the quality of adding SBS and sulfur. The storage stability and viscoelastic properties of modified asphalts were also studied. The results showed that under the proportioning final addition of SBS and sulfur, the storage stability, the high and low-temperature performance of asphalt was greatly improved, making it possible to meet the stability requirements for high-temperature storage of asphalt. Additionally, only a small amount of acidic sulfur-containing gas such as H2S escaped during the modification process. The microscopic observation showed that the “sea-islands” form of SBS-modified asphalt was changed to a uniform and continuous dual-phase structure after sulfur addition. Finally, it was proposed that sulfur induced the chemical reaction between SBS and asphalt to form a stable network structure, which was the intrinsic mechanism to improve the performance of asphalt.