水化硅酸钙力学性能分子动力学模拟方法对比研究

对水化硅酸钙凝胶(C-S-H)的力学性能分子动力学模拟方法进行了对比研究。以Tobermorite和Jennite晶体作为CS-H纳观结构的模型,建立3倍晶胞分别在COMPASS、COMPASS II两种力场下进行分子动力学模拟,得到纳观结构的力学性能。然后根据Powers和Jennings水化模型,引用自融洽(SC)和Mori-Tanka均匀化方法考虑孔隙率因素,计算C-S-H凝胶的力学性能。研究发现,COMPASS力场对C-S-H力学性能的模拟更好;SC方法计算的结果更为接近试验值;Tobermorite 11和Jennite结构模型在力学性能模拟方面更准确;Jennings水化模型与原子模拟研究技术结合较好。

Comparison Study of Methods in Molecular Dynamics Simulation on the Mechanical Properties of Calcium Silicate Hydrate

The mechanical properties of calcium silicate hydrate gel (C-S-H) are studied in this paper. Tobermorite and Jennite crystals are adopted as the initial structure of C-S-H and the unit cells of 3×3×3 are established for molecular dynamics simulation, in which the force fields of COMPASS and COMPASS II were considered. Based on Powers and Jennings model of cement hydration for the definition of C-S-H gel, the methods of Self-Consistent and Mori-Tanka considering the influence of porosity, the mechanical properties of C-S-H gel are calculated. The research reveals that COMPASS is more plausible for modeling the mechanical properties of C-S-H, and the results calculated with SC method show more closeness to the experimental values. As with the structure model, Tobermorite 11? and Jennite perform better in capturing the mechanical properties of C-S-H, and Jennings hydration model can be suitable for being associated with the atomic modeling technology.