Performance Assessment of Reclaimed Asphalt Pavement Mixtures Rejuvenated with Waste Cooking Oil

Abstract

The increasing demand for sustainable and cost-effective pavement construction materials has accelerated the exploration of alternative pavement engineering solutions. Reclaimed Asphalt Pavement (RAP), produced from milled asphalt layers containing aged bitumen and aggregates, has emerged as an effective approach for conserving natural resources and minimizing environmental impacts associated with road construction. However, the aged binder presents in RAP undergoes oxidation and hardening over time, resulting in increased stiffness and brittleness, which adversely affect the performance of recycled asphalt mixtures when reused without treatment. This study evaluates the rejuvenation of aged Reclaimed Asphalt Pavement (RAP) binder using Waste cooking Oil (WCO) as a sustainable rejuvenator. An experimental program comprising binder characterization and mixer performance tests, including Marshall Stability, Indirect Tensile Strength, Tensile Strength Ratio, Wheel Tracking and Semi-circular Bending tests were conducted to determine the optimum WCO dosage. Results showed that 25% WCO by weight of RAP binder effectively restored penetration and viscosity properties comparable to virgin VG-40 bitumen. Rejuvenated RAP mixtures exhibited improved workability, rutting and cracking resistance, while 2% hydrated lime enhances tensile strength and moisture resistance characteristics. The findings demonstrate that the combined utilization of RAP and WCO provides a sustainable, economical, and environment friendly solution for pavement construction. The proposed rejuvenation technique enhances the durability and performance of recycled asphalt mixtures while reducing material consumption, energy demand, and environmental footprint in roadway infrastructure development