Assessing the Geotechnical Properties of Lime-Stabilized Black Cotton Soil in the Presence of Nanosilica

Expansive soils present substantial challenges in civil engineering because they undergo volume fluctuations with changes in water content, mainly affected by the clay mineral montmorillonite. Nanotechnology has rapidly and widely improved, finding applications across all engineering fields. This study focused on enhancing soil engineering performance using lime alone and the impact of varying quantities of nanosilica with lime in the soil, focusing on engineering parameters like Atterberg limits, maximum dry density, optimum moisture content, and unconfined compressive strength over curing periods of 7, 14, and 28 days. In this study, the basic properties of soil were initially determined. Then, lime was mixed with soil in different proportions of 2%, 4%, 6%, and 8% according to the dry weight of the soil. Based on strength criteria, soil mixed with 4% lime gives the best results. Keeping the lime content constant at 4%, nanosilica was added to the soil. These findings suggest modifications in the amended soil’s plasticity, compaction characteristics, and strength with the minor addition of nanosilica to lime-mixed black cotton soil. The enhancement in strength of expansive soils relies on the amount of lime and nanosilica and the duration of curing. After conducting tests, it was found that the optimal quantities for lime and nanosilica through strength performance tests are 4% and 3%, respectively. The research asserts that adding nanosilica to lime notably improves the mechanical properties of black cotton soil. Scanning electron microscopy and X-ray diffractometer analyses support these findings, revealing variations in the character and strength of the CSH phase over curing time. These conclusions offer wide-ranging relevance for projects seeking to enhance the engineering properties of soft soils.