Mechanical properties of C-S-H globules and interfaces by molecular dynamics simulation

Research output: Contribution to journalArticle

5 Citations (Scopus)
21 Downloads (Pure)

Abstract

At meso-scale, Calcium Silicate Hydrate (C-S-H) can be considered as randomly packed globules (about 4.2 nm), which forms the basic unit cell, with water molecules and voids. In this paper, the nanostructures for the globules are developed based on some plausible atomic structures of C-S-H. The mechanical properties for the C-S-H globules are determined through molecular dynamics simulation. Interfaces between the C-S-H globules are also simulated with different amount of water molecules. Key material parameters, e.g., Young’s modulus, strength and fracture energy, are obtained. It has been found that longer mean chain length of silicate tends to increase the strength of C-S-H and change the fracture behavior from brittle to ductile failure, in the chain length direction. In the other direction, however, silicate chains do not play an important role while interlayer structure matters. Moreover, pores in the C-S-H nanostructures can considerably reduce the strength of the globule structures in the normal direction to silicate chain but the weakening effect becomes substantially less in silicate chain direction. Further, it has been found that for all types of the interfaces between C-S-H globules, the interface with no extra water molecules has the greatest tensile/shear strength. The mechanical properties obtained in this paper for C-S-H nanostructures and interfaces could be necessary inputs to the meso-scale modelling of C-S-H via either granular mechanics, i.e., DEM, or continuum mechanics, i.e., FEM.
Original languageEnglish
Pages (from-to)573-582
Number of pages10
JournalConstruction and Building Materials
Volume176
Early online date12 May 2018
DOIs
Publication statusPublished - 10 Jul 2018

Fingerprint

Silicic Acid
Calcium silicate
Hydrates
Interfaces (computer)
Molecular dynamics
Silicates
Mechanical properties
Computer simulation
Nanostructures
Chain length
Molecules
Water
Continuum mechanics
Fracture energy
calcium silicate
Shear strength
Mechanics
Elastic moduli
Finite element method
Direction compound

Keywords

  • C-S-H
  • mechanical properties
  • molecular dynamics modeling
  • interfaces
  • colloidal model
  • meso-scale

Cite this

@article{4b41711de411406b8c3bf18af42c1e66,
title = "Mechanical properties of C-S-H globules and interfaces by molecular dynamics simulation",
abstract = "At meso-scale, Calcium Silicate Hydrate (C-S-H) can be considered as randomly packed globules (about 4.2 nm), which forms the basic unit cell, with water molecules and voids. In this paper, the nanostructures for the globules are developed based on some plausible atomic structures of C-S-H. The mechanical properties for the C-S-H globules are determined through molecular dynamics simulation. Interfaces between the C-S-H globules are also simulated with different amount of water molecules. Key material parameters, e.g., Young’s modulus, strength and fracture energy, are obtained. It has been found that longer mean chain length of silicate tends to increase the strength of C-S-H and change the fracture behavior from brittle to ductile failure, in the chain length direction. In the other direction, however, silicate chains do not play an important role while interlayer structure matters. Moreover, pores in the C-S-H nanostructures can considerably reduce the strength of the globule structures in the normal direction to silicate chain but the weakening effect becomes substantially less in silicate chain direction. Further, it has been found that for all types of the interfaces between C-S-H globules, the interface with no extra water molecules has the greatest tensile/shear strength. The mechanical properties obtained in this paper for C-S-H nanostructures and interfaces could be necessary inputs to the meso-scale modelling of C-S-H via either granular mechanics, i.e., DEM, or continuum mechanics, i.e., FEM.",
keywords = "C-S-H, mechanical properties, molecular dynamics modeling, interfaces, colloidal model, meso-scale",
author = "Ding Fan and Shangtong Yang",
year = "2018",
month = "7",
day = "10",
doi = "10.1016/j.conbuildmat.2018.05.085",
language = "English",
volume = "176",
pages = "573--582",
journal = "Construction and Building Materials",
issn = "0950-0618",

}

TY - JOUR

T1 - Mechanical properties of C-S-H globules and interfaces by molecular dynamics simulation

AU - Fan, Ding

AU - Yang, Shangtong

PY - 2018/7/10

Y1 - 2018/7/10

N2 - At meso-scale, Calcium Silicate Hydrate (C-S-H) can be considered as randomly packed globules (about 4.2 nm), which forms the basic unit cell, with water molecules and voids. In this paper, the nanostructures for the globules are developed based on some plausible atomic structures of C-S-H. The mechanical properties for the C-S-H globules are determined through molecular dynamics simulation. Interfaces between the C-S-H globules are also simulated with different amount of water molecules. Key material parameters, e.g., Young’s modulus, strength and fracture energy, are obtained. It has been found that longer mean chain length of silicate tends to increase the strength of C-S-H and change the fracture behavior from brittle to ductile failure, in the chain length direction. In the other direction, however, silicate chains do not play an important role while interlayer structure matters. Moreover, pores in the C-S-H nanostructures can considerably reduce the strength of the globule structures in the normal direction to silicate chain but the weakening effect becomes substantially less in silicate chain direction. Further, it has been found that for all types of the interfaces between C-S-H globules, the interface with no extra water molecules has the greatest tensile/shear strength. The mechanical properties obtained in this paper for C-S-H nanostructures and interfaces could be necessary inputs to the meso-scale modelling of C-S-H via either granular mechanics, i.e., DEM, or continuum mechanics, i.e., FEM.

AB - At meso-scale, Calcium Silicate Hydrate (C-S-H) can be considered as randomly packed globules (about 4.2 nm), which forms the basic unit cell, with water molecules and voids. In this paper, the nanostructures for the globules are developed based on some plausible atomic structures of C-S-H. The mechanical properties for the C-S-H globules are determined through molecular dynamics simulation. Interfaces between the C-S-H globules are also simulated with different amount of water molecules. Key material parameters, e.g., Young’s modulus, strength and fracture energy, are obtained. It has been found that longer mean chain length of silicate tends to increase the strength of C-S-H and change the fracture behavior from brittle to ductile failure, in the chain length direction. In the other direction, however, silicate chains do not play an important role while interlayer structure matters. Moreover, pores in the C-S-H nanostructures can considerably reduce the strength of the globule structures in the normal direction to silicate chain but the weakening effect becomes substantially less in silicate chain direction. Further, it has been found that for all types of the interfaces between C-S-H globules, the interface with no extra water molecules has the greatest tensile/shear strength. The mechanical properties obtained in this paper for C-S-H nanostructures and interfaces could be necessary inputs to the meso-scale modelling of C-S-H via either granular mechanics, i.e., DEM, or continuum mechanics, i.e., FEM.

KW - C-S-H

KW - mechanical properties

KW - molecular dynamics modeling

KW - interfaces

KW - colloidal model

KW - meso-scale

UR - https://www.sciencedirect.com/journal/construction-and-building-materials

U2 - 10.1016/j.conbuildmat.2018.05.085

DO - 10.1016/j.conbuildmat.2018.05.085

M3 - Article

VL - 176

SP - 573

EP - 582

JO - Construction and Building Materials

JF - Construction and Building Materials

SN - 0950-0618

ER -