Simulation study on the splitting grouting and compressive properties of fiber-reinforced cement tailings sand-based materials

To further investigate the diffusion properties and strengthening mechanisms of fiber-reinforced cement tailings sand-based grouting materials (FRCTGs), this study conducted laboratory grouting diffusion tests. A mesoscopic mechanical model under splitting grouting and uniaxial compression conditions was established via PFC 2D 6.0 software, and a comparative analysis of the grout propagation patterns and reinforcement effects between pure ordinary Portland cement-based grouting materials (POPCGs) and FRCTGs was conducted. These results indicate that the FRCTG exhibited a superior diffusion state. In the splitting grouting simulation, FRCTG demonstrated significant rheological advantages, generating 4.5% more cracks than POPCG, and a multilevel secondary grout network formed at the crack bifurcation points. The compression characteristic simulation indicates that POPCG exhibits a faster hydration reaction in the early stages, effectively enhancing the integrity of the rock mass and limiting the formation and propagation of cracks in the short term. After 56 d of curing, the compressive strength of FRCTG increased faster than that of POPCG, with its later hydration products continuously crystallizing to form a dense structure, significantly outperforming the long-term strength of pure cement-based materials. The research results provide a reference solution for reinforcement projects requiring high durability, such as dam foundations and surrounding rock.