Strengthening Long Steel Columns of S-Sections against Global Buckling around Weak Axis Using CFRP Plates of Various Moduli
Publication: Journal of Composites for Construction
Volume 19, Issue 4
Abstract
The traditional Euler’s buckling theory of slender columns indicates that column capacity depends on flexural rigidity (EI), rather than material strength. As such, the availability of ultrahigh modulus carbon fiber-reinforced polymer (CFRP) plates, which could be much stiffer than steel, can offer a unique alternative for strengthening slender steel columns, in lieu of welding or bolting steel plates. In this study, twelve 2.6 m long steel columns of 197 slenderness ratio that represents the upper limit permitted by code were tested under concentric axial loading using pin-ended conditions. The columns were allowed to buckle around their weak axes. CFRP plates were adhesively bonded to the flanges of the steel I-shape sections in nine of the columns. The main parameters studied were the level of initial out-of-straightness [ to ], CFRP modulus (168–430 GPa), CFRP reinforcement ratio (13–34%) and the length of CFRP plate (33–95% of L). The gain in axial strength due to CFRP retrofitting ranged from 11 to 29%, depending on the various parameters. The gain generally increased as CFRP modulus, initial out-of-straightness, or CFRP reinforcement ratio increased. Global buckling consistently governed the maximum load. In the case of the 430 GPa CFRP, buckling was followed by CFRP crushing in compression, then rupture in tension.
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References
ASTM. (2000). “Standard test method for tensile properties of polymer matrix composite materials.” D 3039/D 3039M, West Conshohocken, PA.
Bambach, M. R., and Elchalakani, M. (2007). “Plastic mechanism analysis of steel SHS strengthened with CFRP under large axial deformation.” Thin Walled Struct., 45(2), 159–170.
Bambach, M. R., Jama, H. H., and Elchalakani, M. (2009). “Axial capacity and design of thin-walled steel SHS strengthened with CFRP.” Thin Walled Struct., 47(10), 1112–1121.
Canadian Standards Association. (2009). “Limit states design of steel structures.”, Mississauga, ON, Canada.
Canadian Standards Association. (2013). “General requirements for rolled or welded structural quality steel/structural quality steel.”, Mississauga, ON, Canada.
Dawood, M., and Rizkalla, S. (2010). “Environmental durability of a CFRP system for strengthening steel structures.” Constr. Build. Mater. J., 24(9), 1682–1689.
Edberg, W., Mertz, D., and Gillespie, J., Jr. (1996). “Rehabilitation of steel beams using composite materials.” Proc., Materials Engineering Conf., Materials for the New Millennium, ASCE, New York, 502–508.
Fam, A., MacDougall, C., and Shaat, A. (2009). “Upgrading steel-concrete composite girders and repair of damaged steel beams using bonded CFRP laminates.” Thin Walled Struct., 47(10), 1122–1135.
Fawzia, S., Zhao, X. L., Al-Mahaidi, R., and Rizkalla, S. (2005). “Bond characteristics between CFRP and steel plates in double strap joints.” Adv. Steel Constr., 1(2), 17–28.
Galambos, T. V. (1998). Guide to stability design criteria for metal structures, Wiley, 708–716.
Gillespie, J. W., Mertz, D. R., Kasai, K., Edberg, W. M., Demitz, J. R., and Hodgson, I. (1996). “Rehabilitation of steel bridge girders: Large scale testing.” Proc., American Society for Composites 11th Technical Conf. on Composite Materials, 231–240.
Grabovac, I., Bartholomeusz, R. A., and Baker, A. A. (1991). “Fibre composite reinforcement of metallic plates of varying thickness and contour.” Int. Conf. of Aircraft Damage Assessment and Repair, Melbourne, Australia, 231–238.
Kalavagunta, S., Naganathan, S., and Mustapha, K. N. B. (2014). “Axially loaded steel columns strengthened with CFRP.” Jordan J. Civ. Eng., 8(1), 58–69.
Sen, R., Liby, L., and Mullins, G. (2001). “Strengthening steel bridge sections using CFRP laminates.” Composites Part B, 32(4), 309–322.
Shaat, A., and Fam, A. (2006). “Axial loading tests on short and long hollow structural steel columns retrofitted using carbon fibre reinforced polymers.” Can. J. Civ. Eng., 33(4), 458–470.
Shaat, A., and Fam, A. (2007). “Fibre-element model for slender HSS columns retrofitted with bonded high-modulus composites.” J. Struct. Eng., 85–95.
Shaat, A., and Fam, A. (2008). “Repair of cracked steel girders connected to concrete slabs using carbon fiber reinforced polymer sheets.” J. Compos. Constr., 650–659.
Shaat, A., and Fam, A. (2009). “Slender steel columns strengthened using high-modulus CFRP plates for buckling control.” J. Compos. Constr., 2–12.
Shaat, A., Schnerch, D., Fam, A., and Rizkalla, S. (2004). “Retrofit of steel structures using fiber reinforced polymers (FRP): State-of-the-art.” Transportation Research Board (TRB) 83rd Annual Meeting, Transportation Research Board, Washington, DC.
Tavakkolizadeh, M., and Saadatmanesh, H. (2001). “Repair of cracked steel girders using CFRP sheets.” Proc., ISEC-01, Hawaii.
Zhao, X. L. (2013). FRP strengthened metallic structures, Taylor & Francis, U.K.
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Published In
Journal of Composites for Construction
Volume 19 • Issue 4 • August 2015
Copyright
© 2014 American Society of Civil Engineers.
History
Received: Jun 9, 2014
Accepted: Sep 15, 2014
Published online: Nov 3, 2014
Discussion open until: Apr 3, 2015
Published in print: Aug 1, 2015
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