CFRP Shear Strengthening of Reinforced-Concrete T-Beams with Corroded Shear Links
Publication: Journal of Composites for Construction
Volume 19, Issue 5
Abstract
This paper investigates the structural behavior of uncorroded as well as corroded RC T-beams strengthened in shear with either externally bonded (EB) carbon fiber–reinforced polymer (CFRP) sheets or embedded CFRP rods. Nine tests were carried out on RC T-beams having an effective depth of 295 mm and a shear span to effective depth ratio of 3.05. The investigated parameters are the shear link corrosion level (uncorroded, 7% corroded, or 12% corroded) and type of CFRP strengthening system (EB CFRP sheets or embedded CFRP rods). The unstrengthened beams with shear link corrosion levels of 7 and 12% had shear strengths that were 11 and 14%, respectively, less than the shear strength of the uncorroded unstrengthened beam. Both the embedded CFRP rods and EB CFRP sheets were effective in enhancing the shear strength of tested beams but the effectiveness of both strengthening systems decreased with increasing shear link corrosion level. The shear strength enhancement provided by the embedded CFRP rods and EB CFRP sheets decreased from 19 and 15%, respectively, to 12 and 11%, respectively, with an increase in shear link corrosion level from 7 to 12%. Corrosion of the shear links did not have a significant effect on the beam stiffness. Premature debonding limited the effectiveness of the EB CFRP sheets whereas the embedded CFRP rods did not exhibit signs of debonding and therefore showed higher effectiveness.
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Acknowledgments
The writers would like to thank Fyfe Europe for supplying the CFRP sheets and epoxy laminating resin used in the research reported in this paper. The first writer acknowledges the financial support of the U.K. Engineering and Physical Sciences Research Council.
References
Almusallam, A. A. (2001). “Effect of degree of corrosion on the properties of reinforcing steel bars.” Constr. Built Mater., 15(8), 361–368.
ASTM. (2011). “Standard practice for preparing, cleaning, and evaluating corrosion test specimens.”, West Conshohocken, PA.
Broomfield, J. P. (2007). Corrosion of steel in concrete: Understanding, investigation and repair, 2nd Ed., Taylor and Francis, London.
Chaallal, O., Mofidi, A., Benmokrane, B., and Neale, K. (2011). “Embedded through-section FRP rod method for shear strengthening of RC beams: Performance and comparison with existing techniques.” J. Compos. Constr., 374–383.
Concrete Society. (2009). “Historical approaches to the design of concrete buildings and structures.” Technical Rep. No. 70, Crowthorne, U.K.
Dirar, S., Lees, J., and Morley, C. (2012). “Precracked reinforced concrete T-beams repaired in shear with bonded carbon fiber-reinforced polymer sheets.” ACI Struct. J., 109(2), 215–224.
Dirar, S., Lees, J. M., and Morley, C. T. (2013). “Precracked reinforced concrete T-beams repaired in shear with prestressed carbon-fiber reinforced polymer straps.” ACI Struct. J., 110(5), 855–866.
El-Maaddawy, T., and Chekfeh, Y. (2013). “Shear strengthening of T-beams with corroded stirrups using composites.” ACI Struct. J., 110(5), 779–790.
El-Maaddawy, T. A., and Soudki, K. A. (2003). “Effectiveness of impressed current technique to simulate corrosion of steel reinforcement in concrete.” J. Mater. Civ. Eng., 41–47.
El-Maaddawy, T. A., and Soudki, K. A. (2007). “A model for prediction of time from corrosion initiation to corrosion cracking.” Cement Concrete Compos., 29(3), 168–175.
Eshwar, N., Nanni, A., and Ibell, T. J. (2008). “Performance of two anchor systems of externally bonded fiber-reinforced polymer laminates.” ACI Mater. J., 105(1), 72–80.
Koch, G. H., Brongers, M. P. H., Thompson, N. G., Virmani, Y. P., and Payer, J. H. (2001). “Corrosion cost and preventive strategies in the United States.”, Washington, DC.
Koutas, L., and Triantafillou, T. C. (2013). “Use of anchors in shear strengthening of reinforced concrete T-beams with FRP.” J. Compos. Constr., 101–107.
Malumbela, G., Moyo, P., and Alexander, M. (2012). “A step towards standardising accelerated corrosion tests on laboratory reinforced concrete specimens.” J. S. Afr. Inst. Civ. Eng., 54(2), 78–85.
Mofidi, A., and Chaallal, O. (2011). “Shear strengthening of RC beams with externally bonded FRP composites: Effect of strip-width-to-strip-spacing ratio.” J. Compos. Constr., 732–742.
Mofidi, A., Chaallal, O., Benmokrane, B., and Neale, K. (2012a). “Experimental tests and design model for RC beams strengthened in shear using the embedded through-section FRP method.” J. Compos. Constr., 540–550.
Mofidi, A., Chaallal, O., Benmokrane, B., and Neale, K. (2012b). “Performance of end-anchorage systems for RC beams strengthened in shear with epoxy-bonded FRP.” J. Compos. Constr., 322–331.
Mofidi, A., Thivierge, S., Chaallal, O., and Shao, Y. (2014). “Behavior of reinforced concrete beams strengthened in shear using L-shaped CFRP plates: Experimental investigation.” J. Compos. Constr., 04013033-1–04013033-8.
Rahal, K. N., and Rumaih, H. A. (2011). “Tests on reinforced concrete beams strengthened in shear using near surface mounted CFRP and steel bars.” Eng. Struct., 33(1), 53–62.
Valerio, P., and Ibell, T. J. (2003). “Shear strengthening of existing concrete bridges.” Struct. Build., 156(1), 75–84.
Valerio, P., Ibell, T. J., and Darby, A. P. (2009). “Deep embedment of FRP for concrete shear strengthening.” Struct. Build., 162(5), 311–321.
Xia, J., Jin, W. L., and Li, L. Y. (2011). “Shear performance of reinforced concrete beams with corroded stirrups in chloride environment.” Corros. Sci., 53(5), 1794–1805.
Zakaria, M., Ueda, T., Wu, Z., and Meng, L. (2009). “Experimental investigation on shear cracking behavior in reinforced concrete beams with shear reinforcement.” J. Adv. Concrete Technol., 7(1), 79–96.
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© 2014 American Society of Civil Engineers.
History
Received: Jun 24, 2014
Accepted: Nov 17, 2014
Published online: Dec 17, 2014
Discussion open until: May 17, 2015
Published in print: Oct 1, 2015
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