Experimental Testing of Posttensioned Timber Frames under Gravity Loading
Publication: Journal of Structural Engineering
Volume 141, Issue 9
Abstract
This paper describes the experimental testing campaign of one-bay and two-bay posttensioned timber frames under gravity loading. Long-span box beams, made of radiata pine laminated veneer lumber, were connected to columns using only the compressive force introduced by posttensioning tendons. The use of tendons with a draped profile resulted in not only semirigid beam-column connections, but also an initial precamber. Both aspects helped to satisfy deflection design limits. The load-deflection behavior of the beams, the increase in posttensioning force during testing, and the connection behavior are evaluated. Of particular interest is the gap opening of the connection, which showed a distinct bilinear moment-rotation behavior. The application of posttensioning tendons to timber frames can more than double the load-carrying capacity at serviceability limit state.
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Acknowledgments
LVL used for experimental testing was supplied by Nelson Pine Industries Ltd. and laminated by Hunter Laminates Nelson Ltd. Posttensioning equipment was supplied by BBR Contech. Thanks to Russell McConchie, Gavin Keates, and the other technicians at the Structures Laboratory at the University of Canterbury for assisting with the test setup and instrumentation. The financial support for this research from the University of Canterbury and the Structural Timber Innovation Company (STIC) was greatly appreciated.
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Published In
Journal of Structural Engineering
Volume 141 • Issue 9 • September 2015
Copyright
© 2014 American Society of Civil Engineers.
History
Received: Feb 4, 2014
Accepted: Aug 19, 2014
Published online: Oct 6, 2014
Discussion open until: Mar 6, 2015
Published in print: Sep 1, 2015
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