Influence of heat treatment on the behavior of clayey soils

This study examines the effect of temperature under laboratory conditions of three clayey soils collected from northern Jordan. Soils were subjected to four temperature levels, i.e. 100, 200, 300 and 400 degreesC. Various soil properties were studied including Atterberg limits, particle size distribution, optimum water content, maximum dry density, swelling potential, and unconfined compressive strength. Experimental results revealed that heat treatment higher than 100 degreesC resulted in a decrease in liquid and plastic limits, optimum water content, unconfined compressive strength, and swelling pressure of soils tested. However, maximum dry density increased slightly with an increase in temperature to reach a maximum value of 14.3 kN/m(3) at 400 degreesC for soil-1 compared to 12.9 kN/m(3) at ambient temperature. Heating the clayey soils at 400 degreesC decreased the liquid limit, plastic limit, optimum water content, swelling pressure, and unconfined compressive strength by 80%, 100%, 65%, 94%, and 100%, respectively, in average compared to soil specimens at ambient temperature. (C) 2001 Elsevier Science B.V. All rights reserved.