The objective of this work is to analyze the effect of some salts at different concentrations (Nitrate, Sulfate, and Phosphoric Acid) on the physical and mechanical parameters of a clayey basement soil. Saline solutions were prepared by dissolving salts in demineralized water. These salts were chosen because they are common in the composition of the pore water clay formations in the region. The tests carried out for this study are plasticity tests (Atterberg limits), Proctor tests and CBR load-bearing tests. Plasticity tests (Atterberg limits) show that the increase in the concentrations of salts (sulfate, nitrate, and phosphate) induces a significant decrease in the liquid limit of the clayey soil. Proctor tests show that adding salts to the clayey soil leads to an increase in dry density and a decrease in water content. In the case of CBR tests, when the clay soil is unsaturated (drought period), the salts do not significantly influence the soil’s bearing capacity: the CBR index recorded using the immediate CBR test is almost the same as that of clay alone. On the other hand, in the saturated state of the clay, a low concentration of salt solutions increases the CBR indices immediately and after immersion and improves the clay’s bearing capacity. These different results show that the behavior of the acidified clay material depends on the salt concentration and the nature of the salts, which greatly influence the plasticity and bearing capacity of the clay soil.