Development of low-cost plastic-modified concrete pavers for applications in Zambia

Abstract

This study investigated the use of shredded Low-Density Polyethylene (LDPE) and High-Density Polyethylene (HDPE) plastic waste as a partial replacement for fine aggregates in concrete pavers, addressing both environmental concerns about plastic pollution and the need for affordable construction materials. The study developed M30-grade concrete mixes with plastic replacements of 10%, 20%, and 30% by volume, testing their workability, compressive strength, and aggregate properties using standardized protocols. The results revealed that although increasing the plastic content reduced compressive strength, pavers incorporating 10% to 20% fine plastic aggregates still achieved an average compressive strength of 20 MPa and a minimum of 17 MPa, making them suitable for equipment parking or light-traffic applications. The incorporation of plastic also decreased workability and material density while improving water resistance. This study demonstrates the potential of utilizing waste plastics in concrete paver production to promote environmental sustainability and reduce construction costs. A 10–20% plastic content is recommended for pedestrian pathways, with standardized preparation methods for plastic waste and field trials in tropical climates essential to ensure consistency and assess long-term performance.