Effect of Physico-Chemical Interactions and Cyclic Wet–Dry Process on Behaviour of Compacted Expansive Soils

Abstract

Physico-chemical interactions and alternate wetting and drying process have marked influence on the swell–shrink and hydraulic behaviour of compacted expansive soils used in various engineering applications. The microstructural, shrinkage cracks pattern and hydraulic behaviour of compacted expansive soils get altered due to the interactions with leachates and cyclic wet–dry process. Therefore, the effect of concentration of leachates and cyclic wetting–drying process on the swell–shrink, shrinkage cracks, microstructural and hydraulic behaviour of compacted expansive soil is studied in this theme lecture paper. The shrinkage cracks developed in clay specimen during a drying cycle were quantified using the X-ray computed tomography images and vernier caliper height measurement. And the same method was used to quantify the cracks in desiccated specimens interacted with different concentrations of interacting fluid. Scanning electron microscope and mercury intrusion porosimeter studies were carried out to understand the microstructure of salt solution-interacted specimens. The influence of physico-chemical interactions and cyclic wet–dry process on the self-healing capacity of compacted expansive soil specimens was brought out by carrying out hydraulic conductivity tests.