The Effect of Acidic and Alkaline Chemical Solutions on the Behavior of Collapsible Soils

In this research, the effect of acidic and alkaline chemical solutions on the behavior of loessial soil was investigated. To evaluate the severity of acidity and alkalinity of chemicals, two factors sulfuric acid and sodium hydroxide were used in the pH of 3, 5, 9, 11. In this research, the effect of acidic and alkaline solutions on the collapse potential, shear strength parameters and unconfined compression of collapsible soils were investigated. Experimental tests results showed that acidic solutions with a low pH increase the collapse potential and effective cohesion of soil and decrease effective internal friction angle; on the other hand, alkaline solutions with a high pH decrease the collapse potential and effective cohesion of the soil and increase effective internal friction angle. The results of unconfined compression tests showed that with increasing the acidity and alkalinity in soil, the undrained strength of the soil decreased. SEM test results showed an increase in soil cavities in acidic solution while the soil cavities were fixed in alkaline solution.