水化硅酸钙力学性能分子动力学模拟方法对比研究

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

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。

The mechanical properties of calcium silicate hydrate gel（ C-S-H） are studied. Tobermorite and Jennite crystals are adopted as the initial structure of C-S-H and the unit cells of 3 × 3 × 3 A 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 A 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.