Research on the Rheological Properties and Diffusion Law of Coal-Based Solid Waste Geopolymer Grouting Material

The rheological properties and diffusion law of coal-based solid waste geopolymer grouting material (CGGM) slurry were investigated by rheological property test and diffusion theory model derivation. Based on the power-law fluid constitutive equation, a theoretical model of slurry diffusion in an inclined fissure aquifer was established, and the effect of slurry grouting time on the slurry diffusion distance under different fissure widths, fissure inclination angles, and grouting pressures were analyzed. The results show that when coal gangue:cement:fly ash = 5:4:1, sodium silicate modulus 2.0, sodium silicate content is 10%, CGGM slurry's bleeding rate of 1%, the liquidity of 227 mm, the initial and final setting time is 412 min and 825 min, respectively, to meet the requirements of the grouting project. CGGM slurry is a typical viscosity time-varying power-law type fluid, and the slurry diffusion distance is positively correlated with the grouting pressure, fissure width, fissure inclination angle, and negatively correlated with the rheological index. The established theoretical model can provide a reference for the parameter design of CGGM slurry in grouting construction.