Mechanical Performance of Warm Mix Asphalt Incorporating Polyolefin Waste as Aggregate

Abstract

[Abstract]: The widespread use of plastics in modern society, coupled with the challenges of recycling certain types, has driven the exploration of their application in asphalt mixtures to promote circular economy principles and mitigate environmental impact. This laboratory study explores the feasibility of using polyolefin waste as a partial aggregate replacement in warm mix asphalt (WMA) using the dry process without additional treatment. The research began by determining the optimum bitumen content through a mixture design based on the moisture damage resistance test. This same test was then used to identify the optimum polyolefin waste content from seven different WMA mixtures, introducing the coarse-sized polymer as an aggregate substitute, at mass-based replacement rates (0.5%, 1.0%, 1.5%, 5.0% and 10.0%) with volume control, and employing two distinct incorporation methods. Subsequently, the control and polyolefin-modified mixtures were evaluated regarding volumetric and mechanical properties, including abrasion resistance, stiffness, thermal susceptibility, resistance to permanent deformation and fatigue life. The findings demonstrate that incorporating polyolefin waste at a substitution level of 0.5% enhances both abrasion and moisture damage resistance, effectively repurposing a challenging waste material. However, despite these benefits, it also presents some limitations in permanent deformation resistance compared to the control mixture.