INVESTIGATION ON THE MECHANICAL PROPERTIES OF LIGHTWEIGHT CONCRETE INCORPORATING RECYCLED COARSE PLASTIC AGGREGATE (RCPA)

– This study investigates the mechanical properties of lightweight concrete incorporating Recycled Coarse Plastic Aggregate (RCPA) as a partial replacement for natural coarse aggregates. The research focuses on addressing environmental issues caused by plastic waste while exploring sustainable construction materials. Concrete mixes were prepared by replacing natural aggregates with RCPA at different proportions (10%, 20%, 30%, and 40%). The performance of concrete was evaluated through tests such as compressive strength, split tensile strength, flexural strength, workability, and density. Additionally, the effect of elevated temperatures (600°C and 800°C) on concrete properties and spalling behavior was studied. Results indicate that the inclusion of RCPA reduces the unit weight and density of concrete, making it suitable for lightweight applications. Mechanical properties initially improve with increasing RCPA content, reaching optimum performance at around 30% replacement, after which strength decreases due to poor bonding between plastic aggregates and cement paste. High temperatures further influence the strength and durability characteristics. The study concludes that RCPA can be effectively used as a sustainable alternative material in concrete for non-structural and lightweight applications, contributing to waste management and resource conservation.