Hang Xu, Qian Bai, Guoliang Xie
Grouting materials can be used for reinforcement and water plugging of underground engineering in sandy strata. This study examines the mechanism of alkali-activated cementitious materials by selecting steel slag and ground slag to replace cement in double-liquid grouting materials. Various retarders were used to adjust the gel time, making it controllable for grouting materials. The results show that when the sodium silicate volume is in the range of 20–40%, the W/B is in the range of 0.7–1.0, and the steel-slag-to-ground-slag ratio (SS:SL) is 3:7, the macroscopic properties of the grouting material reach the optimal value, the microstructure is denser, and the hydration products are calcium hydroxide, calcium–silicate–hydrate (C-S-H) gel, and ettringite. When the cement content is 40%, the W/B is 0.8, the sodium silicate volume dosage is 30%, and the SS:SL ratio is 3:7, the 3 d compressive strength of the slurry reaches 14.57 MPa and the 28 d compressive strength reaches 21.14 MPa. To analyse the solidification effect of double-liquid grouting materials with mixed SS and SL on sandy soil, experiments were conducted to study the impacts of the soil moisture content, soil particle size distribution, and slurry quantity on the strength of consolidation. This study conducts an in-depth investigation into optimising the proportioning of industrial solid wastes and the multi-component synergistic mechanisms. This study provides a new method for the effective utilisation of industrial waste and a reference for the practical application of industrial waste as supplementary cementitious materials in the future.