Performance Prediction Model for Manganese Slag-Based Grouting Materials

To provide a basis for the resource utilization of manganese slag solid waste and address geotechnical reinforcement challenges, this study focuses on the core engineering properties of manganese slag-based grouting materials using the COMSOL Multiphysics numerical simulation platform. It emphasizes analyzing their diffusion patterns within rock and soil bodies, multiphysics coupling mechanisms with rock and soil, and reinforcement mechanisms in water-rich karst regions. By establishing a “fluid flow—mass transfer—rock deformation—chemical cementation” multiphysics coupling model, incorporating physicochemical parameters of manganese slag particles (density 1800–2000 kg/m3, dynamic viscosity 0.002–0.005 Pa·s), this study reveals the influence mechanisms of grouting pressure, water-cement ratio, rock/soil pore structure, and groundwater velocity on grout migration and reinforcement effectiveness. These findings are consistent with previous studies demonstrating that manganese slag-based cementitious systems exhibit strong coupling behavior between hydration reactions and mass transport processes, significantly affecting mechanical performance and environmental stability [1]. In water-rich karst regions, “dynamic viscosity control” is required to suppress groundwater dilution effects, with post-grouting cohesion of rock and soil bodies increasing by 30%–50%. This phenomenon is in agreement with findings that slurry viscosity and sulfate-induced hydration products (e.g., AFt and C-S-H) play a critical role in controlling diffusion behavior and enhancing structural integrity under dynamic water conditions [2].