Evaluation of the Effect of WCO/SBS-Modified RAB and RAP and Stiffness Recovery Procedure on Fatigue Performance of HMA

Abstract

The use of reclaimed asphalt pavement (RAP) in asphalt mixtures is an expedient and cost-effective solution against rutting failure, but its performance against fatigue and thermal cracking is unsatisfactory and causes the pavement to deteriorate sooner than expected. Rejuvenators can improve RAP performance under various operating conditions through stiffness recovery and binder healing. In this paper, waste cooking oil (WCO) and styrene butadiene styrene (SBS) polymer were used to evaluate the rheological behavior of reclaimed asphalt binder (RAB). The modified RAB has been evaluated using chemical composition, linear amplitude sweeping (LAS), and bending beam rheometer (BBR) tests. The results of the LAS test showed that the fatigue life of RAB containing WCO was about 6 to 9 times longer than the control RAB specimen at the strain level of 2.5% and 5%. The results of the BBR test also indicated the good performance of the WCO. Thus, the WCO used in this study was expected to enhance the fatigue performance and thermal cracking of RAB. To evaluate the behavior of RAP containing RAB and additives on the fatigue response before and after self-healing, four-point bending beam test (4PBB) was employed. The results showed that besides improved fatigue life of hot-mix asphalt (HMA) produced with RAP- and RAB-containing additives, it had a longer fatigue life after self-healing. The specimen containing WCO had a better performance than the specimen to other samples.