A Laboratory Evaluation of Stabilization of Silty Clay Soil by Using Chloride Compounds

Abstract

Large areas of Iraq consist of soils with high clay contents which have low strengths and bearing capacity.This problem has an influence on construction of road and highway, if adequate support does not exist, the road will rapidly deteriorate. The solution to these construction problems is by soil treatment with chemical additives. The main objective of this study is to investigate effectiveness of salts used as an additive in stabilization of silty clay soil. Three types of salts used which are sodium chloride (NaCl), magnisum chloride (MgCl2) and calcium chloride (CaCl2). Various amounts of salts (2%, 4%, and 8%) were added to the soil to study the effect of salts on the consistency limits, compaction characteristics and CBR value.The test results indicated that the liquid limit, plastic limit and plasticity index decreased as the salts content increased. The addition of salts to the soil increased the maximum dry density and reduced the optimum moisture content. The addition of (2 %) salt to the soil causes increases the CBR value between (8 to 28 %), while, in samples containing large amount of salt (4 and 8 %) the increase was between (55 to 80%).The CBR value increased as the salt content increases for different type of salt and the greatest value is found in the soil treated with (4%) calcium chloride which was equal to (80 %).

Keywords

• soil stabilization
• silty clay soil
• chloride compounds
• cbr