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Bertolini, Luca; Bolzoni, F.; Pedeferri, Pietro; Lazzari, Luciano; Pastore, Tommaso

doi:10.1023/a:1003404428827

Cited by 116 publications

(42 citation statements)

References 3 publications

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“…When CP is applied to reinforcing steel in concrete however, the objective might not always be to achieve ''immunity'' but to reduce the risk of chloride-induced corrosion, by polarizing the steel from its condition of chloride-induced corrosion (or ''pitting'') to the domain of ''imperfect passivity,'' where pitting is unstable [6,7,13]. In case CP is initially applied within the construction of a structure, i.e., before exposure to aggressive environments, then only a modest polarization of the steel surface will be sufficient for corrosion protection, the technique being applied and denoted as ''cathodic prevention'' [6,14,15].…”

Section: Technical Backgroundmentioning

confidence: 99%

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Conventional and pulse cathodic protection of reinforced concrete: Electrochemical behavior of the steel reinforcement after corrosion and protection

Koleva¹,

Guo²,

Breugel³

et al. 2009

Materials & Corrosion

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The applicability and efficiency of an alternative for impressed current cathodic protection (CP) for reinforced concrete, based on pulse technology, was investigated. The technique, denoted as pulse CP (pCP), was evaluated on the basis of a comparative analysis to reference (non-corroding), corroding, and conventional CP conditions, in terms of long-term monitoring of electrochemical parameters for the embedded steel with time of corrosion and protection. The hereby reported results are for the total duration of the experiment, i.e., 460 days of conditioning, also presented in comparison with earlier stages. Protection was applied after corrosion was initiated (using corrosion medium of 5% NaCl), at different time intervals (here reported are starting points 60 and 150 days of age). Both CP regimes used current density of 5 or 20 mA/m 2 steel surface. The pulse CP was applied as a pulse-shaped block current (square wave) with the current itself being the feedback control signal, using 12.5-50% duty cycle at 500 Hz to 1 kHz frequency. Under equal environmental conditions and for a comparatively long period of application, the pulse CP was found to perform as effectively as the conventional CP with regard to electrochemical behavior of the steel reinforcement. Furthermore, the pulse CP technique was found to achieve more rapidly the so called ''open circuit potential (OCP) passivity'' as a result of an enhanced ion transport (chloride withdrawal) and more favorable cement chemistry (increased alkalinity around the steel reinforcement).

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Section: Technical Backgroundmentioning

confidence: 99%

“…[24]. Therefore, a protection regime which uses lower current density (i.e., lower than the usually recommended range of 5-20 mA/m 2 for structures exposed to the atmosphere [15]) is expected to minimize the side effects.…”

Section: Technical Backgroundmentioning

confidence: 99%

Conventional and pulse cathodic protection of reinforced concrete: Electrochemical behavior of the steel reinforcement after corrosion and protection

Koleva¹,

Guo²,

Breugel³

et al. 2009

Materials & Corrosion

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“…It corresponds to "restoring the passivity" of steel in chloride contaminated concrete. Bertolini et al [16] already stated that it is not necessary to reach such a potential to reduce the macrocouple activity on its surface. But the results presented in this paper make a supplementary step indicating that a criterion expressed in terms of potential value is a not suitable for reinforced concrete structures under ICCP, because of the nonuniformity of potential field.…”

Section: Discussion -Conclusionmentioning

confidence: 99%

Cathodic protection in reinforced concrete structures affected by macrocell corrosion: a discussion about the significance of the protection criteria

Laurens¹,

François²

2017

RILEM Tech Lett

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Cathodic protection is a technique that has been used to control corrosion and increase the service life of reinforced concrete structure. Standards as EN ISO 12696 give protection criteria for both impressed current and sacrificial anodes techniques, based on potential value or decay during a depolarization sequence. The polarization (current ON) and depolarization (current OFF) are experimentally studied on a corroded concrete wall using six references electrodes and compared to a time-dependent modelling using FEM software COMSOL Multiphysics. Both experimental and numerical results show significant differences in the time response according to electrode location. This conclusion indicates that the concept of protection criteria defined by the EN ISO 12696 standard is not suitable to assess the efficiency of cathodic protection applied to reinforced concrete structure.

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“…However, considering the impedance data measured during cathodic polarisation, it appears to be questionable if the often-mentioned cathodic passivation and passivation by cathodic polarisation [12,40,41] are adequate terms to describe the processes that reduce the corrosion rate during CP of steel in concrete.…”

Section: Impedance Spectroscopy During Cathodic Polarisationmentioning

confidence: 99%

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

Eichler

Isecke

Bäßler

2009

Materials & Corrosion

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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.

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Cited by 116 publications

References 3 publications

Conventional and pulse cathodic protection of reinforced concrete: Electrochemical behavior of the steel reinforcement after corrosion and protection

Conventional and pulse cathodic protection of reinforced concrete: Electrochemical behavior of the steel reinforcement after corrosion and protection

Cathodic protection in reinforced concrete structures affected by macrocell corrosion: a discussion about the significance of the protection criteria

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

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