Experimental Study on Temperature Effect on Engineering Properties of Clayey Soils

Abstract

Temperature significantly influences the engineering properties of clayey soil and this temperature effect usually depends on soil type. In this investigation, laboratorial experiments were conducted on three soils to evaluate the adsorbed water content, Atterberg limits, swelling, shear strength and permeability under different temperatures (5-50°C). The results indicate that liquid limit decreases, swelling increases, permeability increases with increasing temperature. It is fundamentally due to the change of adsorbed water content. Hydrophilic minerals, which contain large amounts of adsorbed water, play an important role in the temperature effect. With the increase of hydrophilic minerals, the temperature effect on liquid limit increases and the effect on swelling ratio decreases. The hydrophilic minerals content also has significant impact on the temperature effect of permeability. With increasing temperature, the adsorbed water is transformed to free water, and then the permeability may increase significantly. The shear strength of clayey soils with higher content of hydrophilic mineral is more sensitive to temperature variation. The cohesive force mainly changes linearly with the temperature. Different phenomena, i.e. thermal-hardening or thermal-softening, was observed on strength behaviour due to different hydrophilic mineral content, moisture content and dry density of sample.