Research on Fatigue Performance of Fast-Melting SBS/Epoxy Resin Composite-Modified Asphalt

A high-performance composite modifier ER-SBS-T was prepared through the mixing of epoxy resin with a fast-melting styrene–butadiene–styrene modifier (SBS-T) to enhance material properties. This study evaluated the fatigue characteristics of ER-SBS-T-modified asphalt using a linear amplitude sweep test, and 70# base asphalt, SBS-modified asphalt, and SBS-T-modified asphalt were used as control groups. The fatigue life of ER-SBS-T-modified asphalt was determined according to viscoelastic continuous damage (VECD) theory. The findings indicated that as the ER-SBS-T modifier content increased, both the maximum value and the cumulative damage limit value increased, while the rate of change of decreased. At strain levels of 2.5% and 1%, the fatigue life of the modified asphalt improved with increasing ER-SBS-T content. However, at a strain level of 5%, the modified asphalt exhibited no significant trend in fatigue life across different ER-SBS-T contents. ER-SBS-T-modified asphalt with a modifier content of >10% demonstrated favorable fatigue performance suitable for practical engineering applications.