Transforming plastic waste into durable concrete: a pathway to sustainable infrastructure

Abstract

Plastics are petroleum-based products with significant environmental challenges due to disposal and degradation issues. This study focuses on the use of shredded (SrPCA) and crushed plastic coarse aggregate (CPCA) as partial replacements for natural coarse aggregate (NCA) in concrete to enhance environmental sustainability. Preliminary tests showed that SrPCA (292.50 kg/m3) and CPCA (779.50 kg/m3) are lightweight aggregates with water absorption values (SrPCA: 0.08%, CPCA: 0.15%) lower than NCA (0.63%). The Densities of plastic concrete ranged between 2359 and 2470 kg/m3, classifying them as normal-weight concrete. Moreover, the compressive strengths result (33.8–45.2 N/mm2) exceeded the designed grade of 30 N/mm2, while the flexural strengths (4.44–5.97 N/mm2) aligned with recommended values of 10–15% concrete compressive strength. The concrete water absorption results (1.91–3.25%) also met quality standards (< 5%). Therefore, the study suggests that replacing 10% of NCA with plastic aggregate can produce durable and high-quality concrete, promoting environmental sustainability.