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

2012 ◽  
Vol 63 (12) ◽  
pp. 1069-1077 ◽  
Author(s):  
U. Angst ◽  
B. Elsener ◽  
A. Jamali ◽  
B. Adey
Keyword(s):  
Practical Experience ◽  
Concrete Cover ◽  
Reinforcement Corrosion ◽  
Cover Cracking ◽  
Theoretical Considerations

scholarly journals Modelling of Corrosion-Induced Concrete Cover Cracking Due to Chloride Attacking

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1440
Author(s):  
Pei-Yuan Lun ◽  
Xiao-Gang Zhang ◽  
Ce Jiang ◽  
Yi-Fei Ma ◽  
Lei Fu
Keyword(s):  
Service Life ◽  
Corrosion Current ◽  
Practical Experience ◽  
Concrete Cover ◽  
Premature Failure ◽  
Rc Structures ◽  
Structural Capacity ◽  
Cover Cracking ◽  
Deterioration Process ◽  
Cracking Process

The premature failure of reinforced concrete (RC) structures is significantly affected by chloride-induced corrosion of reinforcing steel. Although researchers have achieved many outstanding results in the structural capacity of RC structures in the past few decades, the topic of service life has gradually attracted researchers’ attention. In this work, based on the stress intensity, two models are developed to predict the threshold expansive pressure, corrosion rate and cover cracking time of the corrosion-induced cracking process for RC structures. Specifically, in the proposed models, both the influence of initial defects and modified corrosion current density are taken into account. The results given by these models are in a good agreement with practical experience and laboratory studies, and the influence of each parameter on cover cracking is analyzed. In addition, considering the uncertainty existing in the deterioration process of RC structures, a methodology based on the third-moment method in regard to the stochastic process is proposed, which is able to evaluate the cracking risk of RC structures quantitatively and predict their service life. This method provides a good means to solve relevant problems and can prolong the service life of concrete infrastructures subjected to corrosion by applying timely inspection and repairs.

Which Rust Deposition Model Should Be Used in Predicting Concrete Cover Cracking due to Reinforcement Corrosion?

2012 ◽  
Vol 468-471 ◽  
pp. 1000-1004 ◽  
Author(s):  
Roger Zou ◽  
Frank Collins
Keyword(s):  
Predictive Model ◽  
Concrete Cover ◽  
Zone Model ◽  
Reinforcement Corrosion ◽  
Rust Layer ◽  
Rc Structures ◽  
Cover Cracking ◽  
Porous Zone ◽  
Walled Cylinder ◽  
Concrete Interface

The critical amount of corroded steel that causes concrete cover cracking can be readily calculated based on thick-walled cylinder theory. However, the results may vary significantly depending on how the rust deposition is considered. There are several rust deposition hypothesis proposed in the literature for modelling concrete cover cracking of RC structures due to reinforcement corrosion. Among them, three are considered representative ones and have been widely cited in the literature. They are: (i) assumes a certain amount of rust product carried away from the rust layer and deposited within the open cracks proposed by Pantazopoulou and Papoulia; (ii) assumes all of the rust products build up around the bar and all of them are responsible for the expansive pressure proposed by Bazant; (iii) assumes certain amount of rust products deposited into a porous zone around the bar/concrete interface proposed by Liu and Weyers. In this paper, all three rust deposition hypotheses were examined for the critical amount of corrosion to induce cover cracking. When compared to the test data available from the literature, it showed that the porous zone model proposed by Liu and Weyers gives the best predictions. Thus it may be concluded that assuming a porous zone around the steel/concrete interface would be reasonable and may be adopted in developing concrete cover cracking predictive model.

