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Toward the formation mechanism of synthetic calcium silicate hydrate (C-S-H) - pH and kinetic considerations.
- Source :
-
Cement & Concrete Research . Oct2023, Vol. 172, pN.PAG-N.PAG. 1p. - Publication Year :
- 2023
-
Abstract
- The formation of C-S-H in cementitious materials is critical to their gain in strength. As one of the key parameters, pH is reported to affect the nucleation and growth of C-S-H; however, the underlying mechanism remains unclear. In this study, C-S-H was synthesized under different pH conditions, to elucidate the underlying mechanism. Changes in the chemical composition, morphology and structure depending on the reaction time and interactions between pH and C-S-H were tracked using a series of characterizations. Three types of C-S-H (amorphous calcium silicate, C-S-H precursor and semi-crystalline C-S-H) formed at different pH and time points. pH affected the formation of C-S-H mainly through the protonation of silicates, which determined the surface charge of silicate tetrahedra and consequent chemical composition of C-S-H. At high pH, the formation of CaOH+ as the first step before the formation of C-S-H was responsible for the high Ca/Si ratio under such conditions. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00088846
- Volume :
- 172
- Database :
- Academic Search Index
- Journal :
- Cement & Concrete Research
- Publication Type :
- Academic Journal
- Accession number :
- 169704910
- Full Text :
- https://doi.org/10.1016/j.cemconres.2023.107248