Reinforcement Corrosion in Concrete Exposed to the North Sea for More than 60 Years

Melchers, Robert E.; Li, C. Q.

doi:10.5006/1.3319158

Cited by 19 publications

(21 citation statements)

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“…Melchers and Li 32 reported the results of a laboratory examination of precast reinforced concrete elements that had been exposed to marine environment for more than 60 years. The elements form a 1.5 km long promenade railing directly located at the North Sea in Scotland.…”

Section: Examples From Practicementioning

confidence: 99%

Concrete cover cracking owing to reinforcement corrosion – theoretical considerations and practical experience

Angst

Elsener

Jamali

et al. 2012

Materials & Corrosion

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Reinforcement corrosion might lead to cracking and spalling of the concrete cover owing to the volume expansion associated with the deposition of some of the possible corrosion products. This is not only aesthetically unpleasing, it might also accelerate deterioration processes or become a safety issue for passing traffic. The present paper discusses first the mechanisms of carbonation‐ and chloride‐induced reinforcement corrosion and considers the chemistry of aqueous iron in order to identify the type of corrosion products as well as their location of formation. Furthermore, practical examples are summarised in order to compare the documented behaviour of a number of real structures with the theoretical considerations made. It is shown that for the case of purely chloride‐induced (pitting) corrosion, precipitation of corrosion products is strongly delayed or may even not occur. Implications are discussed with respect to time‐to‐corrosion prediction models and visual inspection of reinforced concrete structures. Both the theoretical considerations and the practical experience illustrate that relying on outwardly visible signs to detect internally on‐going corrosion must be done with caution if localised reinforcement corrosion cannot be excluded.

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Section: Examples From Practicementioning

confidence: 99%

Concrete cover cracking owing to reinforcement corrosion – theoretical considerations and practical experience

Angst

Elsener

Jamali

et al. 2012

Materials & Corrosion

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“…The thickness of concrete cover is emphasized in this paper as one of the key factors determining the durability of reinforced concrete structural elements susceptible to the aggressive influence of the external environment, especially in the context of the corrosion risk of reinforcement [4,5]. This thickness determines the speed of penetration of aggressive substances deep into the reinforced concrete element, which results in damage to the passive layer on the bars and initiation of reinforcement corrosion processes.…”

Section: Introductionmentioning

confidence: 99%

“…A diffractogram of a sample of concrete taken from loggia wall near point(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). Signs: C-Calcite, Q-Quartz, and G-Gypsum.…”

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confidence: 99%

Manufacturing Errors of Concrete Cover as a Reason of Reinforcement Corrosion in a Precast Element—Case Study

et al. 2019

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The article concerns the assessment of technical condition of the precast loggia wall in a large panel building after 25 years of use as well as the cause of its damage. As a result of the study, cracks and losses of the concrete cover were found. Corrosion products were visible on exposed reinforcing rods. The reinforcement distribution and concrete cover thickness in loggia wall were estimated using a rebar detector. The corrosion assessment of reinforcement was performed using a semi non-destructive galvanostatic pulse method that allows the location of areas of corrosion and estimate the reinforcement corrosion activity. The phase composition of the concrete cover was analyzed. The test results showed an insufficient thickness of the concrete cover as the main cause of loggia wall damage. The research indicated that manufacturing errors made in the prefabrication plants affect the technical condition of precast elements and may lead to the damage of the structure well before the expected of its service life. In the case of manufacturing errors causing the implementation of an element with a concrete cover that does not meet the standard requirements for thickness and tightness, it is recommended to use protective coatings to increase the element’s durability to the designed level.

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“…There also is wide variations in concrete cover and in aggregate size. There is almost no evidence of external rust staining, perhaps because of the high rainfall in the area washing away any ferrous chlorides (Melchers & Li 2009a). Almost all the cross-sections of the 1943 concrete elements examined showed pH of 9-10 or more, with slight evidence of corrosion initiation only for local pH at reinforcement less than 9.…”

Section: Handrails At Arbroath Scotlandmentioning

confidence: 91%

Field experience and the long-term durability of reinforced concrete structures

Melchers¹

2015

Proceedings of the Second International Conference on Performance-Based and Life-Cycle Structural Engineering (PLSE 2015)

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For reinforced concrete structures the conventional wisdom is that after some years of exposure to marine conditions reinforcement corrosion is inevitable. Much attention is paid in the literature to the rate of ingress of chlorides through the concrete cover to the reinforcing bars and to ensuring highly impermeable cover and/or deeper cover, to try top prevent chloride-induced or carbonation-induced corrosion initiation. Actual field experience shows that there are many reinforced concrete structures that have survived remarkably well for many decades despite having very high chloride concentrations next to the reinforcing bars. Even with very modest concrete cover by modern standards, exhumation often finds bars free from corrosion. Detailed investigations of a number of such cases showed no corrosion if the concrete pH levels are above about 9. On the other hand, very severe reinforcement corrosion was observed in the few cases where the concrete had cracked right through the cover to the bars. Often there was no external evidence or signs of interior corrosion, including longitudinal cracking. The implications of these findings for practice are discussed.

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Reinforcement Corrosion in Concrete Exposed to the North Sea for More than 60 Years

Cited by 19 publications

References 0 publications

Concrete cover cracking owing to reinforcement corrosion – theoretical considerations and practical experience

Concrete cover cracking owing to reinforcement corrosion – theoretical considerations and practical experience

Manufacturing Errors of Concrete Cover as a Reason of Reinforcement Corrosion in a Precast Element—Case Study

Field experience and the long-term durability of reinforced concrete structures

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