Investigation of fatigue performance of asphalt binders containing SBS and CR through TS and LAS tests

Abstract

The styrene–butadiene-styrene (SBS) and crumb rubber (CR) composite modified asphalt exhibits excellent prospects for engineering applications; nevertheless, few studies have focused on its fatigue performance. This study evaluated the fatigue performance of SBS and CR composite modified asphalt by the Linear Amplitude Sweep (LAS) and Time Sweep (TS) tests. Furthermore, four failure criterions, that is 50 % modulus reduction, S × N peak, where S is the stiffness ratio and N is the number of loading cycles, dissipated energy ratio (DER) and the area of hysteresis curve, were utilized to describe the fatigue performance of the asphalt binder in TS test. The results showed that the base asphalt fatigue life was significantly increased with the addition of CR or SBS. Regardless of the test method, the fatigue performance of the SBS and CR composite modified asphalt binder was significantly better than that of the other three types of asphalt binder. The SBS + 15 % CR composite modified asphalt is recommended as the best binder. There was a good correlation between the two experimental methods, and an extremely strong correlation (R2 = 0.986) was found between DER and S × N peak criterions. The area of the hysteresis curve as an indicator of energy dissipation to define the fatigue damage of asphalt binders may be a promising indicator.