An engineering approach to the problem of natural carbonation accompanied by drying-wetting cycles

Title: An engineering approach to the problem of natural carbonation accompanied by drying-wetting cycles
Author(s): M. Thiery, V. Baroghel-Bouny, C. Crémona
Paper category : conference
Book title: International RILEM Symposium on Concrete Modelling - ConMod '08
Editor(s): E. Schlangen and G. De Schutter
Print-ISBN: 978-2-35158-060-8
e-ISBN: 978-2-35158-076-9
Publisher: RILEM Publications SARL
Publication year: 2008
Pages: 265 - 273
Total Pages: 9
Nb references: 11
Language: English

Abstract: Drying-wetting cycles have a dominating influence on the carbonation process of reinforced concrete structures, since the diffusion coefficient of carbon dioxide (CO2) in the concrete thickness and the reaction rate of the CO2 dissolution in the pores strongly depend on the moisture content. The Papadakis’ (1989) [1] and Bakker’s (1993) [2] models are engineering approaches to the problem of carbonation in cementitious materials. The Papadakis’ model predicts the formation of a sharp carbonation front which evolves as a square root of time law. The Bakker’s model improves the Papadakis’ approach by taking into account the influence of wetting and drying cycles. The Bakker’s model was certainly the first to tackle this delicate issue. It is based on the assumption that the carbonation progress is negligible as long as the concrete is wet. In the present paper, the Bakker’s approach is supplemented thanks to new advances, both in the fields of carbonation and moisture transport modelling in cementitious materials. In a second stage, a sensitivity analysis is performed for these models in order to identify and quantify the most sensitive variables to be considered as probabilistic ones while some others can be treated as deterministic. In a third stage, a reliability analysis is carried out, as an illustration, to assess the residual service life of a 16-year old reinforced concrete structure. Finally, this study focuses on the use of field data (e.g. a depth of carbonation at a given time) for updating the reliability analysis according to a Bayesian approach.

Online publication: 2009-06-15
Publication type : full_text
Public price (Euros): 0.00

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