Stabilization of Fine-Grained Soils Against Desiccation Cracking Using Sustainable Materials

Desiccation cracking is a phenomenon commonly associated with the fine-grained soils, which initiates at their surface and subsequently propagates deeper inside their matrix. Hence, for safe and durable infrastructure development, stabilization of such soils becomes important. In order to stabilize these soils, cement, chemicals, and fibers have been employed by earlier researchers. However, in recent times, the ill effects of these stabilizers on the ecosystem have been realized, and hence their replacement with sustainable materials that are mostly industrial by-products is becoming necessary. This philosophy would not only conserve natural resources, but would also result in a “marriage” between “two suitable” materials to create a “synergy” within the ecosystem. With this in view, the ground granulated blast furnace slag (GGBS), a by-product from the iron and steel plants, was activated by red mud (RM), a by-product from alumina manufacturing units, with an objective to establish its utility in stabilizing the fine-grained soils against desiccation cracking. To achieve this, the parameter crack intensity factor (CIF), which has been employed by earlier researchers to quantify cracking characteristics of the (virgin) soil mass, has been employed for the soils amended with GGBS and RM. Subsequently, the CIF has been correlated with the soil specific parameters (viz., cation exchange capacity and tensile strength) and the environmental conditions (viz., humidity and temperature), represented by the evaporation rate of the soil mass. Based on these extensive investigations, it has been demonstrated that such correlations would be very useful for selection of the right combination of the soil and sustainable material(s) to achieve a stabilized system of the fine-grained soil. It has been put forth through this study that the by-products chosen exhibit high potential to stabilize the fine-grained soils, which also resulted in alteration of their micro-structure and strength post stabilization. Furthermore, studies have been carried out to establish the effect of addition of industrial by-products to virgin soils, mainly in terms of their micro-structure, which in turn controls their strength.