Sagging and Hogging Strengthening of Continuous Unbonded Posttensioned HSC Beams by NSM and EBR
Publication: Journal of Composites for Construction
Volume 20, Issue 2
Abstract
Continuous unbonded posttensioned concrete beams might require strengthening to cope with higher demands. Strengthening with carbon-fiber-reinforced plastics (CFRP) is a viable option; however, because of the limited number of studies in this area and lack of experimental data, the guidelines covered only bonded prestressed concrete members, in particular when these are made from high-strength concrete (HSC). This paper reports on the results of an experimental investigation on the flexural behavior of continuous unbonded posttensioned HSC beams strengthened using CFRP. In this application, the CFRP is either externally bonded reinforcement (EBR) or internally near-surface mounted (NSM) in both hogging and sagging regions. The results show that both service and ultimate states of continuous unbonded posttensioned concrete beams were considerably improved by CFRP strengthening, and also that the efficiency of the NSM method is greater than that of the EBR method, especially in crack propagation and ultimate load.
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Acknowledgments
The authors would like to acknowledge Khansar metal industries for providing the prestressing strand, Radyab Company for providing CFRP laminate, and also Amin R. Dortajnejad and Mohamad Maghsoudi for assisting in the construction of the specimens. Thanks are also due to the faculty of Civil Engineering at the Shahid Bahonar University of Kerman for providing the laboratory test facilities.
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Published In
Journal of Composites for Construction
Volume 20 • Issue 2 • April 2016
Copyright
© 2015 American Society of Civil Engineers.
History
Received: Mar 18, 2015
Accepted: Jul 16, 2015
Published online: Sep 11, 2015
Discussion open until: Feb 11, 2016
Published in print: Apr 1, 2016
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