Errors in the electrochemical evaluation of very small corrosion rates—II. Other electrochemical techniques applied to corrosion of steel in concrete

González, José Antonio Varela; Molina, Arturo; Escudero, M.L.; Andrade, Carmen

doi:10.1016/0010-938x(85)90030-7

Cited by 41 publications

(16 citation statements)

References 10 publications

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“…4). As some researchers [45] have suggested, a suitable scan rate can be selected on the basis of actual onsite measurement conditions. In the present case, the effect is relatively weaker in the potential scan rate range from 0.3 to 1.0 mV/s.…”

Section: Lpr Testsmentioning

confidence: 99%

A comparative study on corrosion kinetic parameter estimation methods for the early stage corrosion of Q345B steel in 3.5wt% NaCl solution

Cai

Wen

Jin

2017

Int J Miner Metall Mater

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Corrosion kinetic parameters play an important role in researchers' ability to understand and predict corrosion behavior. The corrosion kinetic parameters of structural steel Q345B specimens immersed in 3.5wt% NaCl solution for 1-2 h were determined using linear polarization resistance (LPR), Tafel-curve multiparameter fitting, electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM) methods. The advantages and disadvantages of each method were investigated and discussed through comparative investigation. Meanwhile, the average corrosion rate was examined using traditional coupon tests. The results showed that the corrosion current density values estimated by EFM at a base frequency of 0.001 Hz and those obtained by Tafel-curve four-parameter fitting (TC4) are similar and consistent with the results of coupon tests. Because of their slight perturbation of the corrosion system, EIS and EFM/TC4 in collaborative application are the recommended techniques for determining the kinetics and the corresponding parameters for the homogeneous corrosion of the naked metal. In our study of the electrochemical kinetics, we obtained much more abundant and accurate electrochemical kinetic parameters through the combined use of different electrochemical methods.

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Section: Lpr Testsmentioning

confidence: 99%

A comparative study on corrosion kinetic parameter estimation methods for the early stage corrosion of Q345B steel in 3.5wt% NaCl solution

Cai

Wen

Jin

2017

Int J Miner Metall Mater

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“…Only more recently, the performance of CP applications has been studied, using electrochemical techniques as polarization resistance or impedance spectroscopy [19,38,39]. Different approaches hold for the performance of the electrochemical measurements and their applicability to reinforced cement-based materials, including possible errors, when measuring corrosion parameters [12,35,[40][41][42][43][44]. Therefore, the applicability of electrochemical techniques, especially in systems like reinforced cement-based materials, being relatively more complex [45], is subject to certain limitations, as already reported and discussed in numerous works [12,40,41,43,44,46].…”

Section: Previous Research and Motivation For The Present Investigationmentioning

confidence: 99%

Electrochemical behavior of corroded and protected construction steel in cement extract

Koleva

2011

Materials & Corrosion

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The corrosion behavior of corroded, cathodically protected and control (reference) construction steel, previously embedded in concrete, was studied in cement extract (pH 12.6, considered as concrete pore water), using cyclic voltammetry (CVA) and potentiodynamic polarization (PDP). The necessity for this investigation occurred from the previously observed and commented discrepancies in the recorded corrosion parameters for corroded and protected steel in embedded conditions [1]. Therefore this study aimed to evaluate how the ''naturally'' formed in concrete product layers (after 460 days) will influence the electrochemical behavior of the steel in cement extract. The PDP measurements reveal the lowest corrosion resistance to be for the previously corroded steel samples, for which the most active corrosion potential (À0.7 V SCE) and the highest anodic current in the potential region 0 to 0.6 V (SCE) were recorded. The CVA tests support the results from PDP and correlate the properties of the naturally formed layers with the recorded peak current densities and peak potentials with cycling. For all specimens, except the corroded ones, the peak potential initially shifts anodically, which denotes for a high corrosion resistance in the former and low corrosion resistance in the latter case. For the control and protected specimens, the passive current in the potential region of 0 to 0.6 V (SCE) remains almost unchanged with cycling, i.e. the protective properties of the initial layers remain unchanged. Thickening of the film with cycling does not influence the corrosion resistance of the previously formed layers. For the protected specimens, however, a tendency to reach a steady state and change of peak currents' height only were observed, without a pronounced shift to more anodic values. An increase in the peak current only, not accompanied by anodic shift of the peak potential, suggests that the layers in the cathodically protected specimens are more homogeneous and compact. Overall it can be stated that in cement extract, the product layer with lowest corrosion resistance is the one on the surface of the corroded steel reinforcement. The product layers in the protected specimens (although similar to control conditions) are with the highest corrosion resistance.

