Predicting the atmospheric carbonation of cementitious materials using fully coupled two-phase reactive transport modelling

• Published in: Cement and concrete research Vol. 130; p. 105966
• Main Authors: Seigneur, N., Kangni-Foli, E., Lagneau, V., Dauzères, A., Poyet, S., Bescop, P. Le, L’Hôpital, E., d’Espinose de Lacaillerie, J.-B.
• Format: Journal Article
• Language: English
• Published: Elmsford Elsevier Ltd 01.04.2020; Elsevier BV; Elsevier
• Subjects: Analytical chemistry; Atmospheric carbonation; Atmospheric models; Carbonation; Chemical Sciences; Chemistry and flow coupling; Computer Science; Engineering Sciences; Environment and Society; Environmental Sciences; Fractures; Hytec; Materials; Mathematical models; Modeling and Simulation; Multiphase flow; Numerical Analysis; Parameter sensitivity; Radioactive waste disposal; Reactive fluid environment; Reactive transport modelling; Tricalcium silicate; Variable porosity; Atmospheric carbonation; Multiphase flow; Variable porosity; Chemistry and flow coupling; Hytec; Reactive transport modelling; Variable Porosity; Reactive Transport Modelling
• ISSN: 0008-8846; 1873-3948
• DOI: 10.1016/j.cemconres.2019.105966

The durability assessment of cementitious materials and concrete subjected to atmospheric carbonation of concrete has been an extensive study of research. Experimental studies on the subject show, among other results, that the response depends strongly on the cement composition. This paper focuses on two model materials: an hydrated C3S paste and a low-pH paste, which exhibits a higher tendency to cracking. We show that a fully coupled reactive transport model can reproduce the measured experimental depths of carbonation without a need of fitting parameters. A sensitivity provides insights about the most relevant parameters to accurately model the atmospheric carbonation. Furthermore, results suggest that low-pH cement materials might be inherently less mechanically robust when subjected to atmospheric carbonation, due to a higher C-S-H decalcification rate. This implies that these materials are more likely to develop fractures, which could have implications in the framework of gas or radioactive waste disposal. •Fully coupled reactive transport modelling of atmospheric carbonation of cementitious materials•Good agreement between simulated and experimental degradation depths•Most parameters used in the model are the results of direct measurements.•Results indicate that C-S-H decalcification rates are higher for low-pH materials.