Eastern Hemlock in Bamboo-Reinforced Glulam
Publication: Journal of Materials in Civil Engineering
Volume 31, Issue 1
Abstract
Eastern hemlock (Tsuga canadensis) is an abundant yet underutilized low-value tree species native to the northeast region of the United States. Developing value-added markets for these trees would improve local forest management and bolster local forest economies. This paper presents an analytical and experimental investigation into the structural capabilities of double vertical glue-laminated eastern hemlock beams that are reinforced with a tensile layer of laminated veneer bamboo (LVB). LVB is a sustainable engineered bamboo product with appreciable and reliable tensile strength. This study examines the effect of LVB reinforcement on failure modes, bending strength, stiffness, ductility, and design values of eastern hemlock beams. Analytical methods are presented for modeling nonlinear structural behavior of beams in bending and inspecting failure modes for different wood strengths, followed by finite-element modeling of both reinforced and unreinforced beams. Four-point bending tests were conducted and the results confirmed the analytical predictions. Tests indicated a 16% increase in beam stiffness and an 81% increase in characteristic (fifth percentile) modulus of rupture (MOR). A methodology is proposed for determining optimum rate of reinforcement for structural performance.
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Acknowledgments
This work was supported by the USDA National Institute of Food and Agriculture, McIntire-Stennis Project 1000963. The authors would also like to thank Mr. Dan Pepin, shop manager of the Building and Construction Technology program at the University of Massachusetts, for his help during the project.
References
Alam, P., M. P. Ansell, and D. Smedley. 2009. “Mechanical repair of timber beams fractured in flexure using bonded-in reinforcements.” Compos. Part B 40 (2): 95–106. https://doi.org/10.1016/j.compositesb.2008.11.010.
ASTM. 2013. Standard test methods for mechanical properties of lumber and wood-base structural material. ASTM D4761. West Conshohocken, PA: ASTM.
ASTM. 2015. Standard methods of testing static tests of timbers in structural sizes. ASTM D198. West Conshohocken, PA: ASTM.
Bohannan, B. 1962. “Prestressing wood members.” For. Prod. J. 12 (12): 596–603.
Borri, A., M. Corradi, and A. Grazini. 2003. “FRP reinforcement of wood elements under bending loads.” In Proc., 10th Int. Conf. on Structural Faults and Repair. London: Engineering Technics Press.
Borri, A., M. Corradi, and A. Grazini. 2005. “A method for flexural reinforcement of old wood beams with CFRP materials.” Compos. Part B 36 (2): 143–153. https://doi.org/10.1016/j.compositesb.2004.04.013.
Borri, A., M. Corradi, and E. Speranzini. 2013. “Reinforcement of wood with natural fibers.” Compos. Part B 53: 1–8. https://doi.org/10.1016/j.compositesb.2013.04.039.
Bulleit, W. M., L. B. Sandberg, and G. J. Woods. 1989. “Steel-reinforced glued laminated timber.” J. Struct. Eng. 115 (2): 433–444. https://doi.org/10.1061/(ASCE)0733-9445(1989)115:2(433).
Dagher, H. J., T. E. Kimball, S. M. Shaler, and B. Abdel-Magid. 1996. Effect of FRP reinforcement on low grade eastern hemlock glulams. Madison, WI: National Conference on Wood Transportation Structures.
D’Ambrisi, A., F. Focacci, and R. Luciano. 2014. “Experimental investigation on flexural behavior of timber beams repaired with CFRP plates.” Compos. Struct. 108: 720–728. https://doi.org/10.1016/j.compstruct.2013.10.005.
de la Rosa Garcia, P., A. C. Escamilla, and M. N. G. Garcia. 2013. “Bending reinforcement of timber beams with composite carbon fiber and basalt fiber materials.” Compos. Part B 55: 528–536. https://doi.org/10.1016/j.compositesb.2013.07.016.
De Luca, V., and C. Marano. 2012. “Prestressed glulam timbers reinforced with steel bars.” Constr. Build. Mater. 30: 206–217. https://doi.org/10.1016/j.conbuildmat.2011.11.016.
Fiorelli, J., and A. A. Dias. 2003. “Analysis of the strength and stiffness of timber beams reinforced with carbon fiber and glass fiber.” Mater. Res. 6 (2): 193–202. https://doi.org/10.1590/S1516-14392003000200014.
Gilfillan, J., S. Gilbert, and G. Patrick. 2003. “The use of FRP composites in enhancing the structural behavior of timber beams.” J. Reinf. Plast. Compos. 22 (15): 1373–1388. https://doi.org/10.1177/073168403035583.
Hay, S., K. Thiessen, D. Svecova, and B. Bakht. 2006. “Effectiveness of GFRP sheets for shear strengthening of timber.” J. Compos. Constr. 10 (6): 483–491. https://doi.org/10.1061/(ASCE)1090-0268(2006)10:6(483).
