MODELING KINETICS OF C-S-H DISSOLUTION DURING CARBONATION OF CEMENT PASTE. BEYOND THE SOLID SOLUTION APPROACH

Author(s): Patrick Dangla, Antoine Morandeau and Mickaël Thiéry
Book Title: RILEM International Symposium on Concrete Modelling - CONMOD 2014
Editor: Kefei Li, Peiyu Yan and Rongwei Yang
ISBN: 978-2-35158-139-1
e-ISBN: 978-2-35158-140-7
Publisher: RILEM Publications SARL
Publication year: 2015
Pages: 400-406
Total Pages: 7
Language: English

Abstract: The thermodynamic of the dissociation reaction of C-S-H is studied by considering the Gibbs free energy of C-S-H as being dependent of the C/S and H/S ratios considered as two independent thermodynamic variables. Firstly equilibrium results in relationships involving the saturation degrees of dissolved pure substances and the C/S ratio of the C-S-H. From this basis the thermodynamic inequality shows that the time rate of change of calcium and silicon contents in C-S-H can be related to the departure from equilibrium in terms of these saturation degrees. Two simple kinetic laws are then proposed. We simulate the carbonation kinetics of a cement sample.

Online publication: 2015
Publication Type: full_text
Public price (Euros): 0.00