Electrochemical techniques for evaluation of protective coatings against corrosion in concrete structures
Adriana de Araujo; Zehbour Panossian
Electrochemical techniques are one of the main tools for studying corrosion in civil engineering. They can be used to evaluate for example the performance of concrete components, ratios and also protective coatings. In this paper, some electrochemical measurements are discussed and an appropriate specimen configuration is proposed to the evaluation of concrete protection coatings by electrochemical techniques using a potenciostat. This configuration is conceived in order to permit the accomplishment of electrochemical measurement during accelerated corrosion tests without causing damages to the applied coating due to the humidification of the concrete specimen and/or the electrical connections of the electrodes. For such, accelerated corrosion tests were conducted with the support of FAPESP, in two different environments: one contaminated with chloride and the other with carbon dioxide. It was verified that the proposed specimen is adequate for concrete protection coating evaluation, and that the corrosion potential was the most appropriate electrochemical parameter for both aggressive environments, but the corrosion rate was appropriate only for the carbon dioxide contaminated environment.
ARAUJO.A. de; PANOSSIAN, Z.Técnicas Eletroquimicas para Avaliação de pinturas de proteção contra corrosão nas estruturas de concreto. In: BRAZILIAN CORROSION CONGRESS, 26., IBERO AMERICAN CONGRESS OF CORROSION AND PROTECTION, 9., NACE LATIN-AMERICAN REGION CORROSION CONGRESS, 6.; PHOTOGRAPHY CONTEST CORROSION AND MATERIAL DEGRADATION, 13., INDUSTRIAL TECHNICAL EXPOSITION, 26.; CONGRESSO LATINO AMERICANO DE CORROSÃO, LATINCORR, 6., 2006, Salvador. Proceedings... (CD ROM))
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