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“…4,35 Relevant to dc measurements, like photoresist ͑PR͒, the above considerations for possible errors, applicability, and reliability hold as well, as reported elsewhere. 2,3,11,16,36,37 In the case where corrosion rates have to be derived from PR measurements, complications and errors arise related to the following factors: 17,18 not known Tafel slopes, lack of linearity of the polarization curve in the region of corrosion potential, lack of steady state, equilibrium potentials of anodic and cathodic reactions very close to the corrosion potential, etc. Although the drawbacks of the technique are well known, it is widely applicable for fast evaluation of electrochemical behavior ͑for example, deriving R p as in this study͒ for reinforced concrete or mortar systems.…”

Section: Applicability Of Electrochemical Techniques To Reinforced Cementioning

confidence: 99%

Electrochemical Behavior, Microstructural Analysis, and Morphological Observations in Reinforced Mortar Subjected to Chloride Ingress

Koleva¹,

Breugel²,

Wit³

et al. 2007

J. Electrochem. Soc.

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The behavior of steel reinforcement was studied using electrochemical impedance spectroscopy ͑EIS͒ and polarization resistance ͑PR͒ techniques in conditions of chloride-induced corrosion in ordinary Portland cement-mortar specimens immersed in 7% NaCl for a test period of 120 days and compared to specimens immersed in demineralized water for the same period as reference specimens. This study was an initial phase of ongoing research on electrochemical methods for corrosion protection in reinforced concrete structures and aimed at investigating the applicability of widely accepted techniques as EIS and PR and their possible correlation with structural observations of the bulk matrix, relevant to cement-based materials science and product-layers distribution, to corrosion and further protection. The results indicate that the concept of EIS modeling and the components used in the latter correspond well to alterations in structural properties of the bulk matrix, while the electrochemical behavior can be additionally supported by morphological observations of the steel/cement paste interface. As is well known, corrosion in reinforced concrete is a great concern with respect to structure durability. Corrosion in concrete can take place when carbon dioxide has penetrated to the steel surface or when chloride content in the vicinity of the steel bars reaches certain threshold values.1 Consequently, breakdown of the passive layer, normally deposited on the steel surface in the concrete alkaline medium, is taking place. The assessment of the condition of reinforced structures in terms of time to initiate reinforcement corrosion, the level of damage, the performance of the system related to mechanical properties, evaluation of efficiency of protection techniques, etc. is always related to estimating corrosion rates, i.e., to determination of electrochemical parameters for the steel reinforcement in certain technical and environmental conditions. The electrochemical behavior of steel reinforcement has been extensively studied and outcomes are reported in literature. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] The intention of this work is to see how well different electrochemical techniques agree for reinforced cement-based materials rather than obtaining absolute quantitative parameters ͑such as corrosion rate for example͒ and, further, to correlate results with structural and morphological observations of the bulk matrix and the steel/cement paste interface, thus setting up a combination of techniques for the assessment of corrosion and protection in reinforced concrete. Applicability of Electrochemical Techniques to Reinforced Cement-Based MaterialsDifferent approaches hold for the performance of electrochemical ͑EC͒ measurements and their applicability to reinforced concrete, including possible errors in measuring the related corrosion parameters. 7,13,[16][17][18][19][20] A recent study 21 presents comprehensive information on the application of EC techniques in investigating the corrosion of steel reinforcemen...

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Errors in the electrochemical evaluation of very small corrosion rates—II. Other electrochemical techniques applied to corrosion of steel in concrete

Cited by 41 publications

References 10 publications

A comparative study on corrosion kinetic parameter estimation methods for the early stage corrosion of Q345B steel in 3.5wt% NaCl solution

A comparative study on corrosion kinetic parameter estimation methods for the early stage corrosion of Q345B steel in 3.5wt% NaCl solution

Electrochemical behavior of corroded and protected construction steel in cement extract

Electrochemical Behavior, Microstructural Analysis, and Morphological Observations in Reinforced Mortar Subjected to Chloride Ingress

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