The influence of regenerant with different dosages on the performance of aged SBS modified asphalt

Abstract

In asphalt pavement thermal regeneration, incorporation of regenerant can restore the properties of aged SBS modified asphalt, but the effect of regenerant on the recovery of aged asphalt and the dosage of regenerant are not clear. In this study, experiments are carried to determine the effect of regenerant on the performance of aged SBS modified asphalt and the appropriate dose. Accelerated aging test is conducted by rolling thin film oven test (RTFOT) at different times. Then, different doses of regenerant (2 %, 4 %, 6 %, 8 %, 10 %, 12 %) are added to the specimens before and after aging, and test its technical indexes such as penetration, softening point and ductility to analyze the effect of regenerant on the properties of aged asphalt. The results show that: with the increase of the amount of regenerating agent, the aging asphalt performance indexes are restored, the softening point of regenerated asphalt is reduced, and the ductility and needle penetration are increased. Based on the analysis of the relationship between the aging time of SBS modified asphalt and the amount of regenerant, interpolation fitting is carried out to obtain the formula for the best amount of regenerant, so as to determine the best regenerant dosage for aged asphalt mixes in actual engineering applications.