Stabilization of Expansive Soils Using Non-conventional Waste Stabilizers: A Review

Expansive soils are one of the most widely found soils across the globe. Due to containment of swelling minerals in considerable proportion with net electronegative arrangement of ions, these clays possess extraordinary ability to absorb water resulting in low-strength and high-swelling structure of soil. These soils produce some of the major ill effects in the structural elements constructed over them due to their high activity and volume change behaviour, seriously hurting the utility of the structure. Chemical stabilizers have proved to be satisfactory modifier of the inherent structure of the soil. Although the conventional stabilizers such as lime, cement and fly ash have shown their ability to successfully enhance the utility of the soils for engineering purposes, their rising cost and environmental concerns including their carbon footprint have led researchers to focus on the more sustainable and environment-friendly form of stabilizers which could replace the former ones. This paper presents a summarization of the research works carried out in the recent past to counter the unwanted behaviour of expansive clays with the use of non-conventional waste products as potential stabilizers. In addition, the stabilization mechanism, field application, durability and possible environmental impact have also been addressed to present an overall picture of their future potential in stabilization of expansive soils.