Investigation on the Mechanical Properties of Concrete with Different Types of Waste Plastics for Rigid Pavement

The increasing demand for sustainable construction practices has prompted the exploration of innovative materials, such as waste plastics, to enhance both environmental and mechanical performance in concrete, particularly for rigid pavements. This review investigates the mechan-ical properties of concrete incorporating four types of waste plastics—High-Density Polyethylene (HDPE), Low-Density Polyethylene (LDPE), Polyvinyl Chloride (PVC), and Polypropylene (PP). The primary focus is on how these materials affect key mechanical properties, including com-pressive strength, tensile strength, and flexural strength. The analysis reveals that HDPE and PP, at optimal levels (5-10%), can enhance flexural and crack resistance, making them suitable for non-structural applications. Conversely, LDPE and PVC tend to reduce both compressive and tensile strengths at higher substitution levels due to poor bonding with cementitious materials. Despite these challenges, incorporating waste plastics into concrete presents significant envi-ronmental and economic benefits, including plastic waste reduction and lower reliance on natural aggregates. The review also highlights the need for further research on improving plastic-cement bonding through surface treatments and hybrid mix designs. This paper contributes to the growing body of knowledge aimed at promoting the use of waste plastics in concrete, offering insights for the development of sustainable, high-performance construction materials.