Evaluation on the mechanical performance of recycled asphalt mixtures incorporated with high percentage of RAP and self-developed rejuvenators

Abstract

Because of the scarcity of irreplaceable natural resources and environmental pollution of demolished asphalt pavement, circular utilization of Reclaimed Asphalt Pavement (RAP) to prepare recycled asphalt pavement mixtures was promoted. To restore properties of the aged bituminous binder in RAP, rejuvenators designed with diverse viscosity levels and their rejuvenating effects have been investigated in previous studies. However, the influence of self-developed rejuvenators on the mechanical performance of high percent RAP recycled asphalt mixtures is not clear. In this study, two self-developed rejuvenators with different viscosities were incorporated in recycled asphalt mixtures and their influences on mechanical properties were assessed comprehensively. The wheel tracking test and three-point bending test were conducted to assess the rutting resistance and cracking behavior of recycled asphalt mixtures, respectively. The Hamburg Wheel Tracking (HWT) test and Simple Performance Test (SPT) were applied to evaluate the moisture durability and dynamic response of recycled asphalt mixtures. Fatigue resistance of recycled asphalt mixtures was assessed by using two-point bending test. The experimental results indicated that using the self-developed rejuvenators improved the cracking behavior and fatigue life of recycled asphalt mixtures. Incorporation of RAP improved the rutting resistance and dynamic modulus of recycled asphalt mixtures. Even though adding rejuvenators caused the recycled asphalt mixtures prone to permanent deformation, their moisture durability was still better than that of the new asphalt mixture. It thus suggests that the mechanical behavior of recycled asphalt mixtures can be improved by using self-developed rejuvenators.