The Influence of Sodium Chloride on the Strength

In many regions with evaporated geological structure, soil usually contains a significant amount of soluble salts. These salts affect soil structure and shear strength, and also the performance of additives which are usually used to strengthen the soil. Soil stabilization by lime is one of the common methods of soil improvements which has been known and used from far periods. In most parts of Iran, especially in tropical areas, sodium chloride exists naturally in the soil which by the way of weak ionic link causes slight reinforcement of resistance nearly. Since the weak ionic band can break down quickly by a minor loading; it is necessary that more research be carried out on the stabilization of this kind of soil. In this study, the effect of sodium chloride with different mixing ratio has been studied. The results of unconfined compressive strength show that the presence of sodium chloride after 7 days causes a reduction in the resistance of samples, while it increases the resistance after 28 days if the percentage of salt is less than 1%.