Influence of temperature on the retention capacity of clay liners during wetting and drying

Abstract

Sand-clay mixtures are common materials used in several engineering practices. Liner layers and cover layers in waste management facilities are normal examples. When existing in unsaturated conditions, these layers are exposed to moisture as well as temperature fluctuation. Knowledge of the relationship between soil suction and water content for these materials is very essential to understand the unsaturated soil behavior and associated properties such as retention capacity and unsaturated water flow (hydraulic conductivity). As a general scope of this study, the retention capacity during drying-wetting cycles is investigated for two sand-natural-expansive clay (SEC) mixtures (15% and 30% expansive clay) at different ambient temperatures of 7 °C, 24 °C, and 47 °C. Drying-soil and wetting-soil water retention curves for these materials were determined at selected ambient temperatures using different salt solutions for entire range of suction (up to 300 MPa). The effect of temperature variation on the retention capacity during drying-wetting conditions was highlighted and discussed; volume changes associated with suction were also measured and assessed. The findings of this study revealed that the effect of temperature on retention capacity of SEC liners is suction range as well as clay-content dependency and is more evident at the drying path rather than wetting path.