Performance and Feasibility of Plastic Waste-Modified Asphalt Mixes in Highway Infrastructure: A Review

The incorporation of plastic waste in asphalt mixtures has emerged as a sustainable approach to enhance road durability while addressing environmental concerns. This review synthesizes studies examining the effects of various polymers, such as high-density polyethylene (HDPE) and low-density polyethylene (LDPE), in modified asphalt. Findings indicate that polymer-modified asphalt mixtures exhibit improved resistance to rutting, cracking, and moisture damage. For instance, Awwad and Shbeeb (2007) and Bindu et al. (2010) showed that adding HDPE and LDPE enhances the strength and stability of asphalt mixes. Several studies, including Fernandez et al. (2008), highlight the role of oil-based additives as compatibilizers to optimize polymer dispersion and rheological properties. Marshall stability and tensile strength tests confirm the increased performance of these modified mixtures under varying environmental conditions. Overall, the inclusion of 5-15% plastic waste significantly improves asphalt's mechanical properties, lifespan, and environmental compatibility. This review concludes that polymer-modified asphalt offers a viable solution for sustainable road infrastructure, with optimal outcomes observed at specific temperature and additive dosage levels.