Application of a New System of Self-Tensioning to the Design of Large-Span Wood Floor Framings
Publication: Journal of Structural Engineering
Volume 142, Issue 6
Abstract
This study describes a self-tensioning system in which the gravitational loads acting on a horizontal structural element are automatically converted to a posttensioning force on that component. The self-tensioning effect has a variable intensity, constantly adjusted depending on the applied service loads. The self-tensioning is eccentrically applied over the cross section, and it generates a negative moment that compensates the deformations due to the gravitational loads. The system can be utilized in beams, slabs, and structural framings of different materials and can be implemented using different mechanical and hydraulic solutions. The study describes the operation of a mechanical solution for the self-tensioning system and analyzes its behavior in large-span timber floor framings. When combined with conventional pretensioning, the self-tensioning system notably improves the strength and deformation behavior and permits a design of timber floor framings with a total height of 0.03 times the span length, achieving relative deflections below 1/1,000 of the span for the service loads of the structure.
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Acknowledgments
This study is part of a research project entitled “High-performance prefabricated systems of pretensioned wood laminate with non-bonded tendons,” financed by the Ministry of Economy and Competitiveness of the Kingdom of Spain and the European Fund for Regional Development.
References
Alhayek, H., and Svecova, D. (2012). “Flexural stiffness and strength of GFRP-reinforced timber beams.” J. Compos. Constr., 245–252.
Borri, A., Corradi, M., and Speranzini, E. (2013). “Reinforcement of wood with natural fibers.” Compos. Part B: Eng., 53(1), 1–8.
Brunner, M., and Schnüriger, M. (2004). “Timber beams strengthened with prestressed fibres: Delamination.” Proc., 8th World Conf. on Timber Engineering, A. Ranta-Maunus and T. Toratti, eds., Vol. I, Finnish Association of Civil Engineers RI, Helsinki, Finland, 345–350.
Buchanan, A., Palermo, A., Carradine, D., and Pampanin, S. (2011). “Post-tensioned timber frame buildings.” Struct. Eng., 89(17), 24–30.
CEN (European Committee for Standardization). (2002). “Eurocode 1: Actions on structures. 1-1: General actions—Densities, self-weight, imposed loads for buildings.” EN 1991-1-1, Brussels, Belgium.
CEN (European Committee for Standardization). (2013). “Timber structures. Glued laminated timber and glued solid timber. Requirements.” EN 14080, Brussels, Belgium.
D’Ambrisi, A., Focacci, F., and Luciano, R. (2014). “Experimental investigation on flexural behavior of timber beams repaired with CFRP plates.” Compos. Struct., 108(1), 720–728.
Davies, M., and Fragiacomo, M. (2011). “Long-term behavior of prestressed LVL members. I: Experimental tests.” J. Struct. Eng., 1553–1561.
De La Rosa García, P., Escamilla, A. C., and Nieves González García, M. (2013). “Bending reinforcement of timber beams with composite carbon fiber and basalt fiber materials.” Compos. Part B: Eng., 55(1), 528–536.
Dolan, C. W., Galloway, T. L., and Tsunemori, A. (1997). “Prestressed glued-laminated timber beam—Pilot study.” J. Compos. Constr., 10–16.
ETA (European Technical Assessment). (2014). “CLT—Cross laminated timber.” ETA-14/0349, Brussels, Belgium.
Gesualdo, F. A. R., and Lima, M. C. V. (2012). “An initial investigation of the inverted trussed beam formed by wooden rectangular cross section enlaced with wire rope.” Struct. Eng. Mech., 44(2), 239–255.
Iqbal, A., Pampanin, S., Palermo, A., and Buchanan, A. H. (2014). “Behaviour of post-tensioned timber columns under bi-directional seismic loading.” Bull. N. Z. Soc. Earthquake Eng., 47(1), 41–53.
Kliger, R., Al-Emrani, M., Johansson, M., and Crocetti, R. (2008). “Strengthening timber with CFRP or steel plates—Short and long-term performance.” Proc., 10th World Conf. on Timber Engineering, Vol. 1, Engineered Wood Products Association (EWPA), Madison, WI, 414–421.
Long, M. (2010). “Richmond Olympic oval.” Acoust. Today, 6(1), 8–11.
McConnell, E., McPolin, D., and Taylor, S. (2014). “Post-tensioning of glulam timber with steel tendons.” Constr. Build. Mater., 73(1), 426–433.
Morris, H., Wang, M., and Zhu, X. (2012). “Deformations and loads in an LVL building with 3-storey post-tensioned shear walls.” Proc., 12th World Conf. on Timber Engineering, P. Quenneville, ed., Vol. 3, Auckland, New Zealand, 110–117.
Palermo, A., et al. (2010). “Enhanced performance of longitudinally post-tensioned long-span LVL beams.” Proc., 11th World Conf. on Timber Engineering, Vol. 1, Trees and Timber Institute, National Research Council, 449–459.
Smith, T., et al. (2014). “Post-tensioned glulam beam-column joints with advanced damping systems: Testing and numerical analysis.” J. Earthquake Eng., 18(1), 147–167.
Triantafillou, T. C., and Deskovic, N. (1992). “Prestressed FRP sheets as external reinforcement of wood members.” J. Struct. Eng., 1270–1284.
Van Beerschoten, W., Palermo, A., Carradine, D., and Pampanin, S. (2012). “Design procedure for long-span post-tensioned timber frames under gravity loading.” Proc., 12th World Conf. on Timber Engineering, P. Quenneville, ed., Vol. 1, Auckland, New Zealand, 354–361.
Wanninger, F., and Frangi, A. (2014). “Experimental and analytical analysis of a post-tensioned timber connection under gravity loads.” Eng. Struct., 70(1), 117–129.
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Published In
Journal of Structural Engineering
Volume 142 • Issue 6 • June 2016
Copyright
© 2016 American Society of Civil Engineers.
History
Received: Jun 25, 2015
Accepted: Nov 25, 2015
Published online: Jan 13, 2016
Published in print: Jun 1, 2016
Discussion open until: Jun 13, 2016
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