Jasieńko, J. 2002a. “Experimental investigation into the force distribution in glued steel bar and wood joints.” Arch. Civ. Eng. 48 (1): 93–108.
Jasieńko, J. 2002b. “On modelling the behaviour of glued steel bar-wood joints.” Arch. Civ. Eng. 48 (2): 227–251.
Johnsson, H., T. Blanksvärd, and A. Carolin. 2007. “Glulam members strengthened by carbon fiber reinforcement.” Mater. Struct. 40 (1): 47–56. https://doi.org/10.1617/s11527-006-9119-7.
Khoshbakht, N., P. Clouston, A. Schreyer, and S. Arwade. 2018. “Computational modeling of laminated veneer bamboo dowel connections.” J. Mater. Civ. Eng. 30 (2): 04017285. https://doi.org/10.1061/(ASCE)MT.1943-5533.0002135.
Lantos, G. 1970. “The flexural behavior of steel reinforced laminated timber beams.” Wood Sci. 2 (3): 136–143.
Mahdavi, M., P. L. Clouston, and S. R. Arwade. 2011. “Development of laminated bamboo lumber: Review of processing, performance, and economical considerations.” J. Mater. Civ. Eng. 23 (7): 1036–1042. https://doi.org/10.1061/(ASCE)MT.1943-5533.0000253.
Mahdavifar, V. 2017. “Cyclic performance of connections used in hybrid cross-laminated timber.” Ph.D. thesis, Dept. of Civil Engineering/Wood Science, Oregon State Univ.
Mahdavifar, V., A. Barbosa, A. Sinha, L. Muszynski, and R. Gupta. 2017. “Hysteretic behaviour of metal connectors for hybrid (high-and low-grade mixed species) cross laminated timber.” Preprint, submitted October 21, 2017. http://arXiv.org/abs/1710.07825.
Mark, R. 1961. “Wood-aluminum beams within and beyond the elastic range. Part 1: Rectangular sections.” For. Prod. J. 11 (10): 477–484.
Micelli, F., V. Scialpi, and A. La Tegola. 2005. “Flexural reinforcement of glulam timber beams and joints with carbon fiber-reinforced polymer rods.” J. Compos. Constr. 9 (4): 337–347. https://doi.org/10.1061/(ASCE)1090-0268(2005)9:4(337).
Momentive Specialty Chemicals, Inc. 2011. “Cascophen Adhesive System G-1131.” Accessed September 26, 2018. https://m.aircraftspruce.com/catalog/pdf/cascophentech.pdf.
Nowak, T. P., J. Jasieńko, and D. Czepiżak. 2013. “Experimental tests and numerical analysis of historic bent timber elements reinforced with CFRP strips.” Constr. Build. Mater. 40: 197–206. https://doi.org/10.1016/j.conbuildmat.2012.09.106.
Peterson, J. 1965. “Wood beams prestressed with bonded tension elements.” J. Struct. Div. 91 (1): 103–120.
Plevris, N., and T. C. Triantafillou. 1992. “FRP-reinforced wood as structural material.” J. Mater. Civ. Eng. 4 (3): 300–317. https://doi.org/10.1061/(ASCE)0899-1561(1992)4:3(300).
Radford, D. W., D. Van Goethem, R. M. Gutkowski, and M. L. Peterson. 2002. “Composite repair of timber structures.” Constr. Build. Mater. 16 (7): 417–425. https://doi.org/10.1016/S0950-0618(02)00044-2.
Raftery, G. M., and A. M. Harte. 2011. “Low-grade glued laminated timber reinforced with FRP plate.” Compos. Part B 42 (4): 724–735. https://doi.org/10.1016/j.compositesb.2011.01.029.
Raftery, G. M., and C. Whelan. 2014. “Low-grade glued laminated timber beams reinforced using improved arrangements of bonded-in GFRP rods.” Constr. Build. Mater. 52: 209–220. https://doi.org/10.1016/j.conbuildmat.2013.11.044.
Schober, K. U., and K. Rautenstrauch. 2007. “Post-strengthening of timber structures with CFRP’s.” Mater. Struct. 40 (1): 27–35. https://doi.org/10.1617/s11527-006-9128-6.
Sliker, A. 1962. “Reinforced wood laminated beams.” For. Prod. J. 12 (12): 91–96.
Svecova, D., and R. J. Eden. 2004. “Flexural and shear strengthening of timber beams using glass fibre reinforced polymer bars—An experimental investigation.” Can. J. Civ. Eng. 31 (1): 45–55. https://doi.org/10.1139/l03-069.
USDA FS (USDA Forest Service). 2013. Hemlock woolly adelgid coordinated commitment to improved. Washington, DC: USDA FS.
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Information
Published In
Journal of Materials in Civil Engineering
Volume 31 • Issue 1 • January 2019
Copyright
©2018 American Society of Civil Engineers.
History
Received: Jan 23, 2018
Accepted: Jun 25, 2018
Published online: Oct 16, 2018
Published in print: Jan 1, 2019
Discussion open until: Mar 16, 2019
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