Enhancing asphalt mixture performance through waste plastic modification: a comprehensive analysis of optimal compositions and volumetric properties

This study explores the innovative use of waste plastic, including polyethylene terephthalate (PET), high-density polyethylene (HDPE), and polyvinyl chloride (PVC), as additives in VG30-grade bitumen for road construction. The research focuses on precise proportions of plastics to achieve optimal performance, utilizing a meticulous methodology involving laboratory tests, particularly the Marshall Stability (MS) test. The investigation reveals that a 3.0 % waste plastic content, specifically with 100% PET, and 5.5 % bitumen content results in the highest MS, demonstrating a 73.07 % improvement over the control mix. Additionally, the study examines the nuanced relationships between waste plastic incorporation, bitumen content, and volumetric properties such as air voids, bitumen volume, voids in mineral aggregate, and asphalt-filled voids. The findings emphasize the importance of carefully balancing these factors to achieve the desired properties in the modified asphalt mix. Notably, the 5.5 % bitumen composition consistently demonstrates superior performance across various parameters. The research contributes valuable insights into the potential enhancements brought about by waste plastic additives, particularly 100 % PET, in asphalt mixtures. The identified optimal compositions enable the development of sustainable and high-performance asphalt materials for road construction, meeting the demand for eco-friendly solutions in infrastructure development.