Effect of different rejuvenation methods on the fatigue behavior of aged SBS modified asphalt

Reclaimed bituminous mixture can be used in new pavement after rejuvenation. Common rejuvenation method and reactive rejuvenation method can be used to restore the properties of aged SBS modified asphalt(ASMB). This work focused on the recovery effect of fatigue resistance for ASMB by different rejuvenation methods. The effect of common and reactive rejuvenation on the fatigue behavior of ASMB was investigated by multi-stress creep and recovery test, linear amplitude sweep test and fatigue-healing-fatigue test. The results show that, as compared with common rejuvenation method, reactive rejuvenation method is more conducive to restoring the creep recovery rate and the non-recovered creep compliance of ASMB. Linear amplitude sweep test indicates that reactive rejuvenated ASMB shows the good fatigue stress cracking resistance, the fatigue life of which at 2.5% and 5.0% strain levels is increased by 30% and 71% as compared with that of common rejuvenated binder. Meanwhile, the self-healing index of reactive rejuvenated ASMB is also enhanced by 28.7%, which indicates its better self-healing potential and fatigue damage resistance. Furthermore, the fatigue life of SMB is reduced by 77.7% after aging, while that of ASMB is extended by 93.5% after common rejuvenation, and the fatigue life of reactive rejuvenated ASMB is almost twice than that of common rejuvenated binder. It means that reducing the adverse effects of aged asphalt and reconstructing the broken SBS cross-linking structure during rejuvenation process of ASMB are all crucial for restoring its fatigue resistance.