Thermo-mechanical response of sand-silt mixtures

The thermo-mechanical response under undrained conditions is crucial in evaluating the mechanical behaviors of sand-silt mixtures. A series of consolidated undrained triaxial shear tests were conducted to investigate the mechanical response of sand-silt mixtures with different fines contents, temperatures, and initial mean effective stresses. The results showed that the volume shrinkage was observed in all specimens during heating. The amplitudes of volume shrinkage were dependent on the fines content and initial mean effective stress. Moreover, the fines content and temperature significantly influence the peak strength, flow behavior, stress ratio at the undrained instability state, and collapsibility index. Furthermore, a unified critical state line has been established in the compression plane for both clean sand and binary mixture under different temperatures and fines contents. It is reliable and suitable to use the equivalent skeleton void ratio to illustrate the thermo-mechanical response of sand-silt mixtures under undrained conditions.