Full recycling of asphalt concrete with waste cooking oil as rejuvenator and LDPE from urban waste as binder modifier

Abstract

Some research projects have studied full recycling of reclaimed asphalt pavement (RAP). Several additives have been used to rejuvenate the RAP's aged bitumen. The authors previously studied full recycling of RAP rejuvenated with waste cooking oil (WCO). The asphalt concrete (AC) manufactured revealed good mechanical behaviour except for rutting resistance. Therefore, they decided to also include in the asphalt mixtures low density polyethylene (LDPE) from urban waste as a low-cost polymer to improve that weak point and verify if this technique was feasible and with potential as a pavement material. A laboratory plan was conceived to evaluate the mechanical performance of two rejuvenated ACs with WCO and LDPE. Stiffness, water sensitivity, resistance to rutting and fatigue cracking were evaluated. The results showed that, despite some empirical parameters usually indicated in current specifications not being met, the performance of the studied asphalt mixtures was adequate and, thus, there are good expectations about the future use of these solutions in real pavements, particularly for low and intermediate traffic levels. Based on a global analysis of the performance observed, the main conclusion was that full recycling of AC with WCO and LDPE is feasible, and the score obtained was higher than that of a conventional AC used for comparison.