Performance of plastic waste for soil improvement

Abstract

Recycling plastic waste from water bottles has become one of the main challenges worldwide. The aim of this study is to recycle empty plastic water bottles as reinforcing material for the improvement of sandy soil. The laboratory tests were performed on both natural and reinforced sands with different plastic waste percentages: 0, 0.5, 0.75 and 1.0 of the dry weight of sand at relative density states of 30% and 60%. Direct shear box and the California Bearing Ratio, CBR tests were performed to determine the effect of the plastic waste on the shear strength and the penetration resistance of the reinforced sand. Test results indicated that plastic waste reinforcement contributed to the improvement of the shear strength and the CBR number of the reinforced sand. Higher shear strength and higher penetration resistance were obtained with plastic waste reinforcement. The optimum percentage of plastic waste required for enhancing the shear strength and the CBR number was found to be 0.75%. With the optimum percentage of plastic waste, the improvement in the shear strength and the penetration resistance of the reinforced sand increased to at least 9% compared to natural soil at relative density states of 30% and 60%.