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 %).