Concrete Cover Cracking and Reinforcement Corrosion Behavior in Concrete with New-to-Old Concrete Interfaces

In reinforced concrete (RC) structures, new-to-old concrete interfaces are widely present due to precast splices, repairs, and construction joints. In this paper, both monolithic and segmental specimens were fabricated with five kinds of water–cement ratios, including ordinary and high-strength conc...

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Main Authors: Juhui Zhang, Jing Li, Yuchuan Zhao, Shikun Wang, Zhongguo Guan
Format: Article
Language:English
Published: MDPI AG 2023-08-01
Series:Materials
Subjects:
Online Access:https://www.mdpi.com/1996-1944/16/17/5969
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author Juhui Zhang
Jing Li
Yuchuan Zhao
Shikun Wang
Zhongguo Guan
author_facet Juhui Zhang
Jing Li
Yuchuan Zhao
Shikun Wang
Zhongguo Guan
author_sort Juhui Zhang
collection DOAJ
description In reinforced concrete (RC) structures, new-to-old concrete interfaces are widely present due to precast splices, repairs, and construction joints. In this paper, both monolithic and segmental specimens were fabricated with five kinds of water–cement ratios, including ordinary and high-strength concrete. The impressed current-accelerated corrosion test was used, and the degree of reinforcement corrosion was controlled by Faraday’s Law. In the accelerated corrosion process, the concrete surface cracking, steel corrosion, and mechanical properties of the corroded steels in the segmental specimens were investigated and compared with monolithic specimens considering the pouring method, concrete strength, and the strength difference between new and old concrete. The prediction of concrete cracking time was also discussed. The results indicated that, for the monolithic specimens, longitudinal cracks could be observed on the ordinary concrete surface, while no cracks were produced on a high-strength concrete surface; only the rust leaked out at the ends. For the segmental specimens, both longitudinal and transverse cracks were produced on an ordinary concrete surface, while only transverse cracks were produced at the high-strength new-to-old concrete interfaces. The steel embedded in the segmental specimens suffered more sectional loss at the new-to-old concrete interfaces. An influence coefficient based on the section loss of the rebar was proposed to evaluate the influence of interfaces on the rust uniformity of rebars. When there were differences in strength between new and old concrete, the influence of the interface on the uniformity of steel bar cross-section loss slightly increased. Based on available theoretical analysis for uniform corrosion, the concrete cracking time of the monolithic specimens was predicted, which was basically consistent with experimental phenomena. However, further research is needed to predict the service life of segmental specimens with new-to-old concrete interfaces.
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spelling doaj.art-862a20ade3984d91946b7fb8bf59c8812023-11-19T08:28:25ZengMDPI AGMaterials1996-19442023-08-011617596910.3390/ma16175969Concrete Cover Cracking and Reinforcement Corrosion Behavior in Concrete with New-to-Old Concrete InterfacesJuhui Zhang0Jing Li1Yuchuan Zhao2Shikun Wang3Zhongguo Guan4Department of Civil Engineering, University of Shanghai for Science and Technology, Shanghai 200093, ChinaDepartment of Civil Engineering, University of Shanghai for Science and Technology, Shanghai 200093, ChinaTongji Architectural Design (Group) Co., Ltd., Shanghai 200092, ChinaShanghai Construction Engineering Group Co., Ltd., Shanghai 200080, ChinaState Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, ChinaIn reinforced concrete (RC) structures, new-to-old concrete interfaces are widely present due to precast splices, repairs, and construction joints. In this paper, both monolithic and segmental specimens were fabricated with five kinds of water–cement ratios, including ordinary and high-strength concrete. The impressed current-accelerated corrosion test was used, and the degree of reinforcement corrosion was controlled by Faraday’s Law. In the accelerated corrosion process, the concrete surface cracking, steel corrosion, and mechanical properties of the corroded steels in the segmental specimens were investigated and compared with monolithic specimens considering the pouring method, concrete strength, and the strength difference between new and old concrete. The prediction of concrete cracking time was also discussed. The results indicated that, for the monolithic specimens, longitudinal cracks could be observed on the ordinary concrete surface, while no cracks were produced on a high-strength concrete surface; only the rust leaked out at the ends. For the segmental specimens, both longitudinal and transverse cracks were produced on an ordinary concrete surface, while only transverse cracks were produced at the high-strength new-to-old concrete interfaces. The steel embedded in the segmental specimens suffered more sectional loss at the new-to-old concrete interfaces. An influence coefficient based on the section loss of the rebar was proposed to evaluate the influence of interfaces on the rust uniformity of rebars. When there were differences in strength between new and old concrete, the influence of the interface on the uniformity of steel bar cross-section loss slightly increased. Based on available theoretical analysis for uniform corrosion, the concrete cracking time of the monolithic specimens was predicted, which was basically consistent with experimental phenomena. However, further research is needed to predict the service life of segmental specimens with new-to-old concrete interfaces.https://www.mdpi.com/1996-1944/16/17/5969new-to-old concrete interfacecorrosion of reinforcementconcrete surface crackingsectional lossRC structures
spellingShingle Juhui Zhang
Jing Li
Yuchuan Zhao
Shikun Wang
Zhongguo Guan
Concrete Cover Cracking and Reinforcement Corrosion Behavior in Concrete with New-to-Old Concrete Interfaces
Materials
new-to-old concrete interface
corrosion of reinforcement
concrete surface cracking
sectional loss
RC structures
title Concrete Cover Cracking and Reinforcement Corrosion Behavior in Concrete with New-to-Old Concrete Interfaces
title_full Concrete Cover Cracking and Reinforcement Corrosion Behavior in Concrete with New-to-Old Concrete Interfaces
title_fullStr Concrete Cover Cracking and Reinforcement Corrosion Behavior in Concrete with New-to-Old Concrete Interfaces
title_full_unstemmed Concrete Cover Cracking and Reinforcement Corrosion Behavior in Concrete with New-to-Old Concrete Interfaces
title_short Concrete Cover Cracking and Reinforcement Corrosion Behavior in Concrete with New-to-Old Concrete Interfaces
title_sort concrete cover cracking and reinforcement corrosion behavior in concrete with new to old concrete interfaces
topic new-to-old concrete interface
corrosion of reinforcement
concrete surface cracking
sectional loss
RC structures
url https://www.mdpi.com/1996-1944/16/17/5969
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AT shikunwang concretecovercrackingandreinforcementcorrosionbehaviorinconcretewithnewtooldconcreteinterfaces
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