Experimental investigation of the mechanical behaviour of sand-rubber-gravel mixtures

This study explores the mechanical behavior and properties of sand-rubber-gravel (SRG) mixtures under various testing conditions. Through an extensive series of experimental tests—including direct shear, oedometer, saturated and unsaturated triaxial, and cyclic triaxial tests—the effects of rubber and gravel additions on sandy soil are systematically evaluated. The findings reveal that the appropriate content of rubber and gravel is crucial for ensuring the improvement of soil properties. An insufficient addition may not significantly enhance the soil’s properties, while an excessive amount can lead to a deterioration of its mechanical characteristics. With the optimal mixture ratio, test results show significant improvements in shear strength and deformation resistance of the SRG mixtures compared to pure sand. Under saturated and unsaturated conditions, the SRG mixtures demonstrate enhanced bearing capacity. In addition, dynamic response of SRG mixtures to varying cyclic loads are revealed through cyclic triaxial tests. The study confirms the feasibility and effectiveness of using SRG mixtures to improve the mechanical properties of sandy soils, suggesting their potential for diverse geotechnical applications.