Program for Sustainable Pavement Engineering and Research

About the research

Limited local availability often constrains the growing demand for high-quality aggregate materials in road construction. To address this challenge, recycled waste materials, including plastics, are being explored as sustainable alternatives. This study investigates the feasibility of incorporating recycled plastics into asphalt and concrete pavements to enhance sustainability and reduce landfill waste. Comprehensive laboratory testing was conducted to evaluate the performance of plastic-modified asphalt and concrete. Asphalt mixtures were produced using the wet process method and assessed for binder performance, cracking resistance, and moisture susceptibility. Concrete mixtures incorporating recycled plastics as aggregate replacements were analyzed for workability, mechanical strength, and durability. The test results on plastic-modified asphalt indicated a reduced cracking resistance of the mixture when Post-Consumer Recycled (PCR) plastic was added to the binder using a wet process as compared to the same mixture with the same binder without plastic. In concrete mixtures, incorporating plastic materials either maintained statistically similar mechanical and durability properties (when used as plastic sand) or enhanced them (when used as plastic fiber). Integrating recycled plastics into road construction offers a sustainable solution for reducing landfill waste, lowering carbon emissions and promoting a circular economy.