Punching Shear Strength Model for Reinforced Concrete Flat Slabs with Openings
Publication: Journal of Structural Engineering
Volume 147, Issue 7
Abstract
A theoretical model is proposed to analyze the punching shear resistance in flat slabs of reinforced concrete in the presence of openings and stud-type shear reinforcement. Openings in flat slabs reduce resistance to punching. The magnitude of the loss of strength is influenced by the quantity, size, and position of the opening in the slab. The theoretical method presented in this work describes that once a load is applied onto the slab, a rotation occurs, giving rise to seven forces. These forces are related to the concrete and the flexural and shear reinforcement. The failure load is calculated by finding the solution of nonlinear equations developed from horizontal, vertical, and rotational balance of these forces. The failure criterion of these slabs with shear reinforcement was classified as internal or external to the shear reinforcement. The results showed theoretical breaking loads similar to those obtained experimentally, with a maximum variation of 7%.
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Data Availability Statement
Some or all data, models, or codes that support the findings of this study are available from the corresponding author upon reasonable request. The possible data to be provided are (Marques 2018):
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Estimated control perimeter values for each project code used in this work;
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Tracing of the estimated control perimeters for each code used in this work;
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Additional information from the database of flat slabs with openings and shear reinforcements for calibration the theoretical method; and
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Information about the convergence method (Newton-Raphson method) implemented to the proposed theoretical model.
Acknowledgments
The authors are grateful for the financial support that has been provided by a grant from the National Council for Scientific and Technological Development (CNPq) of Brazil.
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Published In
Journal of Structural Engineering
Volume 147 • Issue 7 • July 2021
Copyright
© 2021 American Society of Civil Engineers.
History
Received: Apr 21, 2020
Accepted: Feb 12, 2021
Published online: Apr 26, 2021
Published in print: Jul 1, 2021
Discussion open until: Sep 26, 2021
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