Flexural Reinforcement of Glulam Timber Beams and Joints with Carbon Fiber-Reinforced Polymer Rods
Publication: Journal of Composites for Construction
Volume 9, Issue 4
Abstract
Fiber-reinforced polymer (FRP) composites have largely been used in combination with masonry and concrete structural elements in the last decade. Recent applications showed that new advantages may also be achieved in the field of timber structures, even if currently steel fasteners are used mainly in connecting systems. This study investigated the possibility of using carbon FRP (CFRP) rods as glued-in reinforcement of glulam beams and as glued-in connectors for glulam timber head joints that should transfer flexural moment between two adjacent beams. Half-scale beams were tested both with and without the presence of FRP reinforcement. Flexural behavior of CFRP-reinforced beams was compared with unreinforced beams that were used as control specimens. Two different amounts of CFRP reinforcement were used in the beam section. Experimental results showed a significant influence of the CFRP rods, because the reinforced beams demonstrated an increase in ultimate capacity and stiffness. Experimental results were also compared with numerical analysis, which showed good accordance with regard to the load and deflection values. Full-size head joints were prepared and tested. Flexural behavior of the joints was compared with the mechanical properties of monopiece beams that were used as reference specimens. Three different force transfer lengths were used for the construction of CFRP-timber joints. Experimental results showed that the use of CFRP rods in timber joints was successful, because the capacity of the CFRP-jointed beams was almost the same as that of the monolithic beams for the longest bond length that was adopted. This result is important in order to find an adequate alternative to traditional joints made with steel bolts and plates, which are unable to create rigid connections, increase dramatically the weight of timber structures, and may be subjected to corrosion in an aggressive environment. A numerical modeling based on the virtual work principle was also conducted and theoretical results were found in good accordance with the experimental results for the tested joint.
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Acknowledgmens
This research was supported by STRATEX srl, MAPEI spa, Hughes Brothers Inc., and the Innovation Engineering Department of the University of Lecce (Italy).
References
Dagher, H. J., Kimball, T. E., Shaler, S. M., and Abdel-Magid, B. (1996). “Effect of FRP reinforcement on low grade eastern hemlock glulams.” Proc., National Conf. on Wood Transportation Structures, Forest Products Laboratory, Madison, Wis.
Fairweather, R. H. (1999). “Beam column connections in glue laminated timber.” Research Rep. 92/5, Dept. of Civil Engineering, University of Canterbury, Christchurch, New Zealand.
Gentile, C., Svecova, D., and Rizkalla, S. (2002). “Timber beams strengthened with GFRP bars: Development and applications.” J. Compos. Constr., 6(1), 11–20.
Harvey, K., and Ansell, M. P. (2000). “Improved timber using bonded-in GFRP rods.” Proc., World Conf. on Timber Engineering, University of British Columbia, Vancouver, Canada.
Hernandez, R., Davalos, J. F., Sonti, S. S., Kim, Y., and Moody, R. C. (1997). “Strength and stiffness of reinforced yellow-poplar glued laminated beams.” Res. Paper FPL-RP-554, Forest Products Laboratory, Madison, Wis.
Komatsu, K. (1998). “Glued-in hardwood dowels as an alternative timber end-jointing device.” Otto-Graf J., 9, 135–152.
Komatsu, K., Koizumi, A., Sasaki, T., Jensen, J. L., and Ijima, Y. (1997). “Flexural behavior of GLT beams end-jointed by glued-in hardwood dowels.” Rep. CIB–W18/30-7-1, International Council for Building Research Studies and Documentation, Rotterdam, The Netherlands.
Korin, U., Buchanan, A. H., and Moss, P. J. (1999). “Effect of bar arrangement on the tensile strength of epoxied end bolts in glulam.” Proc., Pacific Timber Engineering Conf., Rotorua, New Zealand.
Moss, P. J., Buchanan, A. H., and Wong, K. L. (2000). “Moment-resisting connections in glulam beams.” Proc., World Conf. on Timber Engineering, University of British Columbia, Vancouver, Canada.
Plevris, N., and Triantafillou, T. C. (1992). “FRP-reinforced wood as structural material.” J. Mater. Civ. Eng., 4(3), 300–317.
Qiao, P., Davalos, J. F., and Zipfel, M. G. (1998). “Modeling and optimal design of composite-reinforced wood railroad crosstie.” Compos. Struct., 41, 87–96.
Scialpi, V., De Lorenzis, L., and La Tegola, A. (2003). “Bond of CFRP rods in glulam members.” Proc., Int. Conf. on Compos. Constr., D. Bruno, G. Spadea, and N. Swamy, eds., University of Calabria, Rende, Italy, 215–220.
Tingley, D. A., Gilhamand, M. S., and Scott, K. (1996). “Long term load performance of FRP reinforced glulam bridge girders.” Proc., National Conf. on Wood Transportation Structures, Forest Products Laboratory, Madison, Wis.
Townsend, P. K. (1990). “Steel dowels epoxy bonded in glue laminated timber.” Research Rep. 90/11, Dept. of Civil Engineering, University of Canterbury, Christchurch, New Zealand.
Triantafillou, T. C. (1998). “Composites: A new possibility for the shear strengthening of concrete, masonry, and wood.” Compos. Sci. Technol., 58, 1285–1295.
Triantafillou, T. C., and Deskovic, N. (1992). “Prestressed FRP sheets as external reinforcement of wood members.”J. Struct. Eng., 118(5), 1270–1284.
Information & Authors
Information
Published In
Journal of Composites for Construction
Volume 9 • Issue 4 • August 2005
Pages: 337 - 347
Copyright
© 2005 ASCE.
History
Received: Mar 29, 2004
Accepted: Nov 3, 2004
Published online: Aug 1, 2005
Published in print: Aug 2005
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