Articles
  • Molecular dynamics study on mechanical properties of C-S-H composites

  • Xianfeng Wanga, Peng Weia, Rui Hana, Wei Xiea, Taoran Lia, Dawang Lia,*, Yong Ganb, Zhen Chenc,* and Feng Xinga

  • aGuangdong Provincial Key Laboratory of Durability for Marine Civil Engineering; College of Civil Engineering, Shenzhen University, Shenzhen, P.R. China
    bSchool of Aeronautics and Astronautics, Zhejiang University, Hangzhou, Zhejiang 310027, P.R. China
    cDepartment of Civil and Environmental Engineering, University of Missouri, Columbia, MO 65211, USA

Abstract

In this paper, the mechanical properties of calcium silicate hydrate gel (C-S-H) are investigated with molecular dynamics (MD) simulations, in which the Tobermorite 9Å, Tobermorite 11Å, Tobermorite 14Å and Jennite crystals are treated as fundamental models of the C-S-H nanostructure. The initial structures of the crystal models are firstly preprocessed and optimized, and then are simulated in the canonical (NVT) ensemble conditions. The orthotropic elastic constants of the C-S-H nanostructure are determined and used to derive the bulk and shear moduli via the Voigt-Reuss-Hill method. The self-consistent, Mori-Tanaka, and Voigt methods are employed to compute the mechanical properties of various mixtures of C-S-H composites with different porosities. The simulated results are found to be in a reasonable agreement with those obtained from nano-indentation tests, while the result obtained from the Mori-Tanaka method appears to be the closest to the experimental one. It could also be observed that the mechanical properties of C-S-H vary within a certain range as the porosity and proportions of the components change.


Keywords: C-S-H, Molecular Dynamics, Composite, Mechanical Properties, Porosity

This Article

  • 2019; 20(S1): 19-30

    Published on Jul 20, 2019

  • Received on Dec 9, 2018
  • Revised on Jan 11, 2019
  • Accepted on Jan 11, 2019

Correspondence to

  • Dawang Li a,*, Zhen Chen c,*

  • aGuangdong Provincial Key Laboratory of Durability for Marine Civil Engineering; College of Civil Engineering, Shenzhen University, Shenzhen, P.R. China
    cDepartment of Civil and Environmental Engineering, University of Missouri, Columbia, MO 65211, USA
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  • E-mail: lidw@szu.edu.cn, chenzh@missouri.edu