Study on the effect of calcium carbide slag based alkali activator on the properties of fly ash synchronous grouting materials

In order to promote the resource utilization of industrial solid waste carbide slag, while reduce related pollution problems, and synchronize grouting costs. This paper uses carbide slag as an active activator for fly ash synchronous grouting materials. In response to the problem of poor early strength in the preparation of cementitious materials by mixing calcium carbide slag and fly ash, this experiment added sodium sulfate and water glass to prepare alkali activated fly ash synchronous grouting. Orthogonal experiments are conducted using calcium carbide slag, sodium sulfate, and water glass as different factors to analyze the sensitivity and regularity of the above factors on various experimental parameters of the slurry. Multiple linear regression analysis is performed to predict and the Gauss algorithm is used to optimize the preparation model. The results show that calcium carbide slag reduced the early working performance of the slurry, but improved the later strength of stone body. The addition of water glass improved the early performance of the sample. The optimal material ratio is ultimately determined to be 18.6% for carbide slag, 2.7% for sodium sulfate and 0.6% for sodium silicate. The compressive strength after 28 d can reach 10.89 MPa. XRD and SEM analysis show that a large amount of hydration products are generated with the increase of curing age during the hydration of materials, making the grouting combination have higher compressive strength in the later stage.