Fundamental behavior of CFT beam-columns under fire loading

  • Varma, Amit H. ;
  • Hong, Sangdo ;
  • Choe, Lisa
  • Received : 2012.02.02
  • Accepted : 2013.09.09
  • Published : 2013.12.25


This paper presents experimental investigations of the fundamental behavior of concrete filled steel tube (CFT) beam-columns under fire loading. A total of thirteen specimens were tested to determine the axial force-moment-curvature-temperature behavior of CFT beam-columns. The experimental approach involved the use of: (a) innovative heating and control equipment to apply thermal loading and (b) digital image correlation with close-range photogrammetry to measure the deformations (e.g., curvature) of the heated region. Each specimen was sequentially subjected to: (i) constant axial loading; (ii) thermal loading in the expected plastic hinge region following the ASTM E119 temperature-time T-t curve; and (iii) monotonically increasing flexural loading. The effects of various parameters on the strength and stiffness of CFT beam-columns were evaluated. The parameters considered were the steel tube width, width-tothickness ratio, concrete strength, maximum surface temperature of the steel tube, and the axial load level on the composite CFT section. The experimental results provide knowledge of the fundamental behavior of composite CFT beam-columns, and can be used to calibrate analytical models or macro finite element models developed for predicting behavior of CFT members and frames under fire loading.




