Effects of chemical stabilizers on an expansive clay

Expansive clays exhibit a high potential for the volume change behavior when the soil moisture changes. The estimated annual cost of the damage to the facilities built on expansive clay in the United States exceeds 9 billion dollars. Because of the physicochemical nature of the expansive clay, the use of chemical agents to improve their engineering properties is common. This research investigated the effects of chemical agents on an expansive soil from Texas through a laboratory injection method. The agents used in this study included lime, potassium based agents, and a group of ionic agents. Swelling tests, chemical tests, and soil suction tests were used to evaluate the stabilizing effects of those chemical agents. The testing results indicated that potassium based stabilizer, is an effective stabilizing agent to control the swelling potential of the expansive clay. It can also be injected in the field to build a moisture barrier. The chemical tests on the injected Texas clay showed that the stabilizing mechanism of the ionic agents is possibly through the cations’ exchange and the increase of the cations’ concentrations in the soil pore water.