Thermodynamic modeling of phase changes in neutralization reaction using PHREEQC

Author(s): Y. Hosokawa, K. Yamada, B. Johannesson, L.O. Nilsson
Paper category: Workshop
Book title: International RILEM Workshop on Performance Based Evaluation and Indicators for Concrete Durability
Editor(s): V. Baroghel-Bouny, C. Andrade, R. Torrent, K. Scrivener
ISBN: 978-2-912143-95-2
Pages: 127 - 133
Total Pages: 7
Language: English

Abstract: 
In the simulation technique of evaluating the ionic mass transfer for the durability assessment of RC structures, the development of models for chemical reactions, such as binding of chloride ions, has recently become a significant issue. In this study, thermodynamic modeling was investigated to simulate the changes of hydrate phases caused by neutralization using PHREEQC - a computer program for aqueous geochemical calculations. The model has been applied successfully to describe the dissolution/precipitation behavior of calcium aluminate phases, especially the decomposition of Friedel's salt, and releasing chloride ion into pore solution. For the behavior of C-S-H gel, utilizing the proposed model assuming a binary non-ideal solid solution of Ca(OH)₂ and SiO₂, a continued reduction of CaO/SiO₂ can be reproduced. Accordingly, this model has allowed appropriate evaluation of chemical reactions of cementitious materials under any type of deterioration.

Online publication: 2007
Publication Type: full_text
Public price (Euros): 0.00