Aging characteristics of crumb rubber modified asphalt binder and mixture with regenerating agent

Abstract

At present, the research hotspots of recycled asphalt mainly focus on the recovery of performance, but less attention has been given to the secondary aging of recycled asphalt. Therefore, this article mainly studied the effects on the physical properties of initial aging, regeneration and secondary aging of crumb rubber modified asphalt (CRMA) and mixtures. The results show that a rubber regenerating agent (RA) can restore the performance of aged CRMA to its original level, and the optimal RA content was 8%. During the secondary aging, RA-CRMA also experience performance degradation similar to virgin CRMA due to the loss of light components and the degradation of rubber. However, on the whole, the aging index of RA-CRMA and mixture was better than that of virgin CRMA and mixture, indicating that RA improved the aging resistance of CRMA. Further, the Pearson correlations between the various aging indexes of binder and mixture were significant, and the state of secondary aging can be quickly determined through a simple binder experiment.