EXPERIMENTAL ON THE PERFORMANCES OF SHIELD SLURRY SOLIDIFIED SOIL THROUGH A NEW CURING AGENT BASED ON SOLID WASTE

Using low-quality diatomite, phosphogypsum, and carbide slag as raw materials, with traditional lime-fly ash as the control curing agent, experiments were conducted to evaluate the boundary moisture content, permeability, unconfined compressive strength, water stability, dry-wet cycle resistance, and heavy metal leaching characteristics of solidified shield tail slurry. The curing effects of the novel curing agent and diatomaceous soil on the shield slurry were systematically compared. Carbon emission indicators were introduced to assess the environmental impact of the new curing agent. Test results indicate that the boundary moisture content of the shield slurry gradually increases with higher curing agent content. The soil treated with the novel curing agent exhibits improved mechanical properties and durability. At a curing agent content of 8%, the material meets the requirements specified in relevant standards for use as pavement base filler. Strength loss of the modified solidified soil under dry-wet cycling primarily occurred during the first two cycles, after which it stabilized. In contrast, the lime-fly ash solidified soil disintegrated after three dry-wet cycles. In terms of carbon emissions and strength performance, compared to cement and lime-fly ash, the novel curing agent reduces CO₂ emissions by 76% and 81%, respectively, per unit strength improvement of the solidified soil. This demonstrates significant environmental benefits and aligns with the current"dual carbon" goals.