Abstract
Chlorides induce local corrosion in the steel reinforcements when reaching the bar surface. The measurement of the rate of ingress of these ions, is made by mathematically fitting the so called “error function equation” into the chloride concentration profile, obtaining so the diffusion coefficient and the chloride concentration at the concrete surface. However, the chloride profiles do not always follow Fick’s law by having the maximum concentration at the concrete surface, but often the profile shows a maximum concentration more in the interior, which indicates a different composition and performance of the most external concrete layer with respect to the internal zones. The paper presents a procedure prepared during the time of the RILEM TC 178-TMC: “Testing and modeling chloride penetration in concrete”, which suggests neglecting the external layer where the chloride concentration increases and using the maximum as an “apparent” surface concentration, called C max and to fit the error function equation into the decreasing concentration profile towards the interior. The prediction of evolution should be made also from the maximum.
Similar content being viewed by others
References
Crank J (1986) The mathematics of diffusion, 2nd edn. Clarendon Press, Oxford
Andrade C, Díez JM, Alonso C (1997) Mathematical modeling of a concrete surface “skin effect” on diffusion in chloride contaminated media. Adv Cem Based Mater 6:39–44
Bamforth PB, Price WF, Emerson M (1997) An international review of chloride ingress into structural concrete. Transport Research Laboratory, Taywood Engineering Ltd., Contractor Report 359, pp. 95–114
Castellote M, Andrade C (2002) Analysis of water soluble chloride content in concrete. RILEM Recommendation of TC-178-”Testing and modeling chloride penetration in concrete”. Mater Struct 35:586–588
Castellote M, Andrade C (2002) Analysis of total chloride content in concrete. RILEM Recommendation of TC-178-”Testing and modeling chloride penetration in concrete”. Mater Struct 35:583–585
Castellote M, Andrade C (2006) Round-robin test on methods for determining chloride transport in concrete. RILEM recommendation of TC-178-”Testing and modeling chloride penetration in concrete”. Mater Struct 30:990–995
Vennesland Ø, Climent MA, Andrade C (2013) Methods for obtaining dust samples by means of grinding concrete in order to determine the chloride concentration profile. Mater Struct 46:337–344
Andrade C, Guidance for the evaluation of models of chloride penetration into concrete (submitted to publication in M&S)
Vennesland Ø, Andrade C, Climent MA, Gulikers J, Polder R, Method for field determination of critical chloride content (threshold value) for depassivation of steel (submitted to publication in M&S)
Andrade C, Tavares F, Petre-Lazar I, Climent MA, de Vera G, Benchmarking of chloride diffusion models (submitted to publication in M&S)
Acknowledgments
The authors are grateful to the RILEM TC-178 members for the fruitful discussions, in particular to: V. Baroghel-Bouny, M. Carcasses, M. Castellote, Th. Chaussadent, J. Gulikers, J. Kropp, M. Maultzsch, S. Meijers, C. Page, I. Petre-Lazars, R. Polder, A. Raharinaivo, M. Salta, M. Thomas, J. Tritthart, O. Troconis de Rincon, Ø. Vennesland.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Andrade, C., Climent, M.A. & de Vera, G. Procedure for calculating the chloride diffusion coefficient and surface concentration from a profile having a maximum beyond the concrete surface. Mater Struct 48, 863–869 (2015). https://doi.org/10.1617/s11527-015-0543-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1617/s11527-015-0543-4