Effect of Temperature on Hydro-mechanical Behavior of Compacted Expansive soil

ABSTRACT: Temperature effects on the behavior of compacted soil is essential mainly in the landfill barrier materials subjected to elevated temperatures due to bio-chemical reactions of the waste contained. Previous research indicate that subjecting unsaturated fine-grained soils to temperatures below boiling point of water, properties such as volumetric shrinkage, swelling pressure and shear strength are influenced. These changes have been attributed to the thermal variations causing alterations in the physical and chemical behavior at the micro level. This research work is aimed to investigate the effect of temperature on hydro-mechanical behavior of expansive clays under temperatures of 25C, 40C and 60C. The scope of this research is finding variation of hydro-mechanical behavior in physical properties and engineering properties of expansive clay under different temperatures. Experimental findings showed that thermally induced volume change under different temperatures and loads, thermal development of pre-consolidation pressure have direct influence on swelling pressure. It was concluded that elevated temperatures increase swell potential, shrinkage properties as well as compressibility and hydraulic conductivity. The unconfined compressive strength is also studied on the desiccation path of saturated soil at different temperatures and time intervals. The results revealed that both temperature and period of drying have direct influence on the compressive strength. The highest compressive strength is obtained at 4 hours drying at 60C. The results of this research are in good agreement with those in the literature on thermo-hydro- mechanical studies on expansive clay. Keywords: Expansive soils, hydro-mechanical properties, effect of temperature. …………………………………………………………………………………………………………………………