Secondary Moments due to Prestressing with Different Bond at the Ultimate Limit State

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Abstract

Secondary effects of prestressing develop in statically indeterminate structures (e.g., continuous beams) due to the restraint of deformations imposed by hyperstatic restraints. These effects may significantly influence internal forces and stresses in prestressed structures. Secondary effects are influenced by the redundancy of a structural system, which raises the question of whether they will remain constant after a change in the structural system, e.g., due to the development of plastic hinge(s) in a critical cross-section(s) or after the development of a kinematic mechanism, or if they will disappear when the structure changes into a sequence of simply supported beams. The paper deals with an investigation of the behavior of continuous post-tensioned beams subjected to an ultimate load with significant secondary effects from prestressing. A total of 6 two-span beams prestressed by tendons with different bonds were tested in a laboratory with a load that changed their structural system into a kinematic mechanism. The internal forces and secondary effects of the prestressing were controlled through measurements of the reactions in all the supports. The results revealed that the secondary effects remained as a permanent part of the action on the experimental beams, even after the development of the kinematic mechanism. The results obtained confirmed that secondary effects should be included in all combinations of actions for verifications of ultimate limit states (ULS).

Andrew, R., P. - Witt, P. (1951) Prestressed Concrete - Statically Indeterminate Structures, A Symposium on Prestressed Concrete Statically Indeterminate Structures, 24-25 Sept., 1951. Papers and a discussion at a symposium organized by the Cement and Concrete Association in conjunction with the Prestressed Concrete Development Group at the Institution of Civil Engineers, London

Aravinthan,T. - Witchukreangkrai - Eakarat - Mutsuyoshi, H. (2005) Flexural Behavior of Two-Span Continuous Prestressed Concrete Girders with Highly Eccentric External Tendons, ACI Structural Journal/May-June 2005, pp. 402-411

Borzovic,V. - Laco, J. (2013) Bond of Strands Coated With Different Anticorrosion Agents. Proceedings of 20th Czech Concrete Days , 27-28.11.2013, Hradec Kralove, Czech Rep.

Burgoyne, Ch. (2005) Analysis of Continuous Prestressed Concrete Beams, www.civ.eng.cam.ac.uk/cjb/papers/cp71.pdf

Laco, J. (2015) Bond behavior of prestressing strands coated with corrosion protection emulsifiable oil. Proceedings of The 11th Central European Congress on Concrete Engineering, Innovative Concrete Technology in Practice, 1-2 Oct. 2015, Hainburg, Austria, 2015, pp. 346-349

Mattock, A. H. (1983) Secondary moments and moment redistribution in ACI318-77 Code. In M. Z. Cohn (Ed.), Int. Symposium on Nonlinearity and Continuity in Prestressed Concrete, Vol. 3, pp. 27-48. University of Waterloo, Ontario, Canada.

Moravčík, M. (2017) Design of prestressed concrete structures according to European standards edited by ŽU in Žilina, 2017, press EDIS - publishing center ŽU, ISBN 978-80-554-1354-9

Vitek, J. - Čitek, D. (2015) Consequences of Reduced Bond of Prestressing Strands. Proceedings of The 11th Central European Congress on Concrete Engineering, Innovative Concrete Technology in Practice, 1-2.10. 2015, Hainburg, Austria, pp. 20 - 23

ETA-06/0006 (2011) VSL International Ltd.: European Technical Approval No. ETA-06/0006

Response-2000. Reinforced Concrete Sectional Analysis using the Modified Compression Field Theory, program written by Evan C.Bentz, University of Toronto

Slovak Journal of Civil Engineering

The Journal of Slovak University of Technology

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