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

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

Research output: Journal article publicationJournal articleAcademic researchpeer-review

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.

Original languageEnglish
Article number110944
JournalMicroporous and Mesoporous Materials
Volume316
DOIs
Publication statusPublished - Mar 2021

Keywords

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

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials

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