Investigation on the survival and activating behavior of rejuvenator-loaded fibers in asphalt pavement

Abstract

Embedding encapsulated rejuvenator is a promising approach to enhance the self-healing performance of asphalt pavement. The effectiveness of this approach critically relies on the survival and activating behavior of encapsulated rejuvenator during the construction and service period. In this paper, the survival and activating behavior of rejuvenator-loaded fibers (RL-fibers) were simulated and analyzed through a series of laboratory tests. The mixing test and X-ray computed tomography (CT) scanning test were employed to investigate the survival behavior of RL-fibers by analyzing the morphological changes of RL-fibers before and after the construction process. Furthermore, stress-activating and microwave-activating experiments were designed to investigate the responses of RL-fibers to crack and microwave irradiation. Test results showed that despite experiencing significant deformation and fragmentation during construction, the RL-fibers maintained a 91 % survival rate, suggesting minimal rejuvenator leakage and negligible adverse effects on the performance of asphalt pavement. The RL-fibers were uniformly distributed radially within the compacted asphalt mixture specimens, while longitudinal aggregation was observed near the mid-depth region. The RL-fibers had sufficient interfacial adhesion strength with the asphalt matrix, enabling synchronous fracture under mechanical loading. After the fracture of RL-fibers, the encapsulated rejuvenator was quickly released and started to spread along the cracks. Microwave irradiation was shown to effectively trigger rejuvenator release, with the activating rate of RL-fibers increasing progressively with microwave exposure duration: 9.7 % (40 s), 17.5 % (60 s), 35.3 % (80 s) and 49.2 % (100 s). In conclusion, these findings provide valuable insights into the survival and activating behavior of RL-fibers in asphalt pavement, contributing to the ongoing research efforts in optimizing pavement durability while reducing life-cycle maintenance costs.