随着城镇化和旧城改造进程的推进，我国建筑废弃物的产生量与堆存量日益增长，废弃黏土砖占建筑废弃物总量的50%~70%。有研究发现：再生砖粉具有作为辅助性胶凝材料的潜力，但会导致水泥基材料的力学性能显著降低。为探究粒径对再生砖粉活性与水泥水化动力学的影响，文中采用高能球磨制备了不同粒径的再生砖粉，表征了再生砖粉的物理化学性质与水化活性，分析了再生砖粉粒径对再生砖粉-硅酸盐水泥体系水化过程、微观结构和力学性能的影响，并基于Krstulovic-Dabic模型获取体系的水化动力学参数，实现水化进程的量化评价。结果表明：随再生砖粉粒径的减小，硅铝矿物晶格畸变的程度变大、表面结合能降低，导致其水化活性提高；水化早期再生砖粉主要起物理填充作用，可加速再生砖粉-硅酸盐水泥体系的早期水化，提高结晶成核与晶体生长→相边界反应→扩散过程转变时的水化程度；随再生砖粉粒径的减小，火山灰反应的开始时间提前且程度增高，最终使掺入30%小粒径再生砖粉水泥的后期强度超过纯水泥的强度，为再生砖粉在水泥基材料中的高效应用奠定基础。

With the advancement of urbanization and the transformation of the old city, the production and stock of construction waste in China are ever increasing, with waste clay bricks accounting for 50%~70%. It has been found that recycled brick powder has the potential as a supplementary cementitious material, but it can lead to a significant reduction in the mechanical properties of cement-based materials. In order to explore the effect of particle size on the activity of recycled brick powder and the hydration kinetics of cement, this study prepared recycled brick powder with different particle sizes by high-energy ball milling. The physical and chemical properties and hydration activity of recycled brick powder were characterized. The effect of particle size of recycled brick powder on the hydration process, microstructure and mechanical properties of recycled brick powder-silicate cement system was analyzed. Based on the Krstulovic-Dabic model, the hydration kinetic parameters of the system were obtained to realize the quantitative evaluation of the hydration process. The results show that with the decrease of the particle size of the recycled brick powder, the lattice distortion of the silicon-aluminum mineral becomes larger and the surface binding energy decreases, resulting in an increase in its hydration activity. The early hydration of recycled brick powder mainly plays a physical filling role, which can accelerate the early hydration of recycled brick powder-cement system and improve the hydration degree of crystallization nucleation and crystal growth→phase boundary reaction→diffusion process. With the decrease of particle size of recycled brick powder, the starting time of pozzolanic reaction is advanced and the degree of pozzolanic reaction is higher. Finally, the later strength of cement mixed with 30% fine-grained recycled brick powder exceeds that of pure cement. This paper lays a foundation for the efficient application of recycled brick powder in cement-based materials.