The importance of chloride sensors stability in monitoring ageing phenomena in concrete structures: Ag/AgCl electrodes performance in simulated pore-water environment

The importance of chloride sensors stability in monitoring ageing phenomena in concrete structures: Ag/AgCl electrodes performance in simulated pore-water environment

Pargar, F.
Koleva, D.A.
Koenders, E.A.B.
Van Breugel, K.

Civil Engineering and Geosciences

Structural Engineering

2014-05-28

One of the reported problems associated with the performance of Ag/AgCl electrodes in alkaline environment, as concrete pore water, has been their poor stability. Open circuit potentials are typically observed to be stable for a time period of a few minutes to some days depending on the thickness and microstructure of the sparingly soluble AgCl and the subsequently developed mixed potentials at the electrode/solution interface. In this paper the open circuit potential of the chloride sensors were monitored over time in simulated pore solution with and without chloride and their electrochemical response recorded via electrochemical impedance spectroscopy (EIS). The alterations in response of the sensors can be denoted to transformation of the AgCl layer to Ag2O in chloride-free high pH environment as in concrete pore water. Recovery of the AgCl layer takes place in chloridecontaining medium, where establishing of sensor stability is determined by the chloride concentration.

chloride sensor
open circuit potential
electrochemical impedance spectroscopy

http://resolver.tudelft.nl/uuid:23c5c7aa-fbea-44c7-a0ec-fc91117444d4

DCMat Ageing Centre, Delft University of Technology

978-94-6186-314-0

AMS 14: Proceedings of the 1st Ageing of Materials & Structures Conference, Delft, The Netherlands, 26-28 May 2014

Institutional Repository

conference paper

(c) The authors