Laboratory determination of strength properties of frozen rubber–sand mixtures

The objective of this study was to investigate the strength characteristics of frozen rubber–sand mixtures. Uniaxial compressive strength, direct-tensile strength and direct-shear tests were conducted on rubber–sand mixtures at various rubber contents (0, 10, 15, 20, and 30%) and low temperatures. The results showed that the strength characteristics of rubber–sand mixtures were influenced by temperature and rubber content. It was found that the strength of frozen sand and rubber–sand mixtures was significantly greater than that of unfrozen sand and rubber–sand mixtures. The increase in strength continued with a decrease in subfreezing temperature. The addition of rubber to sand decreased the strength, namely, the higher the rubber content in the mix, the lower the strength. Based on compaction characteristics and the formulation of minimum void ratio the optimum rubber-mixing ratio was found to be around 15%. The strength test data suggests that a low rubber-mixing ratio and subfreezing temperature give high strength, while the addition of rubber to sand provides an opportunity to control failure deformation characteristics and earth pressure.