Interaction between Time-Dependent and Second-Order Effects of Externally Posttensioned Members
Publication: Journal of Bridge Engineering
Volume 20, Issue 11
Abstract
For external tendon members subjected to sustained loads, the time-dependent effects resulting from concrete creep, shrinkage, and tendon relaxation would interact with the second-order effects resulting from the change in tendon eccentricities with the development of time-dependent deformations. This interaction should be adequately considered in a time-dependent analysis of this type of member. This paper presents a numerical model developed to predict the long-term behavior of externally prestressed concrete members at service conditions, taking into account the interaction between time-dependent and second-order effects. The proposed method of analysis is verified with the available experimental results. The time-dependent behavior of externally prestressed concrete members is evaluated, focusing on the effect of deviators and nonprestressed steel. The results demonstrate that the second-order effects result in significant changes in long-term responses other than the prestress loss. The effect of bottom nonprestressed steel on the long-term behavior is found to be limited, whereas the effect of top nonprestressed steel is very important.
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Acknowledgments
This research is sponsored by FEDER funds through the program COMPETE (Programa Operacional Factores de Competitividade) and by national funds through FCT (Fundação para a Ciência e a Tecnologia) under the project PEst-C/EME/UI0285/2013. The work presented in this paper has also been supported by FCT under Grant No. SFRH/BPD/66453/2009.
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Published In
Journal of Bridge Engineering
Volume 20 • Issue 11 • November 2015
Copyright
© 2015 American Society of Civil Engineers.
History
Received: Jan 27, 2014
Accepted: Dec 9, 2014
Published online: May 6, 2015
Discussion open until: Oct 6, 2015
Published in print: Nov 1, 2015
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