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Coupling between chemical degradation and mechanical behaviour of leached concrete; Couplage degradation chimique - comportement en compression du beton

Abstract

This work is in the context of the long term behavior of concrete employed in radioactive waste disposal. The objective is to study the coupled chemo-mechanical modelling of concrete. In the first part of this contribution, experimental investigations are described where the effects of the calcium leaching process of concrete on its mechanical properties are highlighted. An accelerated method has been chosen to perform this leaching process by using an ammonium nitrate solution. In the second part, we present a coupled phenomenological chemo-mechanical model that represents the degradation of concrete materials. On one hand, the chemical behavior is described by the simplified calcium leaching approach of cement paste and mortar. Then a homogenization approach using the asymptotic development is presented to take into account the influence of the presence of aggregates in concrete. And on the other hand, the mechanical part of the modelling is given. Here continuum damage mechanics is used to describe the mechanical degradation of concrete. The growth of inelastic strains observed during the mechanical tests is describes by means of a plastic like model. The model is established on the basis of the thermodynamics of irreversible processes framework. The coupled nonlinear problem at hand is addressed  More>>
Authors:
Publication Date:
Oct 15, 2005
Product Type:
Thesis/Dissertation
Report Number:
FRNC-TH-6614
Resource Relation:
Other Information: TH: These structures et materiaux; Also available from ENPC-Service documentaire, 6-8 Avenue Blaise Pascal Cite Descartes - Champs-sur-Marne, 77455 - Marne-la-Vallee Cedex 2 (France)
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; COMPUTERIZED SIMULATION; CONCRETES; FINITE ELEMENT METHOD; LEACHING; MORPHOLOGY; PLASTICITY; RADIOACTIVE WASTE DISPOSAL; RESEARCH PROGRAMS
OSTI ID:
21000770
Research Organizations:
Ecole Nationale des Ponts et Chaussees (ENPC), 77 - Marne-la-Vallee (France)
Country of Origin:
France
Language:
French
Other Identifying Numbers:
TRN: FR0605196025636
Availability:
Available from INIS in electronic form
Submitting Site:
FRN
Size:
219 pages
Announcement Date:
Apr 14, 2008

Citation Formats

Nguyen, V H. Coupling between chemical degradation and mechanical behaviour of leached concrete; Couplage degradation chimique - comportement en compression du beton. France: N. p., 2005. Web.
Nguyen, V H. Coupling between chemical degradation and mechanical behaviour of leached concrete; Couplage degradation chimique - comportement en compression du beton. France.
Nguyen, V H. 2005. "Coupling between chemical degradation and mechanical behaviour of leached concrete; Couplage degradation chimique - comportement en compression du beton." France.
@misc{etde_21000770,
title = {Coupling between chemical degradation and mechanical behaviour of leached concrete; Couplage degradation chimique - comportement en compression du beton}
author = {Nguyen, V H}
abstractNote = {This work is in the context of the long term behavior of concrete employed in radioactive waste disposal. The objective is to study the coupled chemo-mechanical modelling of concrete. In the first part of this contribution, experimental investigations are described where the effects of the calcium leaching process of concrete on its mechanical properties are highlighted. An accelerated method has been chosen to perform this leaching process by using an ammonium nitrate solution. In the second part, we present a coupled phenomenological chemo-mechanical model that represents the degradation of concrete materials. On one hand, the chemical behavior is described by the simplified calcium leaching approach of cement paste and mortar. Then a homogenization approach using the asymptotic development is presented to take into account the influence of the presence of aggregates in concrete. And on the other hand, the mechanical part of the modelling is given. Here continuum damage mechanics is used to describe the mechanical degradation of concrete. The growth of inelastic strains observed during the mechanical tests is describes by means of a plastic like model. The model is established on the basis of the thermodynamics of irreversible processes framework. The coupled nonlinear problem at hand is addressed within the context of the finite element method. Finally, numerical simulations are compared with the experimental results for validation. (author)}
place = {France}
year = {2005}
month = {Oct}
}