Influence of Temperature on Strength and Elastic Stiffness Behaviours of Ottawa Sand under Triaxial Compression Test Temperature on Strength and Elastic Stiffness Behaviours of Ottawa Sand under Triaxial Compression Test

The aim of this study is to investigate the influence of temperature on the shear strength and elastic stiffness of sand under triaxial compression (TC) test. Air-dried Ottawa sand specimens were prepared to avoid pore pressure induced during shearing. Ottawa sand, widely used in geotechnical engineering research, was selected for these TC tests. The sample was first drained and then heated to different target temperatures (i.e., 30, 45, and 60°C), which were maintained constant during the tests. After heating, the sample was sheared under a constant cell pressure and temperature. Small strain-amplitude cyclic loading was applied successively at different shear stress levels to investigate the elastic Young’s modulus (Eeq) behaviour. The results revealed that the peak shear strength increased with increasing temperature. For Eeq values, a clear relationship with temperature was observed, indicating that elastic stiffness of Ottawa sand also increased with temperature. These findings are significant as they demonstrate that temperature variations can markedly affect the mechanical behaviour of sand, which is important for understanding and predicting the performance of geotechnical structures subjected to thermal effects. Moreover, a sudden drop of stress can be observed as a phenomenon commonly observed in round particle shapes.