Low-cost chemical modification of refined used cooking oil to produce long-lasting bio-asphalt pavements

Due to its abundance, used cooking oil (UCO) can be used as a bio-rejuvenator for bitumen in roads that contain high contents of recycled asphalt pavement material to reduce costs and environmental impacts. In this study, the potential of UCO and novel epoxidized cooking oil (EPCO) was assessed to rejuvenate aged bitumen and provide long-term rejuvenation efficiency compared to plant-based commercial rejuvenators (Rej. A and Rej. B). The immediate cracking resistance of UCO and EPCO was found to be comparable to Rej. A and Rej. B whereas the long-term cracking resistance of EPCO and Rej. B was superior to that of Rej. A and UCO. The epoxide groups present in EPCO helped disperse the asphaltene clusters by creating bridges between the molecules and prevent their agglomeration, which slowed down ageing. The chemical modification of UCO enhanced its long-term rejuvenation performance, hence making EPCO a promising low-cost bio-alternative for bitumen rejuvenation.