The direct shear strength of sand-tyre shred mixtures

Waste tyres are currently being stockpiled in large quantities around the world causing adverse environmental impact. Significant research is currently underway to investigate possible options for the reuse of waste tyre, particularly in civil engineering applications. One such option is to utilise waste tyre (in the form of tyre shreds) and sand mixture as a lightweight fill material in infrastructure constructions. Utilising waste tyre in civil engineering projects has multiple benefits, including effective recycling of the waste tyre easing the strain on natural fills, reducing material costs and enhancing the geotechnical properties of the soil. Under-standing the shear and volume change behaviours of waste tyre and sand mixture is critical before recommending the mixture as an appropriate lightweight-reinforcing structural fill. Therefore, the objective of this study is to investigate the effect of tyre shreds on the shear behaviours of sand using large scale direct shear apparatus. The effect of tyre shreds on the vertical strain (volume change) behaviour of sand has also been investigated. It has been observed that tyre shreds have significant influence on the shear and vertical strain behaviours of sand. The findings of this study demonstrate that overall improvements in the soil characteristics, such as en-hanced shear strength, can be achieved by the addition of tyre shreds