Civil engineering projects are always at high risk of failure when constructed on weak or soft soils due to their lower shear strength and settlement issues. This study summarises the influence of various Nano additives such as Nano aluminium oxide, Nano magnesium oxide, Nano copper, Nano clay, Nano carbons and Nano calcium carbonateon the strength, mineralogical and morphological properties of problematic soils as reported by the researchers. The strength properties such as unconfined compressive strength, direct and triaxial shear strength, and California bearing strength were enhanced with the incorporation of Nano additives up to the optimum amount of dosage in the soil. The very low amount of dosage of Nano additives provided a dramatic change in the strength due to their higher specific surface area as compared to the traditional additives such as cement and lime. The mineralogical and morphological studies showed denser and stiffer soil matrices and depict the formation of new cementitious compounds. From the detailed review of past literature, it can be concluded that the inclusion of a small amount of Nano additives in soil is capable of some shadowing the negative effect of problematic soil for construction purposes.

Because soft clays have a greater tendency to swell and shrink, structures constructed on them face the danger of suffering uneven settlement, which may result in structural damage. Numerous attempts have been made to stabilise the soil by the mean of mechanical and chemical stabilization. In recent years, several researchers intended to change the geotechnical characteristics of problematic soils with the help of Nano-additives such as Nano-silica, Nano-clay, Nano-lime, Nano-carbons. This study is focused on summarising the change in strength, mineralogical and morphological behaviour of soil with the incorporation of Nano-silica and Nano-silica-based compounds reported by researchers. It was observed that strength of soil improved drastically with the addition of Nano-silica and Nano-silica-based compounds up to optimum dosages. The inclusion of Nano-silica densifies soil due to the filling effect, formation of better interparticle bond and pozzolanic products. From the detailed review of literature, it can be concluded that it is advantageous to incorporate Nano-silica and Nano-silica-based compounds to improve the geotechnical properties of problematic soils.