Adaptation of the galvanodynamic electrochemical technique to the study of steel corrosion immersed in concrete

Author(s): M. V. V. Almeida de Sá, H. S. Júnior, A. C. Vieira da Nóbrega, D. R. da Silva
Paper category: Workshop
Book title: International RILEM Workshop on Integral Service Life Modelling of Concrete Structures
Editor(s): R.M. Ferreira, J. Gulikers, C. Andrade
Print ISBN: 978-2-35158-058-5
e-ISBN: 978-2-35158-090-5
Publisher: RILEM Publications SARL
Pages: 403 - 410
Total Pages: 8
Language: English

Electrochemical techniques, to evaluate the corrosion of the steel immersed in concrete structures, has been the study focus of many researchers. This work has proposed to substitute the potentiodynamic method widely used on polarization curves for the galvanodynamic one, adaptating it to the concrete/steel system. The galvanodynamic method’s advantage is being able to obtain the electrochemical parameters near the electrical double layer. Thus, even using a current near to zero the circuit will work in a potential near to the equilibrium potential. It proposes an electrical circuit analogy to a steel electrode immersed in concrete constituted of two resistances: R1 represents the electrical resistance to the current passing due to the concrete and R2 corresponds to the difficult of the load transfer between the concrete and the electrode. This electrical circuit is still composed of a parallel, which corresponds to the electrical double layer. In the analogy circuit it is possible to separate the two resistances R1 and R2, the capacitance C and the electrical charge q. Applying curves adjusting non-linear mathematic methods, given the initial parameter values, it is possible to approximate the theoretical and the experimental curves and therefore find the values R1, R2, C and q.

Keywords: concrete, corrosion, electrochemical measurements, galvanodynamic technique, electrical circuit.

Online publication: 2013
Publication Type: full_text
Public price (Euros): 0.00

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