Incorporation of Recycled Plastic Aggregates in Concrete: Effects on Compressive Strength and Environmental Footprint

The escalating global demand for sustainable construction materials has spurred interest in incorporating recycled plastic aggregates into concrete to reduce environmental impact and address plastic waste. This study investigates the effects of substituting fine aggregates with recycled polyethylene terephthalate (PET) aggregates at 0%, 10%, and 20% replacement levels on concrete's compressive strength and environmental footprint. An experimental approach, following ASTM C39 standards, evaluates compressive strength at 7 and 28 days under varying curing temperatures (20°C, 30°C), with PET aggregates treated with silica fume to enhance bonding. A simplified life cycle assessment (LCA) quantifies CO2 emissions, focusing on material production and plastic recycling processes. Expected results indicate a 5-20% reduction in compressive strength but a 10-15% decrease in CO2 emissions at 20% replacement, supporting sustainability without compromising non-structural applications. The findings highlight the potential of recycled PET aggregates to balance mechanical performance and environmental benefits, contributing to greener construction practices. Limitations, such as long-term durability, are noted, with recommendations for future research into optimized processing and structural applicability.