Efficiency control of cathodic protection measured using passivation verification technique in different concrete structures
article
It is well known that cathodic protection is the most useful method for stopping corrosion when the deterioration process has started, but the most important issue that is still missing in the cathodic protection studies is how to check its efficiency in a reliable way. This paper presents results of the protection efficiency obtained in different cathodic-protected structures. This efficiency has been measured by traditional methods, which check the proper function of the cathodic protection by switching off the current and either measuring the polarized potential or by recording the evolution of the potential decay. These methods, although based on much experience, do not provide information directly about the state of the metal, and interpretation of the results is not always evident. On the other hand, a new electrochemical technique called passivation verification technique (PVT) have been used for the cathodic protection efficiency measurements. This technique is based on the impedance spectroscopy analysis in a certain range of frequencies. Its main advantage is that it is able to detect the galvanic couple activity of a cathodic protection system, and in this way detects its efficiency faster than standard methods and do not require interruption of the cathodic protection current. For the accomplishment of the tests, different specimens and real structures were measured in Holland and Norway. The results seem very promising and indicate the good operation of the PVT isolated or combined with the traditional methods in the majority of the studied systems. © 2007, NACE International.
Topics
Cathodic protectionConcrete structuresOn-site evaluationPassivation verification techniqueConcretesElectric breakdownPassivationCathodic protection systemsConcrete structuresDeterioration processesEfficiency controlsElectrochemical techniquesGalvanic couplesImpedance spectroscopiesMeasuringOn-site evaluationPolarized potentialsPotential decaysProtection efficienciesReal structuresReliableStandard methodsStill missingSwitching offsVerification techniquesCathodic protection
TNO Identifier
280083
ISSN
00109312
Source
Corrosion, 63(9), pp. 880-892.
Pages
880-892
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