Experimental Assessment of Geotechnical Properties of Nano-Clay-Stabilized Soils: Advanced Sustainable Geotechnical Solution

The usage of locally available soil for construction purposes is a wise choice for enhancing its engineering properties. Depending on the size of the particles, the silty and clayey soils possess voids at the nano level. Generally, clay soil is affected by increased settlement, decreased stability and altered soil structure due to the increased plasticity index. Hence, it is necessary to enhance the soil properties using various additives. In recent days, nanomaterials have been increasingly utilized for improving soil stability and strength in various geotechnical engineering applications. This paper deals with the effect of nano-clay on the various geotechnical properties of three different silty and three different clayey soil samples. The influence of the wet–dry cycles on the unconfined compressive strength (UCS), coefficient of permeability (k) and settlement were discussed. Furthermore, the UCS and California bearing ratio (CBR) of the nano-clay-treated soil were predicted by using multiple regression analysis based on the index properties. Test results revealed that the optimum dosage of nano-clay was found to be 0.4%, 0.35%, 0.35%, 0.25%, 0.25% and 0.2% for three different silty soil samples and three different clayey soil samples, respectively. The UCS and CBR values were enhanced significantly irrespective of the nano-clay content and the soil type, due to the formation of CSH gels that effectively bonds the soil particles and facilitates the improvement of UCS and CBR and thus reduces the ‘k’ and settlement of soil samples. The predicted UCS and CBR values by regression analysis are in line with the experimental results in both treated and untreated conditions. As a result, this amorphous nano-clay is recommended for stabilizing weak soils irrespective of the type of soil.