Improvement in the Engineering Properties of Clayey Soil Using Sodium Chloride

Abstract

Major problem faced by civil engineers is when an available site does not have suitable engineering properties to support structures, roads and foundation. The soil of the site may be weak due to number of reasons. A difficult problem in work exists when the soil is found to be clay or the water table in that region is high. Soils with high clay content generally have low shear strength and has tendency to swell when their moisture content is allowed to increase. For these reasons clayey soil is not suited for structures, roads and foundation. Engineering properties of clayey soil can be improved by adopting different methods of soil stabilization. Many stabilization methods are in practice for altering the engineering properties of the clayey soil. Common methods for stabilization of clayey soil are lime and cement stabilization. Soil can also be stabilized by chemical stabilization. Sodium Chloride is the ionic compound of sodium and chloride. A recent study shows that Sodium Chloride can be effectively dissolves in water quickly and provide enough sodium ions for exchange ionic reactions with clayey soil. Function of this chemical (sodium chloride) is to form into cluster of fine particles and bind them together. Sodium chloride dosage is added in 0.5% to 3.0% by weight of soil with 0.5% of increment in each dosage. Standard proctor test, California Bearing Ratio (CBR), consistency limits test and unconfined compressive strength (UCS) test are performed to determine the optimum dosage of Sodium chloride. Tests result indicates that both unsoaked and soaked CBR value of soil increases with the increase in dosage in sodium chloride. Soaked CBR value increases from 4.75% to 9.22% and unsoaked CBR value increases from 8.72% to 13.55% of soil mixed with 2% Sodium Chloride. UCS of the soil increases from 2.75 kg/cm² to 6.33 kg/cm² upon addition of 2% Sodium Chloride. Maximum dry density of soil increases while optimum moisture content(OMC) decreases with increment in the dosage of Sodium chloride up to 2.5% and further decreases. Maximum Dry density (MDD) increases up to 9.02% that of virgin soil. Liquid limit and plastic limit of soil decreases with the addition of Sodium chloride. Liquid limit of soil decreases up to 8.3% as compared to virgin soil. Plasticity index decreases up to 10% as compared to virgin soil.