Innovative Utilization of HDPE-Plastic Aggregates in Concrete: Fresh and Mechanical Properties

This study addresses the twin issues of managing plastic waste and the demand for sustainable building materials by examining the creative use of high-density polyethylene (HDPE) plastic as an aggregate in concrete. HDPE plastic was melted at approximately 390°C and mixed with sand in ratios of 1:1 and 1:2 to create HDPE-plastic aggregates. These aggregates were then incorporated into concrete with water–cement (w/c) ratios of 0.40, 0.45, 0.50, and 0.55. Comprehensive tests were conducted to evaluate the fresh and mechanical properties of the resultant concrete, including workability, compressive strength, tensile strength, and flexural strength. The experimental results indicated that the HDPE-plastic aggregate concrete exhibited satisfactory performance, meeting industry standards for structural applications. Specifically, the mechanical properties showed promising results, with compressive, tensile, and flexural strengths comparable to traditional concrete mixes. This research highlights the environmental benefits of this novel approach, demonstrating that utilizing waste HDPE plastic in concrete not only diverts significant amounts of plastic from landfills and oceans but also reduces the demand for natural aggregates. Consequently, this approach conserves natural resources and decreases the environmental footprint of concrete production, contributing to sustainable construction materials and offering a viable solution for managing plastic waste.