Influences of Repair Materials Properties on Reinforcement Corrosion-Induced Cover Cracking Time

2017 ◽  
Vol 21 ◽  
pp. 183-189 ◽  
Author(s):  
Wanchai Yodsudjai ◽  
Ponpan Setpittayakul
Keyword(s):  
Concrete Structure ◽  
Concrete Cover ◽  
Maintenance Planning ◽  
Reinforcement Corrosion ◽  
Reinforced Concrete Structure ◽  
Materials Properties ◽  
Repair Mortar ◽  
Cover Cracking ◽  
Repair Materials ◽  
Concrete Reinforcement

Cover cracking from reinforcement corrosion is one of the major causes of deteriorations in reinforced concrete structure. If the cover cracking time can be predicted, it would be useful for maintenance planning and budget allocation. The objective of this paper was to find the influence of repair materials on concrete cover cracking time. In this study, the corrosion of concrete reinforcement was accelerated by electricity. Using three types of materials, it was found that the cover cracking time of repair mortar was the shortest followed by those of concrete and non-shrink cement grout respectively. In addition, specimens simulating repaired concrete were prepared. The cracking times of the repaired specimens were found to be about the same and were of the same order as those of repair materials only.

Concrete cover cracking due to uniform reinforcement corrosion

2013 ◽  
Vol 46 (11) ◽  
pp. 1781-1799 ◽  
Author(s):  
Anders Ole Stubbe Solgaard ◽  
Alexander Michel ◽  
Mette Geiker ◽  
Henrik Stang
Keyword(s):  
Concrete Cover ◽  
Reinforcement Corrosion ◽  
Cover Cracking

scholarly journals Concrete cover cracking caused by steel reinforcement corrosion

2011 ◽  
Vol 63 (9) ◽  
pp. 655-667 ◽  
Author(s):  
Ali S. Al-Harthy ◽  
Mark G. Stewart ◽  
John Mullard
Keyword(s):  
Concrete Cover ◽  
Steel Reinforcement ◽  
Reinforcement Corrosion ◽  
Cover Cracking

scholarly journals DAMAGE TO CONCRETE BRIDGES DUE TO REINFORCEMENT CORROSION

Transport ◽  
2002 ◽  
Vol 17 (5) ◽  
pp. 163-170 ◽  
Author(s):  
Zenonas Kamaitis
Keyword(s):  
Service Life ◽  
Concrete Structures ◽  
Steel Corrosion ◽  
Concrete Cover ◽  
Concrete Bridges ◽  
National Standards ◽  
Chloride Diffusion ◽  
Reinforcement Corrosion ◽  
Concrete Carbonation ◽  
Cover Cracking

The mechanisms of reinforcement corrosion in concrete are the subject of extensive research. Although reliable methods for predicting the corrosive deterioration of concrete structures do not yet exist. This paper describes the durability problem of reinforced concrete bridges based on the mechanisms of carbonation depth or chloride profile. The deterioration model considering concrete carbonation, chloride penetration and concrete cover cracking is adopted to describe the service life of concrete structures. The corrosion models include environmental conditions, concrete carbonation or chloride diffusion rates, quality of concrete cover, steel corrosion rates and many other factors that make the predicting of service life of structures extremely difficult. Finally, the author gives the details of the methods of durabilio/ verification and the proposals for its including in the national standards and practical guides.

Critical reagents issues & solutions for anti-drug antibody assays

Bioanalysis ◽  
2021 ◽  
Author(s):  
Laurent Vermet
Keyword(s):  
Life Cycle ◽  
Current Literature ◽  
Life Cycle Management ◽  
Practical Experience ◽  
Scientific Understanding ◽  
Pragmatic Approach ◽  
Chemical Reagents ◽  
Antibody Assays ◽  
Theoretical Considerations

Background: Anti-Drug Antibody assays (ADA) are developed and constructed with biological and chemical reagents. Capture and detector reagents as well as ADA standard are considered critical for the performance’s characteristics of a bridging assay. Current literature well describes theoretical considerations to manage critical reagents (CR) life cycle management. Nevertheless, those recommendations must be completed by a pragmatic approach which have to be exemplified. Methodology: This article intends to present and describe two study cases of bioanalytical challenge coming from the practical experience of dealing with ADA CR and offers a concrete explanation of how to solve issues. Conclusion: An appropriate management of ADA CR goes through availability anticipation, characterization and by a scientific understanding process of assay and reagents inconsistency.

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