【摘 要】
：
Structure and mechanical properties of Calcium silicate hydrate (C-S-H) at a molecular level act as “DNA” of cement-based construction materials. In order to understand loading resistance capability of C-S-H gel, research on molecular dynamics (MD) was ca
【机 构】
：
School of Civil Engineering, Northeast Forestry University, Harbin 150040, China;School of Materials
【出 处】
：
武汉理工大学学报（材料科学版）（英文版）
论文部分内容阅读
Structure and mechanical properties of Calcium silicate hydrate (C-S-H) at a molecular level act as “DNA” of cement-based construction materials. In order to understand loading resistance capability of C-S-H gel, research on molecular dynamics (MD) was carried out to simulate the uniaxial tension test on C-S-H model along x, y, and z directions. Due to the structure and dynamic differences of the layered structure, the C-S-H model demonstrates heterogeneous mechanical behavior. On an XY plane, the cohesive force can reach 4 GPa, which is mainly provided by the Ca-O and Si-O ionic-covalent bonds. The good plasticity of calcium silicate sheet is attributed to the silicate branch structure formation and the recovery role of interlayer calcium atoms. However, in z direction, C-S-H layers connected by the unstable H-bonds network, have the weakest tensile strength 2.2 GPa. This results in the brittle failure mode in z direction. The relatively low tensile strength and poor plasticity in z direction provides molecular insights into the tensile weakness of cement materials at macro-level.
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