Experimental Study of Physio-Mechanical and Engineering Properties of Clayey Soil Incorporating Hydraulic Lime and Nano-Silica

Abstract

Soil is one of the most abundant and frequently used materials in geotechnical engineering and construction. Soil is heterogenous material with different minerals some of which are classified as problematic minerals. The soil is classified as unacceptable for construction purpose if some of these minerals are present in the soil. Soil improvement utilizing nano materials is a novel technique to upgrade engineering and shear strength parameters of problematic soils. The effects of varying amounts of nano-silica and lime in clayey soil are investigated in this study. For this purpose, soil samples were moulded by incorporating 0, 3, 6, 9% nano silica and 0, 5, and 10% lime. The samples were tested for Atterberg limits, Plasticity index, optimum moisture content OMC, maximum dry density MDD, swelling, and unconfined compressive strength (UCS) at 7 and 28 days. The results revealed that addition of nano-silica in lime treated high plastic clay improved the plasticity index as well as UCS and swelling behaviour by a significant margin. Results highlighted that incorporation of nano silica reduced the plasticity index. UCS values of the soil increased by adding nano silica 28 days UCS increased by 10 times as compared to 7 days strength. The swelling in soil samples with 10% lime and 9% nano silica is reduced by almost 32% as compared to controlled samples. OMC is also increased by 17% meanwhile MDD is reduced by 9% when nano silica was added. The findings of this study can be used in any project that requires improved engineering and geotechnical properties of high plastic clayey soil for shallow foundations