Three‐dimensional simulation and performance control of a wet packing system with ultra‐fine stone powder and cement particles

Abstract The “paste replacement method”—which replaces cement paste with stone powder—enables the maximum reduction of cement consumption without compromising, or even enhancing the performance of cement‐based materials. This mechanism is attributed to the filling and nucleation effects of stone powder; however, there remains a lack of visualized studies on how to efficiently quantify its filling effect to further regulate the packing system and material properties. Therefore, in this study, ultra‐fine powder with an average particle size smaller than that of cement was used as the filler, and a three‐dimensional discrete element method (DEM) simulation model of the stone powder–cement particle wet packing system was established based on the dense packing theory. The dense packing behavior of the system was visualized and regulated via the DEM model, leading to an increase in the system's compactness from the original 58.69% to 64.97%. Finally, mechanical property tests and pore structure analysis of the hardened system were conducted to verify, at both macroscopic and mesoscopic scales, the effectiveness of the simulation model in regulating the hardened properties of the stone powder–cement particle packing system. Specifically, after performance regulation, the 28‐day compressive strength of the system increased by 14% compared with the control group, while the porosity decreased by 17.92%. The research findings provide an effective numerical simulation method and theoretical basis for the intelligent design of cement‐based materials based on the dense packing theory.