Nano-Chemical Stabilization of Soft Soil as a Paved Subgrade Material

Soft soils are fragile in supporting the paved infrastructures, causing severe differential settlements and lateral displacements. Due to higher water contents, the soft subgrade soil becomes more compressible with overlying road pavement layers. Therefore, it is necessary to stabilize the soft subgrade soils to improve the geotechnical properties before constructing the road infrastructure. Nowadays, the ground profiles stabilize after using various commercially available nano-chemicals. Compared with traditional stabilizing methods, non-traditional nano-chemical treatment has the advantages of lower cost and better environmental protection. The present study initially characterized the clay soil for its basic geotechnical properties. Further, a series of experiments were conducted to study the effect of organosilane nano-chemicals on consistency limits and CBR strength with different curing periods. Herein, nanotechnology-based organosilane compound (Terrasil) is introduced into the cemented clay soil at 1% cement binder in different amounts of 0.03–0.05% for stabilization. XRD and SEM tests were conducted to discern the latent mechanisms and study the soil matrix’s physicochemical changes. The focus of this study was to determine the optimal dosage of nano-chemical corresponding to maximum CBR strength at different curing periods. The results indicated that the strength of stabilized clay soil increased with the increase of nano-chemicals up to a specific dosage and further decreased. Optimal results were obtained for soil treated with 0.045% nano-chemical and 1% cement. XRD and SEM results postulated the evidence of the furtherance in cementitious activity within the soil matrix.