Microstructural investigation on the expansive soils for sustainable stabilization purposes
S. Selvakumar, B. Soundara, Neha Raj, Ponnusamy Kulanthaivel
Abstract
Expansive soils are difficult to handle due to their high potential for volume changes, leading to structural damage. This study aims to characterize the microstructural and mechanical properties of expansive soils for sustainable stabilization purposes. Advanced analytical techniques were used including X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray (SEM-EDX), thermogravimetric analysis (TGA), differential thermal analysis (DTA), Fourier transform infrared spectroscopy (FTIR) and other mechanical tests. The XRD identifies and quantifies the swelling clay minerals influencing volume change behaviour. SEM-EDX shows observable particle morphology, microstructure, and semi-quantitative elemental composition. TGA and DTA provide thermal information including phase changes with respect to the varying temperature of the soil sample. FTIR identifies and computes organic functional groups and their bondage. Finally, the mechanical test provides information on compactibility, strength and volume change characteristics. The results of the study indicate that comprehensive microstructural characterization provides insights into the soil behaviour which can be used in practical application to select appropriate methods of stabilization avoiding adverse effect to the infrastructure. Moreover, these findings underscore the importance of micro-mechanical characteristics of expansive soils and promotes sustainability in soil stabilization practices.