Numerical Analysis of Slurry–Crack Coupling in Grouting Repair Process of Multiple Cracks in Concrete Material

The interaction between slurry and concrete cracks influences the grouting diffusion process during the grouting repair engineering of cracked concrete material. Compared to a single-cracked concrete material, the slurry-concrete crack interaction mechanism of a multi-cracked concrete material is more complicated. This study employs the Monte Carlo method to generate a crack group with a certain probability distribution for characterizing the random cracks in the concrete material. The cracked concrete material is simplified as a pore-crack medium model, and the continuity equation of the slurry in the model is derived. Furthermore, based on the modified interface layer theory, the coupling effect of the slurry-concrete crack is elucidated, and the variation law of each crack opening in the concrete material under different grouting pressures is examined. When the slurry diffuses in a multi-cracked concrete material, the crack opening changes mainly stem from the crack distribution position and crack tendency. Under the same grouting pressure, four main forms of changes occur in the crack opening: gradual increase along the crack distribution, slow decrease, first increasing and then decreasing, and, basically, unchanged. When the grouting pressure increases, crack groups with the same distribution form have similar crack opening change rules, but the change range varies. Under the same grouting pressure, as the number of cracks in the concrete material increases, the coupling effect of the concrete material becomes increasingly obvious.