基于粗粒化分子动力学的自由水与水化硅酸钙孔隙水冻结模拟  

Freezing simulation of free water and water in calcium silicate hydrate based on coarse-grained molecular dynamics

作　　者：张浩 田霞[1] 顾鑫[1] 章青[1] ZHANG Hao;TIAN Xia;GU Xin;ZHANG Qing(College of Mechanics and Materirals,Hohai University,Nanjing 211100,China)

机构地区：[1]河海大学力学与材料学院,南京211100

出　　处：《计算力学学报》2024年第1期194-201,共8页Chinese Journal of Computational Mechanics

基　　金：国家自然科学基金(11932006,12172121);高铁联合基金(U1934206)资助项目.

摘　　要：水化硅酸钙是水泥基材料的主要水化产物,其孔隙内的水分是影响水泥基材料抗冻性的主要因素。本文基于粗粒化分子动力学方法研究水化硅酸钙孔隙水的冻结机制,针对水的粗粒化P_(4)粒子和水化硅酸钙胶体颗粒,建立了水化硅酸钙孔隙水的冻结模型。根据此模型计算了不同孔径孔隙水冰点,分析了水泥基材料孔径孔隙在冻融破坏中的危害程度;模拟得到了水化硅酸钙孔隙内水的冻结分布特征和密度分布特征。研究工作表明,本文建立的模型有效提高了分子动力学模拟水化硅酸钙孔隙水冻结问题的规模,为后续进行水泥基材料的冻融破坏分析提供了研究基础。Calcium silicate hydrate is the main hydration product of cement-based materials,and the water in its pores is the main factor affecting the frost resistance of cement-based materials.This paper studies the freezing mechanism of calcium silicate hydrate pore water based on the coarse-grained molecular dynamics method.A freezing model of calcium silicate hydrate pore water is established for the coarse-grained P_(4)particles and calcium silicate hydrate colloidal particles of water.Based on this model,the freezing point of pore water with different pore diameters is calculated,and the damage degree of pore water in cement-based materials during freeze thaw is analyzed;The freezing distribution characteristics and density distribution characteristics of water in the pores of calcium silicate hydrate are determined.The research work shows that the model established in this paper effectively improves the scale of molecular dynamics simulation of calcium silicate hydrate pore water freezing problems,provides a model basis for subsequent cement pore water freezing simulation,and creates a scientific basis for revealing the freeze-thaw failure mechanism of cement-based materials.

关 键 词：水化硅酸钙 相变特性 粗粒化 分子动力学 冰点 

分 类 号：O313[理学—一般力学与力学基础] O302[理学—力学]