Preparation, characterization, and rheological analysis of eco-friendly geopolymer grouting cementitious materials based on industrial solid wastes

Geopolymer grouting materials has been applied in underground engineering as a reinforcement material. At the same time, with the enhancement of human environmental awareness, low carbon environmental grouting materials have attracted widely attention. Therefore, this study used industrial solid wastes circulating fluidized bed fly ash (CFBFA), calcium carbide slag (CS), and flue gas desulfurized gypsum (FGDG) as the main raw materials to prepare eco-friendly geopolymer grouting materials. The compressive strength, setting time, fluidity and stone ratio analysis were systematically evaluated. Finally, the microscopic experiments, including X-Ray Diffraction, CT scanner, TG/DTG analysis, and Scanning Electron Microscopy (SEM), were conducted to investigate the mechanism of geopolymer grouting reinforcement materials based on CFBFA, CS and FGDG. The results showed that the solid-wasted grouting materials have a 28d compressive strength of 20.5 MPa, the stone ratio of 99.8%, the fluidity was 250 mm. And adding the 6% alkali activator may enhance the system's fluidity and setting time. In summary, this study analyzed the viability of producing high performance grouting materials for subterranean engineering utilizing industrial solid wastes CFBFA, CS, and FGDG, which are expected to be an alternative for cement as an eco-friendly grouting cementitious material.