Effects of Rejuvenators on Cracking Resistance of High RAP Asphalt Mixtures

Incorporating recycled asphalt mixture with reclaimed asphalt pavement (RAP) is becoming popular because of its economic and environmental benefits. However, using high RAP contents is often prone to cracking. To address the problem, recycling agents (rejuvenators) are often used to reduce the hardness of the mixture and, therefore, improve the cracking resistance. In this paper, two types of petroleum-based rejuvenators (aromatic extracts—A rejuvenator) and vegetable-based (V rejuvenator) are used at different contents (0%, 4%, 8%, and 12% by the weight of recycled bitumen). IDEAL-CT test (ASTM D8225) is used to evaluate the impact of these rejuvenators on the cracking resistance of asphalt mixtures. Laboratory test results indicated that the use of the rejuvenators improves the cracking resistance of asphalt mixtures, in which using petroleum-based rejuvenator is more effective against cracking than vegetable-based rejuvenator.