Minimum Steel for Reinforced Concrete Slabs
Publication: Practice Periodical on Structural Design and Construction
Volume 26, Issue 4
Abstract
Reinforced concrete slabs are often exposed to rain and radiation from the sun, in addition to normal loads, and hence have to be provided with at least the minimum shrinkage and temperature reinforcement. Shrinkage and temperature reinforcement has traditionally been specified as a certain percentage of the cross-sectional area (about 0.12%–0.18%), which is often empirical. Moreover, this was specified when M20–M25 concrete and reinforcements of Grade Fe 415 were used, which have since been found to be inadequate by practicing engineers. Some researchers have found that the reinforcement prescribed in codes has to be increased considerably to avoid cracks due to shrinkage and temperature effects. Hence, a formula for minimum reinforcement has been developed for slabs, similar to that for beams, which provides consistent safety against collapse due to cracking. It takes into account factors that may affect the behavior of these slabs, such as concrete and steel strength and the ratio of depth to effective depth.
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Acknowledgments
I wish to acknowledge with thanks the help of Dr. Adil Dar, Postdoctoral Research Fellow, Department of Civil & Environmental Engineering, National University of Singapore, for making the drawings in this paper. I also thank Diane Harris for fixing issues regarding the language.
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Published In
Practice Periodical on Structural Design and Construction
Volume 26 • Issue 4 • November 2021
Copyright
© 2021 American Society of Civil Engineers.
History
Received: Dec 2, 2020
Accepted: Jun 1, 2021
Published online: Aug 10, 2021
Published in print: Nov 1, 2021
Discussion open until: Jan 10, 2022
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