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Electrically accelerated transport of chlorides in concrete considering non-linear chloride binding in non-equilibrium conditions

  • Przemek Spiesz
  • Jos Brouwers
Conference paper
Part of the RILEM Bookseries book series (RILEM, volume 3)

Abstract

The Rapid Chloride Migration test (NT Build 492) is commonly used in order to determine the chloride diffusion (migration) coefficient in concrete. This coefficient can then be used as the input value for service life design models for concrete structures in marine environment. However, the theoretical background of this test is still raising discussions as the equations describing the transport process of chlorides cannot predict correctly the chloride concentration profiles in concrete.

The new, improved chloride transport model presented in this paper includes the non-linear nature of chloride binding in concrete as well as the non-equilibrium conditions between free- and bound- chloride concentrations, which were not taken into account in the traditional chloride transport model. This new model has been applied to the experimental data and the values of binding parameters, chloride mass transfer coefficient and the effective chloride diffusion coefficient were determined in the optimization process. The derived binding parameters (non-linear Freundlich isotherm) show very good agreement with values obtained from experimental measurements. The chloride mass transfer coefficient reveals a tendency to diminish during the RCM test. The effective diffusion coefficient determined based on the new chloride transport model is in line with the values found in literature.

Keywords

Chloride Concentration Mass Transfer Rate Binding Parameter Chloride Transport Migration Test 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

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    Tang, L. (1996), PhD Thesis, Chalmers University of Technology.Google Scholar
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    Stanish, K. D. (2002), PhD Thesis, University of Toronto.Google Scholar
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    Yuan, Q. (2009), PhD Thesis, University of GhentGoogle Scholar
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    Gruyaert, E., Van den Heede, Ph., De Belie, N. (2009) in Proceedings of the 2 nd International RILEM Workshop on Concrete Durability and Service Life Planning, pp. 440–448.Google Scholar
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    Zibara, H. (2001), PhD Thesis, University of Toronto.Google Scholar

Copyright information

© RILEM 2012

Authors and Affiliations

  1. 1.Eindhoven University of TechnologyEindhovenThe Netherlands

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