External Posttensioning of Reinforced Concrete Beams Using a V-Shaped Steel Rod System
Publication: Journal of Structural Engineering
Volume 140, Issue 3
Abstract
This study presents the development of an analysis method to predict the moments at first yielding and at ultimate strength of reinforced concrete beams strengthened using a V-shaped posttensioning steel rod system. The analysis requires determination of a total elongation of the external posttensioning rods, which is interdependent upon the neutral axis depth, deflection, and strains and stresses in beam components at both internal steel yielding and ultimate strength stages. The iteration algorithm was computationally programmed. The test results from a total of 14 full-scale beams were used to verify the analysis method that predicts the yield moment, moment capacity, and corresponding unbonded steel rod stresses. Finally, a flexural design method is developed for reinforced concrete beams externally posttensioned using a V-shaped steel rod system.
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Acknowledgments
The work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (2012-0005108 and 2012-005905). The authors also thank partial supports from Kyungpook National University for the first author’s visiting year at the University of Oklahoma (OU) and from Seoul National University (SNU) for the third author’s movement from OU to the present settlement at SNU. The views expressed are those of authors, and do not necessarily represent those of the sponsor.
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Published In
Journal of Structural Engineering
Volume 140 • Issue 3 • March 2014
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Sep 13, 2012
Accepted: Feb 12, 2013
Published online: Feb 14, 2013
Published in print: Mar 1, 2014
Discussion open until: Apr 5, 2014
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