Some Aspects of the Effect of the Temperature on the Behaviour of Unsaturated Sandy Clay

Summary

The paper describes experimental results on triaxial paths at high temperature concerning an unsaturated clay (w_L = 38%, I_P = 19 and C_c = 0.23). Unsaturated drained triaxial compression tests on normally consolidated samples were carried out at constant temperatures varying from 22 to 80˚ C. Desaturation of samples were carried out by the imposition of suctions using the osmotic method. This required the development of a new triaxial cell equipped with a collar heating and an osmotic pedestal which allows the circulation of an osmotic solution of Poly Ethylen Glycol (PEG) 6000, in contact with the sample via a dialysis membrane. The principal phenomena simultaneously related on the temperature and saturation were highlighted, in particular the hardening of material on isotropic path, a secant modulus which decreases with temperature and increases with suction, a light reduction in the maximum stress on deviator path at high temperature and the increase in this maximum stress when suction increases.