Enhancing Flexible Pavement Performance Using LDPE-Modified Bitumen: A Comprehensive Review

This review paper investigates the use of Low-Density Polyethylene (LDPE) as a bitumen modifier in flexible pavement construction. LDPE, derived from plastic waste, offers a sustainable solution for enhancing the rheological properties of bituminous mixes. Studies show that LDPE-modified bitumen improves the softening point, penetration index, ductility, and Marshall Stability value. Additionally, it enhances resistance to water damage, rutting, and cracking, extending pavement lifespan. Various processes, including dry and wet methods, have been analyzed for their effectiveness in uniformly coating aggregates with plastic waste. Compared to conventional bitumen, LDPE-modified bitumen exhibits greater binding properties and reduced air voids. The application of LDPE as a modifier also presents significant environmental benefits by promoting plastic waste utilization. This paper further examines the combined use of LDPE and Crumb Rubber Modified Bitumen (CRMB) to mitigate the stiffness induced by LDPE, resulting in balanced elasticity and durability. The findings suggest that adopting LDPE-modified bitumen can contribute to more resilient, cost-effective, and eco-friendly road infrastructure. Future research directions include optimizing modifier percentages and assessing long-term field performance.