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Evaluation of Ag/AgCI sensors for in-situ monitoring of freee chloride concentration in reinforced concrete structures

Pargar, F. ; Koleva, D. A. ; Copuroglu, O. ; Koenders, E. A. B. ; Breugel, K. van (2014)
Evaluation of Ag/AgCI sensors for in-situ monitoring of freee chloride concentration in reinforced concrete structures.
Young Researchers’ Forum II: Construction Materials. London, UK (19th February 2014)
Konferenzveröffentlichung, Bibliographie

Kurzbeschreibung (Abstract)

The level of free chloride concentration in reinforced concrete structures essentially determines the onset of steel corrosion initiation and further propagation. One of the well-known methods for monitoring free chloride concentration is using silver/silver chloride electrodes (Ag/AgCl). These electrodes are sensitive mainly to chloride ions and establish a certain electrochemical potential depending on the chloride ion activity in the environment. Although the functioning principles of these electrodes are well-established, their use in concrete is challenging when durability and practical engineering issues are considered. In order to be able to accurately determine free chloride content in concrete, it is important to evaluate the performance of Ag/AgCl electrodes (sensors) in strong alkaline environments i.e. those existing in non-carbonated concrete (pH~12–13.5). Furthermore the linear response of these sensors to a wide range of chloride concentrations in highly alkaline medium, as well as their sensitivity to pH changes, need a more in-depth investigation. In this paper the response of Ag/AgCl electrodes in simulated pore solutions having different chloride concentrations and different pH values was studied. The electrodes were calibrated in cement extract solution, distilled-water and simulated pore solution. The results show that at chloride concentrations of \textgreater 4 mM the effect of pH on the response of the sensors is insignificant which makes using Ag/AgCl sensors in concrete feasible i.e. this concentration is much lower than the generally reported thresholds for corrosion initiation. Keywords: Ag/AgCl electrode, cement extract solution, free chloride, pH value, pore solution.

Typ des Eintrags: Konferenzveröffentlichung
Erschienen: 2014
Autor(en): Pargar, F. ; Koleva, D. A. ; Copuroglu, O. ; Koenders, E. A. B. ; Breugel, K. van
Art des Eintrags: Bibliographie
Titel: Evaluation of Ag/AgCI sensors for in-situ monitoring of freee chloride concentration in reinforced concrete structures
Sprache: Englisch
Publikationsjahr: Februar 2014
Verlag: University College London
Veranstaltungstitel: Young Researchers’ Forum II: Construction Materials
Veranstaltungsort: London, UK
Veranstaltungsdatum: 19th February 2014
URL / URN: http://resolver.tudelft.nl/uuid:95faa6e6-bfa9-4f7b-8e25-de4a...
Kurzbeschreibung (Abstract):

The level of free chloride concentration in reinforced concrete structures essentially determines the onset of steel corrosion initiation and further propagation. One of the well-known methods for monitoring free chloride concentration is using silver/silver chloride electrodes (Ag/AgCl). These electrodes are sensitive mainly to chloride ions and establish a certain electrochemical potential depending on the chloride ion activity in the environment. Although the functioning principles of these electrodes are well-established, their use in concrete is challenging when durability and practical engineering issues are considered. In order to be able to accurately determine free chloride content in concrete, it is important to evaluate the performance of Ag/AgCl electrodes (sensors) in strong alkaline environments i.e. those existing in non-carbonated concrete (pH~12–13.5). Furthermore the linear response of these sensors to a wide range of chloride concentrations in highly alkaline medium, as well as their sensitivity to pH changes, need a more in-depth investigation. In this paper the response of Ag/AgCl electrodes in simulated pore solutions having different chloride concentrations and different pH values was studied. The electrodes were calibrated in cement extract solution, distilled-water and simulated pore solution. The results show that at chloride concentrations of \textgreater 4 mM the effect of pH on the response of the sensors is insignificant which makes using Ag/AgCl sensors in concrete feasible i.e. this concentration is much lower than the generally reported thresholds for corrosion initiation. Keywords: Ag/AgCl electrode, cement extract solution, free chloride, pH value, pore solution.

Fachbereich(e)/-gebiet(e): 13 Fachbereich Bau- und Umweltingenieurwissenschaften
13 Fachbereich Bau- und Umweltingenieurwissenschaften > Institut für Werkstoffe im Bauwesen
Hinterlegungsdatum: 04 Jun 2015 08:42
Letzte Änderung: 14 Jan 2019 14:49
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