Strengthening the subgrade clay soil using nano chemical stabilisation

Nowadays, non-traditional eco-friendly nanomaterial additives are widely utilized in the geotechnical stabilization of soft soils. The application of materials developed using nanotechnology in stabilizing soils effectively reduces or replaces the utility of cementation products like cement and lime, which leads to environmental pollution. This article evaluates the efficacy of organosilane nano-chemical additive with 1 % cement binder in improving the strength properties of soft soil used for road-based applications. A series of experimental tests were conducted to characterize the geotechnical properties of soft clay and nano-chemical-treated soft soils with 1 % cement binder, including soil gradation, consistency limits, compaction, unconfined compression, and California bearing ratio (CBR) strength, and microstructural and chemical analysis. A small dosage of 1 % cement was added to the parent clay to accelerate the cementitious reactions in soil treated with a nano-chemical additive. The dosage of nano-chemical additives used was varied from 0.03 to 0.05 % for the present study. The treated clayey soil is examined for the optimum dosage corresponding to the highest unconfined compression strength of soil samples cured up to 28 days. Test results show that the soft clay treated with organosilane-based nano-chemical at an optimum dosage of 0.045 % and 1 % cement binder has attained the maximum unconfined compression and CBR strengths. SEM and FTIR results postulate the microstructural and chemical interactions involved in supporting the mechanism of improvement in the strength of treated soils.