Evaluating the Effect of Polymer Rejuvenators on the Recycled Asphalt Mixture Performance

Many researchers have shown that using rejuvenators and polymer-modified bitumen can improve the performance of recycled asphalt mixtures against cracking, fatigue, and rutting. Nevertheless, limited research has been performed on modified rejuvenators with polymer, and there are many obscurities on the performance of these rejuvenators on the behavior of the recycled asphalt mixture. Therefore, in this research, the performance of 25%, 50%, and 75% RAP mixtures containing polymer rejuvenator (i.e., nanopoly, Tiss, and crumb rubber modified waste cooking oil (MWCO)) and vacuum bottom have been studied, and the results were compared together. For this purpose, after obtaining the optimal percentage of each rejuvenator and performing the mix design formula tests, the dynamic creep test, moisture sensitivity test, and semi-circular bending test were conducted. The results show that the modification of rejuvenators with polymer improves the rutting resistance of mixtures. Also, the mixtures containing nanopoly and Tiss, despite the weaker initial cracking resistance, have a better performance against the growth of the crack. Furthermore, the mixtures containing tiss and nanopoly showed a good performance against moisture sensitivity. The mixtures containing MWCO did not perform well against cracking and moisture sensitivity.