Experimental Behavior of Prestressed LVL-Concrete Composite Beams
Publication: Journal of Structural Engineering
Volume 134, Issue 5
Abstract
The paper investigates the stiffness and strength of composite laminated veneer lumber (LVL) and concrete beams intended for use in long-span flooring systems. Quasi-static bending tests and impact tests were conducted on four, long specimens to observe the failure mechanisms and to estimate the static and dynamic properties of the systems. One specimen, with a plain LVL member, a strong shear connection, and a concrete slab, was used as a control. The other three specimens investigated the use of (i) a proprietary, lightweight nonstructural concrete panel as a slab; (ii) a straight prestressing tendon and a strong shear connection; and (iii) a draped prestressing tendon and a weaker shear connection. All four specimens had a T-shaped cross section, with the slab supported by either one or two LVL beams. The stiffness of control beam, which is mostly related to the stiffness of the shear connection, is shown to be almost three times that of a bare LVL beam, but the beam is only 74% stronger than the bare beam. The prestressing tendons are shown to have little effect on the stiffness and strength, but reduce the deflection due to permanent load, particularly when they are draped. The proprietary lightweight concrete panels are shown to provide little structural benefit.
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Acknowledgments
The technical support and financial contribution provided by Carter Holt Harvey is gratefully acknowledged, with special thanks to Hank Bier for the personal interest showed during the whole project. Particular thanks are also due to the third writer for the experimental work and results presented in this paper. The indirect support provided by the New Zealand Earthquake Commission (EQC) for the first writer is also gratefully acknowledged.
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Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 134 • Issue 5 • May 2008
Pages: 801 - 809
Copyright
© 2008 ASCE.
History
Received: May 8, 2007
Accepted: Aug 27, 2007
Published online: May 1, 2008
Published in print: May 2008
Notes
Note. Associate Editor: Sashi K. Kunnath
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