Mechanical properties of colloidal calcium-silicate-hydrate gel with different gel-pore ionic solutions : A mesoscale study

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Yohannes L. Yaphary
  • Florence Sanchez
  • Denvid Lau
  • Chi Sun Poon

Detail(s)

Original languageEnglish
Article number110944
Journal / PublicationMicroporous and Mesoporous Materials
Volume316
Online published10 Feb 2021
Publication statusPublished - Mar 2021

Abstract

The mechanical properties of hydrated cement paste are largely influenced by the interaction of nano-scale calcium-silicate-hydrate (C–S–H) particles that reside in the gel-pore aqueous ionic solution of colloidal C–S–H gel (C–S-Hgel). The ionic species and ionic concentration of the gel-pore solution can fluctuate – due to the hydration process of cement, the use of various admixtures, and ion exchange with the surrounding environment – and influence the dielectric constant (εr) of the gel-pore solution and the Debye length (κ−1). Mesoscale simulations were employed to investigate the mechanical properties of C–S-Hgel with gel-pore ionic solutions of different εr and κ−1. The results showed that εr and κ−1 influenced the packing density and cohesion of C–S-Hgel, and, in turn, its compressive stiffness, hardness, and strength. The lowest values of εr and κ−1 (i.e., highest ionic concentrations) resulted in higher stiffness, hardness, and strength. The information obtained in this study provided insight into the mechanism by which the gel-pore ionic solution affects the mechanical properties of C–S-Hgel and demonstrated that εr and κ−1 are useful parameters to consider when engineering design strategies for cementitious materials.

Research Area(s)

  • Calcium silicate hydrate (C–S–H), Electrical double layer, Ionic solution, Mechanical properties, Mesoscale simulations

Citation Format(s)