Experimental study on combined stabilization technology of electrochemical grouting-carbonation for soft soil ground

The stabilization technology for soft soil ground under the carbon peaking and carbon neutrality goals is a hot topic in recent years. A new technology of electrochemical grouting combined with CO₂ carbonation to strengthen soft soil foundation is introduced, that is, in the electrochemical grouting process, the CO₂ gas is injected into the soil by using the aerating equipment for carbonation and solidification to improve the strength of soft soil foundation quickly and greatly. Through the laboratory model tests, 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 the soft soil ground. The micro-cementation of soft soil after the combined treatment of electrochemical grouting carbonation is investigated through the scanning electron microscope tests, and its micro-reinforcement mechanism is revealed. The test results show that the combined reinforcement of electrochemical grouting and carbonation for the soft soil foundation with depolarized CaCl₂ solution and Na₂SiO₃ solution is better than the traditional electrochemical grouting stabilization method, the undrained shear strength of soil increases greatly, and the contribution of carbonation accounts for half of the total growth undrained shear strength. It is shown that the proposed technology has both carbon sequestration and soft soil solidification effects, which is of great significance for the low-carbon development of foundation stabilization.