Stress-strain-strength behavior of geosynthetic reinforced rubber-sand mixtures

As a lightweight and energy-dissipating filler, rubber-sand mixture (RSM) is promising for a wide range of applications in civil engineering. However, the shear strength of RSM decreases with higher rubber content compared to that of sandy soil alone. To overcome this issue, geosynthetics are placed within RSM to increase the shear strength and overall stability of the system. This paper focuses on the stress-strain-strength behavior of geogrid-reinforced RSM, with the aim of expanding the application of RSM in geotechnical, traffic and seismic fields. Based on triaxial compression tests, the stress-strain response and strength parameters of geogrid-reinforced RSM considering the effects of reinforcement layers, rubber contents and confining pressures were analyzed. The test results indicate that the strength parameters of the geogrid-reinforced RSM are significantly improved compared to the unreinforced case, and the incremental amplitude increases with increasing the number of reinforcement layers and decreasing the confining pressure. The reinforced RSM with a 20% rubber content (by weight) might be the optimum for the use of reinforcement with geosynthetics. Additionally, a new equation is proposed to estimate the strength reinforcement effect of the composite mixtures, which could provide a reference for subsequent theoretical research and engineering applications.