  1. Agarwal, A. and Varma A.H. (2011), "Design of steel columns at elevated temperatures due to fire: Effects of rotational restraints", Eng. J., AISC, 297-314.
  2. AISC (2003), Design Guide 19 - Fire Resistance of Structral Steel Framing, (eds. Ruddy, J.L., Ioannides, S. A.), AISC, Chicago, IL, USA.
  3. ASCE (2007), Standard Calculation Methods for Structural Fire Protection, ASCE/SEI/SFPE 29-05, ASCE, Reston, VA, USA.
  4. ASTM (2010), Standard Test Methods for Fire Tests of Building Construction and Materials, Active Standard ASTM E119, American Society for Testing and Materials, W. Conshohocken, PA, USA.
  5. Beyler, C.L., Beitel, J., Iwankiw, N. and Lattimer, B. (2007), "Fire resistance testing for performance-based fire design of buildings", NIST GCR 07-971, Gaithersburg, MD, USA, pp. 154.
  6. Choe, L. (2011), "Structural mechanics and behavior of steel members under fire loading", Ph.D. Dissertation, School of Civil Engineering, Purdue University, West Lafayette, IN, USA.
  7. Choe, L., Varma, A.H., Agarwal, A. and Surovek, A. (2011), "Fundamental behavior of steel beam-columns and columns under fire loading: An experimental evaluation", J. Struct. Eng., ASCE, 137(9), 954-966.
  8. ECS (2004), Eurocode 4: Design of Steel and Concrete Structures, Part 1.1, General Rules and Rules for Buildings, European Committee for Standardization, Brussels, Belgium.
  9. Han, L.H., Yang, Y.F. and Xu, L. (2002), "An experimental study calculation on the fire resistance of concrete filled SHS and RHS columns", J. Constr. Steel Res., 59(4), 427-452.
  10. Hong, S. (2007), "Fundamental behavior of stability of CFT columns under fire loading", Ph.D. Dissertation, School of Civil Engineering, Purdue University, West Lafayette, IN, USA.
  11. Hong, S. and Varma, A.H. (2009), "Analytical modeling of the standard fire behavior of loaded CFT columns", J. Constr. Steel Res., 65(1), 54-69.
  12. Hong, S. and Varma, A.H. (2010), "Predicting fire behavior of composite CFT columns using fundamental section behavior", J. ASTM Int., 7(1), 23.
  13. Huo, J., Zeng, X. and Xiao, Y. (2011), "Cyclic behaviors of concrete-filled steel tubular columns with pre-load after exposure to fire", J. Constr. Steel Res., 67(4), 727-739.
  14. IBC (2009), International Building Code, International Code Council, Inc., Falls Church, VA, USA.
  15. ISO-834 (1980), Fire Resistance Tests - Elements of Buiding Construction, International Standards Organization, Geneva, Switzerland.
  16. Kodur, V., Garlock, M. and Iwankiw, N. (2008), "National workshop on structures in fire: State- of-the-art, research and training needs", NIST GCR 07-915, NIST, U.S. Department of Commerce, Gaithersburg, MD, USA, pp. 55.
  17. Kodur, V.R. and MacKinnon, D.H. (2000), "Design of concrete-filled hollow structural steel columns for fire endurance", Eng. J., 37(1), 13-24.
  18. Lu, H., Han, L.H. and Zhao, X.L. (2010a), "Fire performance of self-consolidating concrete filled double skin steel tubular columns: Experiments," Fire Safety J., 45(2), 106-115.
  19. Lu, H., Zhao, X.L. and Han, L.H. (2010b), "Testing of self-consolidating concrete-filled double skin tubular stub columns exposed to fire", J. Constr. Steel Res., 66(8-9), 1069-1080.
  20. Maluk, C., Bisby, L.A., Terrasi, G., Krajcovic, M. and Torero, J.L. (2012a), "Novel fire testing methodology: Why, how and what now?", Proceeding of the 1st International Conference on Performance Based land Life Cycle Structural Engineering, Mini Symposium on Performance-based Fire Safety Engineering of Structures, Hong Kong, December.
  21. Maluk, C. and Bisby, L.A. (2012b), "120 years of structural fire testing: Moving away from the status quo," Invited Plenary Presentation at the II Fire Engineering Conference, Valencia, Spain, October.
  22. NFPA (2009), Building Construction and Safety Code - NFPA 5000, NFPA.
  23. NIST NCSTAR 1A (2008), "Final report on the collapse of the World Trade Center Building 7", NIST NCSTAR 1A, NIST, U.S. Department of Commerce, Gaithersburg, MD, USA.
  24. Patel, V.I., Liang, Q.Q. and Hadi, M.N.S. (2012). "Inelastic stability analysis of high strength rectangular concrete-filled steel tubular slender beam-columns," Int. Multiscale Mech., Int. J., 5(2), 91-104.
  25. Romero, M.L., Moliner, V., Espinos, A., Ibanez, C. and Hospitaler, A. (2011), "Fire behavior of axially loaded slender high strength concrete-filled tubular columns", J. Constr. Steel Res., 67(12), 1953-1965.
  26. Sadek, S., Iskander, M.G. and Liu, J. (2003), "Accuracy of digital image correlation for measuring deformations in transparent media", J. Comput. Civil Eng., 17(2), 88-96.
  27. Sakumoto, Y., Okada, T., Yoshida, M. and Taska, S. (1994), "Fire resistance of concrete filled fire resistant steel tube columns", J. Mater. Civil Eng., ASCE, 6(2), 169-184.
  28. Selden, K. (2010), Evaluation of a CMOS Digital Camera for Structural Engineering Measurements, Bowen Laboratory Research Report 2010-3, School of Civil Engineering, Bowen Laboratory, Purdue University, West Lafayette, IN, USA.
  29. Sunder, S.S., Gann, R.G., Grosshandler, W.L., Averill, J.D., Bukowski, R.W., Cauffman, S.A., Evans, D.D., Gayle, F.W., Gross, J.L., Lawson, J.R., Lew, H.S., McAllister, T.P., Nelson, H.E. and Sadek, F. (2005), "Final report of the national consortium safety team on the collapses of the World Trade Center Towers", NIST NCSTAR 1, NIST, U.S. Department of Commerce, Gaithersburg, MD, USA.
  30. Varma, A.H., Ricles, J.M., Sause, R. and Lu, L.W. (2002), "Experimental behavior of high strength square Concrete Filled Steel Tube (CFT) columns", J. Struct. Eng., ASCE, 128(3), 309-318.
  31. Varma, A.H., Srisa-Ard, J. and Hong, S. (2004), "Behavior of CFT columns and beam-column under fire loading", Proceedings of the Annual Stability Conference, Structural Stability Research Council, University of Missouri, Rolla, 557-580.
  32. Walz, J., Surovek, A., Agarwal, A., Choe, L. and Varma, A.H. (2011), "Closed-form characterization of fundamental section response of steel columns subjected to realistic fire loading", Proceeding of Annual Stability Conference, Structural Stability Research Council, Pittsburgh.
  33. Xu, Y., Fu, Y., Zhang, Y. and Zhao, X. (2011), "Fire resistance of crisscross concrete filled steel tube core columns in the different axial compression", Adv. Mater. Res., 163-167, 157-160, Trans Tech Publication, Switzerland.

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