Flexural performance of FRP-reinforced concrete encased steel composite beams



Kara, Ilker Fatih

  • 투고 : 2015.11.30
  • 심사 : 2016.06.24
  • 발행 : 2016.08.25


This paper presents a numerical method for estimating the curvature, deflection and moment capacity of FRP-reinforced concrete encased steel composite beams (FRP-RCS). A sectional analysis is first carried out to predict the moment-curvature relationship from which beam deflection and moment capacity are then calculated. Comparisons between theoretical and experimental results of tests conducted elsewhere show that the proposed numerical technique can accurately predict moment capacity and deflection of FRP-RCS composite beam. The numerical results also indicated that beam ductility and stiffness are improved when encased steel is added to FRP reinforced concrete beams. ACI, ISIS and Bischoff models for deflection prediction compared well at low load, however, significantly underestimated the experimental results for high load levels.


fiber reinforced polymers;deflection;ductility;concrete;encased steel beam


  1. Aiello, M.A. and Ombres, L. (2002), "Structural performances of concrete beams with hybrid (fiber-reinforced polymer-steel) reinforcements", J. Compos. Constr., 6(2), 133-140. https://doi.org/10.1061/(ASCE)1090-0268(2002)6:2(133)
  2. American Concrete Institute (ACI) (2006), "Guide for the design and construction of concrete reinforced with FRP bars", ACI 440.1R-06, Farmington Hills, MI.
  3. Bischoff, P.H. (2007), "Deflection calculation of FRP reinforced concrete beams based on modifications to the existing Branson equation". J. Compos. Constr., 11(1), 4-14. https://doi.org/10.1061/(ASCE)1090-0268(2007)11:1(4)
  4. Canadian Standards Association (CSA) (2002), "Design and construction of building components with fibrereinforced polymers", CSA Standard S806-02, Rexdale, Ont., Canada.
  5. CEB-FIP (1990), "Model code for concrete structures, Comite Euro-International du Beton", Bulletin, 213/214.
  6. Chen, C.C., Weng, C., Lin, I.M. and Li, J.M. (1999), "Seismic behaviour and strength of concrete encased steel stub columns and beam-columns", Report No. MOIS 881012-1, Architecture and Building Research Institute. (in Chinese)
  7. Cheung, M.M.S. and Tsang, T.K.C. (2010), "Behaviour of concrete beams reinforced with hybrid FRP composite rebar", Adv. Struct. Eng., 13(1), 81-93. https://doi.org/10.1260/1369-4332.13.1.81
  8. Dundar, C., Tokgoz, S., Tanrikulu, A.K. and Baran, T. (2008), "Behavior of reinforced and concrete-encased composite columns subjected to biaxial bending and axial load. Building and Environment", Constr. Build. Mater., 43, 1109-20.
  9. El-Helou, R.G. and Aboutaha, R.S. (2015), "Analysis of rectangular hybrid steel-GFRP reinforced concrete beam columns", Comput. Concrete, 16(2), 245-260. https://doi.org/10.12989/cac.2015.16.2.245
  10. El-Tawil, S. and Deierlein, G.G. (1999), "Strength and ductility of concrete encased composite columns", J. Struct. Eng., 125(9), 1009-19. https://doi.org/10.1061/(ASCE)0733-9445(1999)125:9(1009)
  11. Etman, E.E. (2011), "Innovative hybrid reinforcement for flexural members", J. Compos. Constr., 15(2), 2-8. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000145
  12. Gholami, M., Mohd Sam, A.R., Marsono, A.K., Tahir, M.M. and Faridmehr, I. (2016), "Performance of steel beams strengthened with pultruded CFRP plate under various exposures", Steel Comp. Struct., 20(5), 999-1022. https://doi.org/10.12989/scs.2016.20.5.999
  13. Harris, H.G., Somboonsong, W. and Ko, F.K. (1998), "New ductile hybrid FRP reinforcing bar for concrete structures", J. Compos. Constr., 2(1), 28-37. https://doi.org/10.1061/(ASCE)1090-0268(1998)2:1(28)
  14. Lau, D. and Pam, H.J. (2010), "Experimental study of reinforced concrete beams", Eng. Struct., 32, 3857-3865. https://doi.org/10.1016/j.engstruct.2010.08.028
  15. Leung, H.Y. and Balendran, R.V. (2003), "Flexural behaviour of concrete beams internally reinforced with GFRP rods and steel rebars", Struct. Surv., 21(4), 146-157. https://doi.org/10.1108/02630800310507159
  16. Li, X., Lv H. and Zhou S. (2012), "Flexural behavior of GFRP-reinforced concrete encased steel composite beams", Constr. Build. Mater., 28, 255-262. https://doi.org/10.1016/j.conbuildmat.2011.08.058
  17. Mohamed, A.S. (2013), "Flexural behavior and design steel-GFRP reinforced concrete beams", ACI Mater. J., 10(6), 677-85.
  18. Nanni, A., Henneke M.J. and Okamoto, T. (1994), "Behavior of concrete beams with hybrid reinforcement", Constr. Build. Mater., 8(2),89-95. https://doi.org/10.1016/S0950-0618(09)90017-4
  19. Ricles, J.M. and Paboojian, S.D. (1994), "Seismic performance of steel-encased composite columns", J. Struct. Eng., 120(8), 2474-2494. https://doi.org/10.1061/(ASCE)0733-9445(1994)120:8(2474)
  20. Tan, K.H. (1997, "Behaviour of hybrid FRP-steel reinforced concrete beams", Proc., 3rd Int. Symp. on Non-Metallic (FRP) Reinforcement for Concrete Structures (FRPRCS-3), Japan Concrete Institute, Sapporo, 487-494.
  21. Weng, C.C., Yen, S.I. and Jiang, M.H. (2002), "Experimental study on shear splitting failure of full-scale composite concrete encased steel beams", J. Struct. Eng., 128(9), 1186-94. https://doi.org/10.1061/(ASCE)0733-9445(2002)128:9(1186)
  22. Wenjun, Q., Zhang, X. and Huang, H. (2009), "Flexural behavior of concrete beams reinforced with hybrid (GFRP and steel) bars", J. Compos. Constr., 13(5), 350-359. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000035
  23. Wu, G., Sun, Z.Y., Wu, Z.S. and Luo, Y.B. (2012), "Mechanical Properties of Steel-FRP Composite Bars and Performance of SFCB Reinforced Concrete Structures", Adv. Struct. Eng., 15(4), 625-635. https://doi.org/10.1260/1369-4332.15.4.625
  24. Yoon, Y.S., Yang, J.M., Min, K.H. and Shin, H.O. (2011), "Flexural strength and deflection characteristics of high strength concrete beams with hybrid FRP and steel bar reinforcement", 10th International symposium on fiber-reinforced polymer reinforcement for concrete structures 2011, FRPRCS-10, Tampa (FL, United States)/38800 Country Club Drive, Farmington Hills, MI 48331, American Concrete Institute, US.