Modelling of reinforcement corrosion – Influence of concrete technology on corrosion development

Self Cite

Although the complex changes at the steel-concrete interface due to cathodic polarisation are widely acknowledged to have a beneficial influence concerning the cathodic protection (CP) of steel in concrete, some questions concerning the repassivation of carbon steel in consequence of cathodic polarisation are still not satisfactorily clarified. In the recent literature, some indications are presented that repassivation occurs after a certain time of polarisation. Therefore, the investigations discussed in this paper aim to clarify, to what extent the re-passivation of carbon steel due to cathodic polarisation occurs, and if the ennoblement of OCP is a sufficient indication for repassivation. In a first step, the corrosion state of five nominal equal test specimens was determined by electrochemical impedance spectroscopy (EIS). After determining the initial corrosion state by evaluating the charge transfer resistance and the polarisation resistance, respectively, the specimens were polarised cathodically. Impedance data were recorded before, during and after polarisation. The impedance data were evaluated by equivalent circuit fitting with special attention to charge transfer resistances and the impact of diffusion on the corrosion and polarisation behaviour. The results indicate that the reduction of oxides and oxygen diffusion during cathodic polarisation has strong impact on the systems behaviour and that repassivation effects occur after switching off the polarisation current and during depolarisation, respectively.

Section: Instrumentation and Test Setup 21 Specimen Design And Test mentioning

confidence: 99%

Investigations on the re‐passivation of carbon steel in chloride containing concrete in consequence of cathodic polarisation

Eichler

Isecke

Bäßler

2009

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“…In contrary to the samples (Fig. 1) in a research project [4] in pre-tests to estimate the possibilities for the examination with X-ray tomography a simplified experimental arrangement was used (Fig. 2).…”

Section: Corrosion Conceptsmentioning

confidence: 99%

“…Until now it is impossible to collect such information without destroying probes after electrochemical testing has taken place. Within the scope of a research project [3] the part of self-corrosion of the total corrosion was analysed [4]. For this purpose different types of specimens were developed, concrete cubes and concrete cylinders.…”

Section: Introductionmentioning

confidence: 99%

Application of X‐ray tomography for the verification of corrosion processes in chloride contaminated mortar

Beck¹,

Goebbels²,

Bürkert³

2007

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“…A chloride content of 1% with respect to the cement mass was chosen according to a research program (DFG-research group 537) that currently is carried out at the Federal Institute of Materials Research and Testing, (BAM Berlin) to investigate the influence of micro cell corrosion on chlorideinduced macro cell corrosion [14,15]. In addition, a chloride www.wiley-vch.de/home/wuk content of 1.0%Cl À with respect to the cement mass (1.0 M%Cl À /cem) should be in ranges of critical corrosion-inducing chloride contents for steel in concrete [13].…”

Section: Instrumentation and Test Setupmentioning

confidence: 99%

Electrochemical noise measurements on unalloyed steel in chloride‐containing alkaline environment

Eichler

Bürkert

Beck

2007

Self Cite

The investigations discussed in this paper aim to clarify whether electrochemical noise measurements (ENM) are capable for application in concrete and mortar, particularly with regard to pitting initiation in such environment. For these purposes, the results of several different test series are compared and discussed. Based on investigations on passivity and pitting corrosion in alkaline solutions with different chloride contents further results in cement paste, mortar and concrete are evaluated.