Mechanism and Engineering Characteristics of Expansive Soil Reinforced by Industrial Solid Waste: A Review

Abstract

Expansive soils exhibit detrimental swelling and shrinking characteristics in response to variations in water content, posing a threat to engineering safety. Utilizing industrial solid waste for improving the engineering properties of expansive soil presents a promising solution due to its low pollution and high recoverability. This paper reviews the progress of research on various industrial solid wastes in stabilizing expansive soil. The review comprehensively discusses the microscopic characteristics and mechanism of industrial solid waste-stabilized soils, as well as their impact on the compressive strength, shear, compaction characteristics, consistency, swelling and shrinkage properties, and durability of expansive soils. The addition of appropriate curing agents or the combination with other stabilizing materials can enhance the strength of expansive soil, mitigate volume changes, and improve the durability and stability of expansive soils. The mechanisms of stabilization of expansive soils by industrial solid waste involve cation exchange, flocculation-agglomeration, pozzolanic reaction, and carbonation. Additionally, microscopic characterization analysis reveals that the formation of C-S-H and C-A-H is the primary contributor to the improvement of soil geotechnical properties.