Thermal volume changes of the mineral–water system in low-porosity clay soils

Abstract

The effect of temperature on the volumetric strains of the clay skeleton and clay – water system has been examined experimentally. Heating tests at (various) constant effective stress and isotropic loading tests at (various) constant temperatures were performed on low-porosity clays under drained conditions. The results indicate that the thermal expansion of adsorbed water in these clays is significantly lower than that of free water. Depending on the effective pressure, the clay skeleton may undergo either compression or expansion. Key words: nuclear waste isolation, clay, low porosity, thermal strain, adsorbed water.