0
research-article

Constitutive Stiffness Characteristics of Cement Paste as a Multi-Phase Composite System - A Molecular Dynamics Based Model

[+] Author and Article Information
Ingrid Padilla Espinosa

Nanoengineering Department, Joint School of Nanoscience and Nanoengineering North Carolina A&T State University 2907 E Gate City Blvd, Greensboro, NC 27401
impadill@aggies.ncat.edu

Wayne Hodo

Engineering Research and Development Center 3909 Halls Ferry Road, Vicksburg, MS 39180
Wayne.d.hodo@usace.army.mil

John S. Rivas Murillo

Nanoengineering Department, Joint School of Nanoscience and Nanoengineering North Carolina A&T State University 2907 E Gate City Blvd, Greensboro, NC 27401
jrmurill@ncat.edu

Arunachalam M. Rajendran

Department of Mechanical Engineering University of Mississippi, Oxford, MS 38677
raj@olemiss.edu

Ram Mohan

Nanoengineering Department, Joint School of Nanoscience and Nanoengineering North Carolina A&T State University 2907 E Gate City Blvd, Greensboro, NC 27401
rvmohan@ncat.edu

1Corresponding author.

ASME doi:10.1115/1.4036588 History: Received October 03, 2016; Revised March 30, 2017

Abstract

Cement paste is a material with heterogeneous composite structure consisting of hydrated and unhydrated phases at all length scales that varies depending upon the degree of hydration. In this paper, a method to model cement paste as a multi-phase system at molecular level for predicting constitutive properties and for understanding the constitutive mechanical behavior characteristics using molecular dynamics is presented. The proposed method creates a framework for molecular level models suitable for predicting constitutive properties of heterogeneous cement paste that could provide potential for comparisons with low length scale experimental characterization techniques. The molecular modeling method followed two approaches, one involving admixed molecular phases, and the second involving clusters of the individual phases. In particular, in the present study, cement paste is represented as two-phase composite systems consisting of the calcium silicate hydrate (CSH) phase combined with unhydrated phases tricalcium silicate (C3S) or dicalcium silicate (C2S). Predicted elastic stiffness constants based on molecular model representations employed for the two phases showed that, although the individual phases have anisotropic characteristics, the composite system behaves as an isotropic material. The isotropic characteristics seen from two-phase molecular models mimic the isotropic material nature of heterogeneous cement paste at engineering scale. Further, predicted bulk modulus of the composite system based on molecular modeling is found to be high compared to the elastic modulus, which concurs with the high compression strength of cement paste seen at engineering length scales.

Copyright (c) 2017 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In