Experimental Studies on Drying-Wetting Cycle Characteristics of Expansive Soils Improved by Industrial Wastes

The improved engineering properties of the expansive soil by mixing with various additives will be changed during the long-term variation of the meteorological and hydrological conditions. In the present work, a series of tests are performed to investigate the evolution of the unconfined compression strength and the Atterberg limits under drying-wetting cycling conditions for specimens treated by iron tailing sands and calcium carbide slag. Typical results of the unconfined compressive strength can be divided into three stages. The unconfined compressive strength increases initially and then decreases to reach a stable state with continuous drying-wetting process. The calcium carbide slag content (αCCS) of 10% can be determined for the minimum effect of the drying-wetting cycle on the strength of the treated specimen. An exponential relationship is established to describe the evolution of the unconfined compressive strength with the drying-wetting cycle. The liquid limit and plastic index of the specimen increase initially followed by a decreasing trend, while a reverse trend was observed for that of the plastic limit during the drying-wetting process. The minimum effect of the drying-wetting cycle on the Atterberg limits can be presented for the specimen with αCCS of 10% as well.