Experimental study of electrochemical-carbonation combined foundation stabilization technology in soft clay ground

Soft soil ground stabilization technology under the carbon peaking and carbon neutrality goals is a hot topic in recent years. In this paper, a new technology of electrochemical grouting combined with CO2 carbonation to strengthen soft soil foundation is introduced, that is, in the electrochemical grouting process, CO2 gas is injected into the soil by aerating equipment for carbonation and solidification, to improve the strength of soft soil foundation quickly and greatly. Through the laboratory model test, the undrained shear strength of the soil treated by the proposed method is compared with that of the soil treated by the electrochemical grouting method, and the soil conductivity and soil pH value in the process of stabilization are measured, which demonstrates the superiority of this technology in strengthening soft soil ground. The micro cementation of soft soil after electrochemical-carbonation combined treated was investigated by scanning electron microscope test, and its micro reinforcement mechanism is revealed. The test results show that the electrochemical grouting and carbonation combined reinforcement of soft soil foundation with depolarized CaCl2 solution and Na2SiO3 solution is better than that of traditional electrochemical grouting stabilization method, the undrained shear strength of soil is increased greatly, and the contribution of carbonation accounts for half of the total growth undrained shear strength. The study suggests that this technology has both carbon sequestration and soft soil solidification effects, which is of great significance for the low-carbon development of foundation stabilization.