Retrofitting of Severely Shear-Damaged Concrete T-Beams Using Externally Bonded Composites and Mechanical End Anchorage
Publication: Journal of Composites for Construction
Volume 16, Issue 6
Abstract
The effectiveness of using an externally bonded carbon-fiber-reinforced polymer (EB-CFRP) system with mechanical end anchorage to retrofit severely shear-damaged reinforced concrete (RC) beams is examined in this paper. A total of 14 tests were performed on eight RC beams with a -shaped section and low compressive strength. To represent a severe shear-damage condition, five beams were tested to failure, retrofitted, then retested to failure for a second time. Test parameters included the number of EB-CFRP layers and type of end anchorage system. The results demonstrated that retrofitting of severely shear-damaged RC -beams with EB-CFRP composites and proper mechanical end anchorage can fully restore the original shear capacity of the beams. The use of a sandwich composite panel in combination with a threaded anchor rod inserted through the entire web width (thru-bolt) as an end anchorage system was more effective than using the panel with side powder-actuated fasteners. Increasing the number of EB-CFRP layers did not result in additional gain in shear capacity. The accuracy and validity of four different international guidelines/standards were examined by comparing their predictions with the experimental results.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors wish to express their gratitude to the UAE University and Emirates Foundation grant no. 2009/052 for financing this research work. The authors would like to thank Mr. Abdelrahman Al-Sallamin, Eng. Tarek Salah, and Mr. Faisel Abdel-Wahab for their assistance throughout testing.
References
American Concrete Institute (ACI). (2005). “Building code requirements for structural concrete and commentary.”, Farmington Hills, MI.
American Concrete Institute (ACI). (2008). “Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures.”, Farmington Hills, MI.
Bousselham, A., and Chaallal, O. (2006). “Behavior of RC T-beams strengthened in shear with CFRP: An experimental study.” ACI Struct. J., ICE, Melbourne, Australia 103(3), 339–347.
Brancaccio, A., Belarbi, A., and Bae, S. (2009). “Behavior of RC T-Beams strengthened in shear with externally bonded FRP sheets.” Proc., 9th Int. Symp. on Fiber-Reinforced Polymer Reinforcement for Concrete Structures (FRPRCS-9), ICE, Melbourne, Australia.
Carolin, A., and Taljsten, B. (2005). “Experimental study of strengthening for increased shear bearing capacity.” J. Compos. Constr., 9(6), 488–496.
Chaallal, O., Mofidi, A., Benmokrane, B., and Neale, K. W. (2011). “Embedded through-section FRP rod method for shear strengthening of RC beams: Performance and comparison with existing techniques.” J. Compos. Constr., 15(3), 60–68.
Chaallal, O., Shahawy, M., and Hassan, M. (2002). “Performance of reinforced concrete T-girders strengthened in shear with CFRP fabrics.” ACI Struct. J., 99(3), 335–343.
Chen, J. F., and Teng, J. G. (2003). “Shear capacity of FRP-strengthened RC beams: FRP debonding.” Constr. Build. Mater., 17(1), 27–41.
Consiglio Nazionale delle Ricerche (CNR). (2004). “Guidelines for design and construction of externally bonded FRP systems for strengthening existing structures.”, Rome.
European Committee for Standardization (CEN). (2004). “Design of concrete structures, part 1-1, general rules and rules for buildings.”, Brussels, Belgium.
Godat, A., Qu, Z., Lu, X., Labossiere, P., and Neal, K. (2010). “Size effects for reinforced concrete beams strengthened in shear with CFRP strips.” J. Compos. Constr., 14(3), 260–270.
Grande, E., Imbimbo, M., and Rasulo, A. (2009). “Effect of transverse steel on the response of RC beams strengthened in shear by FRP: Experimental study.” J. Compos. Constr., 13(5), 405–413.
International Federation for Structural Concrete (fib). (2001). “Externally bonded FRP reinforcement for RC structures.”, Lausanne, Switzerland.
Khalifa, A., and Nanni, A. (2002). “Rehabilitation of rectangular simply supported RC beams using CFRP composites.” Constr. Build. Mater., 16(3), 135–146.
Kim, Y., Quinn, K., Satrom, C., Ghannoum, W., and Jirsa, J. (2011). “Shear strengthening RC T-beams using CFRP laminates and anchors.” ACI SP-275, Fiber-Reinforced Polymer Reinforcement for Concrete Structures 10th Int. Symp., American Concrete Institute, Farmington Hills, MI.
Lamanna, A., Bank, L., and Scott, D. (2001). “Flexural strengthening of reinforced concrete beams using fasteners and fiber-reinforced polymer strips.” ACI Struct. J., 98(3), 368–376.
Lee, J., Lopez, M., and Bakis, C. (2009). “Slip effects in reinforced concrete beams with mechanically fastened FRP strip.” Cem. Concr. Compos., 31(7), 496–504.
Miller, A., Rosenboom, O., and Rizkalla, S. (2007). “Repair of prestressed concrete bridge girders with FRP.” Proc., 8th Int. Symp. on Fiber-Reinforced Polymer Reinforcement for Concrete Structures (FRPRCS-8), Univ. of Patras, Patras, Greece.
Ortega, C., Belarbi, A., and Bae., S. (2009). “End anchorage of externally bonded FRP sheets for the case of shear strengthening of concrete girders.” Proc., 9th Int. Symp. on Fiber-Reinforced Polymer Reinforcement for Concrete Structures (FRPRCS-9), ICE, Melbourne, Australia.
Pellegrino, C., and Modena, C. (2006). “Fiber reinforced polymer shear strengthening of reinforced concrete beams: Experimental study and analytical modeling.” ACI Struct. J., 103(5), 720–728.
Standards Australia. (2008). “Design handbook for RC structures retrofitted with FRP and metal plates: Beams and slabs.” HB 305-2008, Sydney, NSW 2001, Australia.
Teng, J., Chen, J., Smith, S., and Lam, L. (2002). “Shear strengthening of beams.” Chapter_4, FRP-strengthened RC structures, Wiley, Chichester, UK, 103–134.
Triantafillou, T., and Antonopoulos, C. (2000). “Design of concrete flexural members strengthened in shear with FRP.” J. Compos. Constr., 4(4), 198–205.
Zhang, Z., Hsu, C., and Moren, J. (2004). “Shear strengthening of reinforced concrete deep beams using carbon fiber reinforced polymer laminates.” J. Compos. Constr., 8(5), 403–414.
Information & Authors
Information
Published In
Journal of Composites for Construction
Volume 16 • Issue 6 • December 2012
Pages: 693 - 704
Copyright
© 2012 American Society of Civil Engineers.
History
Received: Nov 28, 2011
Accepted: Apr 3, 2012
Published online: Apr 10, 2012
Published in print: Dec 1, 2012
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.