Effect of polyvinyl chloride waste granules on the uniaxial compressive strength of clayey soils

This study aims to investigate the impact of polyvinyl chloride (PVC) waste granules from discarded pipes on the uniaxial compressive strength (UCS) of two clayey soils using various mixing ratios. Soil 1 and Soil 2 were sourced from El- Idrissia and central Djelfa, Algeria, respectively.PVC granules (0%, 0.5%, 1%, 2%, and 10%) were mixed with dry clay soil, and UCS tests showed that PVC granules enhanced soil strength. Adding 0.5% and 5% PVC to Soil 1 increased UCS by 6.84% and 46.58%, respectively, making these values 1.5 times higher than unreinforced soil. For Soil 2, UCS increased by 14.62% and 88.46% with the same PVC proportions, over twice the strength of soil without PVC. PVC granules improved the compressive strength and resistance of clayey soils, enhanced their ductility noticeably, and prevented crack propagation and soil deformation. Microscopic analysis revealed significant interactions between PVC surfaces and clay particles, positively impacting soil behavior. Stabilizing clay soil with PVC waste produced isotropic materials with fewer desiccation cracks, improving compressive strength. This study offers practical applications for reinforcing weak soils in infrastructure, foundations, and road materials, providing significant economic and environmental benefits.