摘   要：在水泥水化进程中，硅酸三钙（C₃S）的水化行为对水泥基材料性能的发展至关重要，但其表面缺陷对水化过程的影响机理尚不明确。鉴于此，本文基于第一性原理研究了C₃S表面点缺陷对其与水分子的相互作用及水化过程的影响。结果表明：C₃S表面钙缺陷降低了局部结构密度，增强了水分子在缺陷位点的吸附能，并促进了水分子的解离、吸附；钙缺陷导致表面电荷分布不均，增强了吸附过程中的电荷转移；缺陷位点的轨道杂化程度提高，进一步调控了吸附过程中的键合性质；由于钙缺陷的形成，水分子与C₃S表面的氢键相互作用增强，有助于加快水泥的初期水化反应，提高水泥基材料的早期强度和耐久性能。研究成果为理解C₃S微观缺陷对宏观性能的影响提供理论依据，并为通过调控点缺陷优化水泥基材料的性能提供参考。

Abstract: During the cement hydration process, the hydration behavior of tricalcium silicate (C₃S) is critical to the property evolution of cement-based materials. Nevertheless, the mechanism underlying the effects of its surface defects on the hydration process remains unclear. In view of this, the first-principles calculations were performed in this work to investigate the influence of point defects on the C₃S surface on its interaction with water molecules and the hydration process. The results show that calcium defects on the C₃S surface reduce the local structural density, increase the adsorption energy of water molecules at defect sites, and promote the dissociation and adsorption of water molecules. Calcium defects lead to inhomogeneous surface charge distribution and enhance charge transfer during adsorption. The degree of orbital hybridization at defect sites is elevated, which further modulates the bonding characteristics during adsorption. Owing to the formation of calcium defects, the hydrogen-bond interaction between water molecules and the C₃S surface is strengthened, which helps accelerate the early hydration of cement and improve the early strength and durability of cement-based materials. The findings provide a theoretical basis for understanding the influence of microscopic defects in C₃S on macroscopic properties and offer a reference for optimizing the performance of cement-based materials by regulating point defects.