Steel-concrete interface influence on chloride threshold for corrosion – Empirical reinforcement to theory

Kenny, Amit; Katz, Amnon

doi:10.1016/j.conbuildmat.2020.118376

Cited by 50 publications

(20 citation statements)

References 34 publications

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“…C crit ranges from 0.04 to 8.34% by binder weight, or from 0.01 to 45 in terms of [Cl -]/[OH -] molar ratio [199]. It depends on many parameters such as RH, temperature, the pH of the pore solution, local characteristics at the steel-concrete interface and the exposed area of rebar [64,77,[202][203][204][205][206][207][208].…”

Section: Depassivation and Corrosion Mechanismsmentioning

confidence: 99%

Reinforced concrete structures: A review of corrosion mechanisms and advances in electrical methods for corrosion monitoring

Rodrigues

Gaboreau

Gance

et al. 2021

Construction and Building Materials

207

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Steel corrosion is the main cause of deterioration of reinforced concrete (RC) structures. We provide an up-to-date review on corrosion mechanisms and recent advances in electrical methods for corrosion monitoring. When assessing corrosion mechanism, the inherent heterogeneity of RC structures and the significant effect of environmental factors remain major issues in data interpretations. The steel surface condition and local inhomogeneities at the steel-concrete interface appear to have an important effect on corrosion initiation. Considering uniform corrosion in atmospherically exposed reinforced concrete, the two main influencing factors of the corrosion process are the water content and the pore structure at the steel-concrete interface. However, irrespective of the depassivation mechanism, i.e. carbonation or chloride-induced corrosion, nonuniform corrosion is expected to be the main process for RC structures due to local variations in environmental exposure or the presence of interconnected rebars with different properties. Future studies may then be focused on their effect on macrocell corrosion to gain further insights in the corrosion mechanisms of RC structures. Concerning corrosion monitoring using electrical methods, the half-cell potential technique with potential mapping is accurate for locating areas with a high corrosion risk. Recent developments in the measurement of concrete resistivity have shown that the use of electrical resistivity tomography allows to consider appropriately the inherent heterogeneity of concrete and provides more insights on transport phenomena (e.g. water and salts ingress) in the material. Nevertheless, during the corrosion propagation stage, the polarization resistance remains the most important parameter to be determined as it provides quantitative information of the corrosion rate. If conventional three-electrode configuration methods can supply an accurate determination in the case of uniform corrosion, they often fail in the case of macrocell corrosion in field experiments. Recent advances have shown that a four-electrode configuration without any connection to the rebar can rather be used for the non-destructive testing and evaluation of corrosion. If studies are still required to quantify the corrosion rate, this method appears sensitive to localized corrosion and thus more suitable to field investigations. Finally, the coupling of numerical simulations with complementary electrical and other non-destructive testing methods is essential for consolidating the results to provide a better diagnosis of the service life of RC structures.

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Section: Depassivation and Corrosion Mechanismsmentioning

confidence: 99%

Reinforced concrete structures: A review of corrosion mechanisms and advances in electrical methods for corrosion monitoring

Rodrigues

Gaboreau

Gance

et al. 2021

Construction and Building Materials

207

View full text Add to dashboard Cite

show abstract

“…Observation of the corroded concrete structures shows that corrosion of steel bar initiates at the surface voids and steel-concrete interface with lower porosity can delay the initiation of corrosion (Angst et al, 2019), indicating that lower porosity of the interfacial zone can increase the chloride threshold. Kenny and Katz (2020) conducted a statistical analysis of the relationship between the chloride threshold and steel-concrete interfacial zone properties. Sixteen different concrete mixes were produced with water-cement ratios between 0.40 and 0.65, waterpowder ratios ranging from 0.91 to 1.36.…”

Section: Chloride Threshold Valuementioning

confidence: 99%

“…The chloride threshold value of concrete controls the depassivation of the steel bars and determines the initiation of the corrosion process. Kenny and Katz (2020) found that the threshold value is affected by the surface voids on the steel bar, and it increases with the decrease of the steel-concrete distance, which is determined by the pore size of the steel-concrete interfacial zone. Besides, the anode-cathode ratio a/c is also an essential parameter in the electrochemical process, when a/c 0.2, the corrosion rate of the steel can be about 100 times higher than that of a/c 10 (Chi, 2009).…”

Section: Introductionmentioning

confidence: 99%

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Determination of the Corrosion Rate of Steel Bars in Concrete Based on the Porosity of Interfacial Zone

2020

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In the present paper, a simple model to predict the corrosion rate of steel bars in concrete is developed, considering the influence of the porosity of steel-concrete interfacial zone. Firstly, a model for the porosity of the interfacial zone is developed basing on the watercement ratio gradient in the interfacial zone. Then the relationship between the porosity of the interfacial zone and the corrosion parameters of the steel bar in concrete is discussed, the anode-cathode ratio for the electrochemical corrosion process, the chloride threshold value and the resistivity of concrete are determined by the porosity of steel-concrete interfacial zone. The corrosion rate of steel bars, which is taken as the corrosion current density, is calculated by considering the cathodic concentration polarization of oxygen diffusion and resistance polarization of concrete, basing on the determined parameters above. Finally, the applicability and efficiency of the corrosion rate prediction model is verified by experiments.

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“…For example, Dobbelaere (2017) presents a potentiostat/galvanostat, design, and fabrication. Also Steinberg et al (2015) developed an open-source potentiostat ABE-Stat with the EIS technique; this technique could be used on corrosion detection, as illustrated by Eid et al (2020), Etim et al (2020), and Kenny and Katz (2020). Figure 1, presents some of the portable devices mentioned in this section, those devices are portable and their cost is a fraction of commercial laboratory equipment.…”

Section: Electronic Techniques and Portable Devicesmentioning

confidence: 99%

Portable Measurement Systems Based on Microcontrollers to Test Durability of Structures: Mini-Review

Segura

Osma

2020

Front. Built Environ.

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Corrosion presence is a recurrent concern in buildings and structures that use steel as their core or as reinforcement, due to the change of steel's properties caused by this phenomena. Therefore, methods to detect and quantify corrosion had been developed; some are based on electrical and electrochemical measurements. On reinforced concrete structures, sometimes there are exposed steel bars which are visible, but on those, a visual inspection could determine corrosion presence. There exist different options to measure the steel bars' corrosion and its level. The more straight forward consists of cutting through the concrete until the bar is exposed and connecting a measurement device there. A disadvantage of this technique is that steel has to be exposed to the environment during the measurement; as an alternative, novel contact-less electrochemical techniques are getting more popular. Recent advances in low-cost and portable electrochemical devices and embedded sensors can change how the structures are tested. Moreover, there is a discussion about how those devices, if developed for other fields as biosensors, can assist in other areas. This mini-review also gives some hints of what the future trends could be due to the combination of those areas.

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Steel-concrete interface influence on chloride threshold for corrosion – Empirical reinforcement to theory

Cited by 50 publications

References 34 publications

Reinforced concrete structures: A review of corrosion mechanisms and advances in electrical methods for corrosion monitoring

Reinforced concrete structures: A review of corrosion mechanisms and advances in electrical methods for corrosion monitoring

Determination of the Corrosion Rate of Steel Bars in Concrete Based on the Porosity of Interfacial Zone

Portable Measurement Systems Based on Microcontrollers to Test Durability of Structures: Mini-Review

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