Using Shredded Waste Plastics as Replacement for Coarse Aggregate

The paper examines the feasibility of using shredded waste plastics as a partial replacement for natural coarse aggregate in concrete, aiming to address plastic waste management challenges in India Standard mix designs for 25MPa concrete are utilized, with one control mix and four experimental mixes containing varying percentages of shredded waste plastics (0%, 25%, 30%, and 35%) by weight of coarse aggregate. A total of 72 cubes are produced for testing. The experimental results reveal that as the proportion of shredded waste plastics in concrete increases, there is a decrease in both tensile strength. However, at 28 days, the target strength of 25MPa is achieved by both the control concrete mix and the mix containing 25% shredded waste plastics. Previous studies referenced in the paper explore different approaches to incorporating waste plastics in concrete production, including substituting fine aggregate with PET processed particles, replacing natural fine aggregate with waste plastic, and producing lightweight aggregates from PET bottles. These studies report varying effects on concrete properties, including workability, density, and mechanical strength, with different percentages of waste plastic replacements.