ISSN: 0149-6123
Page Count: 4

Review of the Thermodynamic Stability of Ettringite
Constantiner, D
Research scientist and senior scientist, Master Builders, Inc., OH

Farrington, SA
Research scientist and senior scientist, Master Builders, Inc., OH

Abstract

A critical review of published solubility and thermodynamic data for ettringite is presented. Today, the data reported in the literature have variability and uncertainty that could affect the outcome of thermodynamic models. One major uncertainty arises from the fact that Ksp^ett and ΔG^frm° for ettringite have been calculated assuming congruent dissolution even when the data indicates incongruent dissolution. Another uncertainty is the effect of the activity of water. This is an issue that exists when dealing with concentrated solutions, and has not been addressed thus far in ettringite thermodynamic studies. Proper modeling requires that the issues presented in this paper be considered to insure reliable results.

Keywords:
ettringite, thermodynamics, modeling, pore solution, stability

Paper ID: CCA10507J
DOI: 10.1520/CCA10507J
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