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Simplified Evaluation of Shear Stiffness Degradation of Diagonally Cracked Reinforced Concrete Beams
Shear cracking in concrete box-girder bridges, which could cause excessive deflection during the serviceability limit state, cannot be effectively avoided by code-guided design. While elastic shear deformation only accounts for a small proportion of total deformation for un-cracked reinforced concre...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10342483/ https://www.ncbi.nlm.nih.gov/pubmed/37445066 http://dx.doi.org/10.3390/ma16134752 |
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author | Zheng, Kaiqi Zhou, Siyuan Zhang, Yaohui Wei, Yang Wang, Jiaqing Wang, Yuxi Qin, Xiaochuan |
author_facet | Zheng, Kaiqi Zhou, Siyuan Zhang, Yaohui Wei, Yang Wang, Jiaqing Wang, Yuxi Qin, Xiaochuan |
author_sort | Zheng, Kaiqi |
collection | PubMed |
description | Shear cracking in concrete box-girder bridges, which could cause excessive deflection during the serviceability limit state, cannot be effectively avoided by code-guided design. While elastic shear deformation only accounts for a small proportion of total deformation for un-cracked reinforced concrete (RC) beams, the magnitude of after-cracking shear deformation becomes comparable to flexural deformation for RC beams. However, there is still a lack of practical models to predict the after-cracking shear deformation of RC beams. First, six thin-webbed I beams were tested to investigate the shear stiffness degradation mechanism and the decrease ratio. Then, a very simple truss strut angle formula, which is the crucial parameter for shear stiffness, was established. Furthermore, a stiffness degradation rule for partially cracked beams was proposed considering the influence of concrete tension stiffening, which is essential for predicting the development process of after-cracking shear deformation. Finally, directly measured shear strains were used to validate the proposed shear stiffness model. The results showed that the shear stiffness drops to about 30~40% of the original stiffness after the first diagonal crack, and the remaining shear stiffness is only about 10% of the original one when the stirrup yields. Increasing the stirrup ratio is a more effective method to control shear stiffness degradation for diagonally cracked RC beams. Also, the proposed shear stiffness model well captures the main features of the shear stiffness degradation, and it provides a relatively accurate prediction of the equivalent shear stiffness at the post-cracking stage. |
format | Online Article Text |
id | pubmed-10342483 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-103424832023-07-14 Simplified Evaluation of Shear Stiffness Degradation of Diagonally Cracked Reinforced Concrete Beams Zheng, Kaiqi Zhou, Siyuan Zhang, Yaohui Wei, Yang Wang, Jiaqing Wang, Yuxi Qin, Xiaochuan Materials (Basel) Article Shear cracking in concrete box-girder bridges, which could cause excessive deflection during the serviceability limit state, cannot be effectively avoided by code-guided design. While elastic shear deformation only accounts for a small proportion of total deformation for un-cracked reinforced concrete (RC) beams, the magnitude of after-cracking shear deformation becomes comparable to flexural deformation for RC beams. However, there is still a lack of practical models to predict the after-cracking shear deformation of RC beams. First, six thin-webbed I beams were tested to investigate the shear stiffness degradation mechanism and the decrease ratio. Then, a very simple truss strut angle formula, which is the crucial parameter for shear stiffness, was established. Furthermore, a stiffness degradation rule for partially cracked beams was proposed considering the influence of concrete tension stiffening, which is essential for predicting the development process of after-cracking shear deformation. Finally, directly measured shear strains were used to validate the proposed shear stiffness model. The results showed that the shear stiffness drops to about 30~40% of the original stiffness after the first diagonal crack, and the remaining shear stiffness is only about 10% of the original one when the stirrup yields. Increasing the stirrup ratio is a more effective method to control shear stiffness degradation for diagonally cracked RC beams. Also, the proposed shear stiffness model well captures the main features of the shear stiffness degradation, and it provides a relatively accurate prediction of the equivalent shear stiffness at the post-cracking stage. MDPI 2023-06-30 /pmc/articles/PMC10342483/ /pubmed/37445066 http://dx.doi.org/10.3390/ma16134752 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Zheng, Kaiqi Zhou, Siyuan Zhang, Yaohui Wei, Yang Wang, Jiaqing Wang, Yuxi Qin, Xiaochuan Simplified Evaluation of Shear Stiffness Degradation of Diagonally Cracked Reinforced Concrete Beams |
title | Simplified Evaluation of Shear Stiffness Degradation of Diagonally Cracked Reinforced Concrete Beams |
title_full | Simplified Evaluation of Shear Stiffness Degradation of Diagonally Cracked Reinforced Concrete Beams |
title_fullStr | Simplified Evaluation of Shear Stiffness Degradation of Diagonally Cracked Reinforced Concrete Beams |
title_full_unstemmed | Simplified Evaluation of Shear Stiffness Degradation of Diagonally Cracked Reinforced Concrete Beams |
title_short | Simplified Evaluation of Shear Stiffness Degradation of Diagonally Cracked Reinforced Concrete Beams |
title_sort | simplified evaluation of shear stiffness degradation of diagonally cracked reinforced concrete beams |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10342483/ https://www.ncbi.nlm.nih.gov/pubmed/37445066 http://dx.doi.org/10.3390/ma16134752 |
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