21. A reactive transport model based on thermodynamic computations to estimate the atmospheric carbonation of cementitious materials

Title: 21. A reactive transport model based on thermodynamic computations to estimate the atmospheric carbonation of cementitious materials
Author(s): E. Stora, C. Conrardy, R. Barbarulo, J. Chen, F. Thoué
Paper category : conference
Book title: NUCPERF 2009 - Long Term Performance of Cementitious Barriers and Reinforced Concrete in Nuclear Power Plants and Waste Management
Editor(s): V. L'Hostis, R. Gens, C. Gallé
Print-ISBN: 978-2-35158-072-1
e-ISBN: 978-2-35158-087-5
Publisher: RILEM Publications SARL
Publication year: 2009
Pages: 193 - 202
Total Pages: 10
Nb references: 21
Language: English

Abstract: Carbonation of concrete is a process by which carbon dioxide (CO2) in the ambient air penetrates the material and reacts with hydration products, such as portlandite (Ca(OH)2), to form calcite (CaCO3). This phenomenon strongly favours corrosion of reinforced concrete, since the high alkalinity required to protect embedded steel bars decreases in the carbonated area.

Today, cement industries offer cements with very different chemical compositions. This paper deals with the numerical modelling of the carbonation of cementitious materials. The proposed model called DUSS (for DUrability Simulation Software) is implemented in MATLAB to simulate with the finite volume method (in 1D) the transport of CO2 and humidity in cement-based materials. This approach is versatile, since the chemical reactions of hydrates with CO2 are predicted by means of a simplified zonation method based on thermodynamical computations. The model DUSS1.2 presented here is applied to two different cement pastes that have been carbonated under accelerated conditions and characterized at the Lafarge research center.

Online publication: 2009-11-16
Publication type : full_text
Public price (Euros): 0.00