Steel and Composite Structures

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

Behavior of stiffened and unstiffened CFT under concentric loading, An experimental study

  • Deifalla, Ahmed F. (Department of Structural Engineering, Faculty of Engineering, Future University in Egypt) ;
  • Fattouh, Fattouh M. (Department of Structural Engineering, Faculty of Engineering, Helwan University) ;
  • Fawzy, Mona M. (Structural Engineering, Higher Institute of Engineering, El-Shorouk Academy) ;
  • Hussein, Ibrahim S. (Department of Structural Engineering, Faculty of Engineering, Helwan University)
  • Received : 2019.04.06
  • Accepted : 2019.11.27
  • Published : 2019.12.25
⟨ Previous Next ⟩

Abstract

Concrete-filled steel tubular (CFST) beam-columns are widely used owing to their good performance. They have high strength, ductility, large energy absorption capacity and low costs. Externally stiffened CFST beam-columns are not used widely due to insufficient design equations that consider all parameters affecting their behavior. Therefore, effect of various parameters (global, local slenderness ratio and adding hoop stiffeners) on the behavior of CFST columns is studied. An experimental study that includes twenty seven specimens is conducted to determine the effect of those parameters. Load capacities, vertical deflections, vertical strains and horizontal strains are all recorded for every specimen. Ratio between outer diameter (D) of pipes and thickness (t) is chosen to avoid local buckling according to different limits set by codes for the maximum D/t ratio. The study includes two loading methods on composite sections: steel only and steel with concrete. The case of loading on steel only, occurs in the connection zone, while the other load case occurs in steel beam connecting externally with the steel column wall. Two failure mechanisms of CFST columns are observed: yielding and global buckling. At early loading stages, steel wall in composite specimens dilated more than concrete so no full bond was achieved which weakened strength and stiffness of specimens. Adding stiffeners to the specimens increases the ultimate load by up to 25% due to redistribution of stresses between stiffener and steel column wall. Finally, design equations previously prepared are verified and found to be only applicable for medium and long columns.

Keywords

References

  1. ACI Committee 318, (1999), Building code requirements for reinforced concrete, (ACI 318-99) and commentary (ACI 318R-99). Detroit: American Concrete Institute.
  2. AIJ (1997), Recommendations for design and construction of concrete filled steel tubular structures, Architectural Institutive of Japan, Tokyo, Japan.
  3. AISC (2005), Specification for Structural Steel Buildings, ANSI/AISC 360, American Institute of Steel Construction, Chicago, IL, USA.
  4. Ajel, H.A. and Abbas, A.M. (2015), "Experimental and analytical investigations of composite stub columns", Int. J. Innov. Res. Sci. Eng. Technol., 4(2).
  5. AL-Eliwi, B.J., Ekmekyapar, T., Faraj, R.H., Gogus, M.T. and AL-Shaar, A.A. (2017), "Performance of lightweight aggregate and self-compacted concrete-filled steel tube columns", Steel Compos. Struct., Int. J., 25(3), 299-314. https://doi.org/10.12989/scs.2017.25.3.299
  6. BS 5400 (1979), Steel, concrete and composite bridges: Part: 5 Code of practice for design of composite bridges, London, British Standards Institution.
  7. BS EN Eurocode 4 (1994), Design of Composite Steel and Concrete Structures, General rules and rules for buildings.
  8. DIN 50125 (2016), Testing of metallic materials - Tensile test pieces.
  9. EN 1993-1-4 (2006), Eurocode 3: Design of Steel Structures, Part 1-4: General rules, Supplementary rules for stainless steel, European Committee for Standardization CEN, Europe.
  10. Fam, A., Qie, F.S. and Rizkalla, S. (2004), "Concrete-filled steel tubes subjected to axial compression and lateral cyclic loads", J. Struct. Eng., 130(4), 631-640. https://doi.org/10.1061/(ASCE)0733-9445(2004)130:4(631)
  11. Gupta, P.K., Sarda, S.M. and Kumar, M.S. (2007), "Experimental and computational study of concrete filled steel tubular columns under axial loads", J. Constr. Steel Res., 63, 182-193. https://doi.org/10.1016/j.jcsr.2006.04.004
  12. Hajar, J.F. (2000), "Concrete-filled steel tube columns under earthquake loads", J. Progress Struct. Eng., 2, 72-81. https://doi.org/10.1002/(SICI)1528-2716(200001/03)2:1<72::AID-PSE9>3.0.CO;2-E
  13. Hajjar, J.F., Molodan, A. and Schiller, P.H. (1998), "A distributed plasticity model for cyclic analysis of concrete-filled steel tube beam-columns and composite frames", Eng. Struct., 20(4-6), 398-412. https://doi.org/10.1016/S0141-0296(97)00020-5
  14. Hu, H.T., Huang, C.S., Wu, M.H. and Wu, Y.M. (2003), "Nonlinear analysis of axially loaded concrete-filled tube columns with confinement effect", J. Struct. Eng., 129(10), 1322-1329. https://doi.org/10.1061/(ASCE)0733-9445(2003)129:10(1322)
  15. Hua, W., Wang, H.J. and Hasegawa, A. (2014), "Experimental study on reinforced concrete filled circular steel tubular columns", Steel Compos. Struct., Int. J., 17(4), 517-533. https://doi.org/10.12989/scs.2014.17.4.517
  16. Krishan, A.L., Troshkina, E.A. and Chernyshova, E.P. (2016), "Efficient design of concrete filled steel tube columns", Procedia Eng., 150, 1709-1714. https://doi.org/10.1016/j.proeng.2016.07.159
  17. Lai, M.H. and Ho, J.C.M (2014), "Behaviour of uni-axially loaded concrete-filled-steel-tube columns confined by external rings ", Struct. Des. Tall Special Build., 23(6), 403-426. https://doi.org/10.1002/tal.1046
  18. Nishiyama, I. and Morino, S. (2004), "Summary of research on concrete-filled structural steel tube column system carried out under the US-Japan cooperative research program on composite and hybrid structures", ISSN 0453-4972. Paper Number 147.
  19. Patel, V.I. (2013), "Nonlinear inelastic analysis of concrete-filled steel tubular slender beam-columns", Ph.D. Thesis; Department of Civil Engineering, College of Engineering, University of Victoria, Melbourne, Australia.
  20. Petrus, C., Hamid, H.A., Ibrahim, A. and Parke, G. (2010), "Experimental behaviour of concrete filled thin walled steel tubes with tab stiffeners", J. Constr. Steel Res., 66(7), 915-922. https://doi.org/10.1016/j.jcsr.2010.02.006
  21. Sakino, K., Nakahara, H., Morino, S. and Nishiyama, I. (2004), "Behavior of centrally loaded concrete-filled steel-tube short columns", J. Eng. Struct., 2, 180-188. https://doi.org/10.1061/(ASCE)0733-9445(2004)130:2(180)

Cited by

  1. Structural behavior of sandwich composite wall with truss connectors under compression vol.35, pp.2, 2019, https://doi.org/10.12989/scs.2020.35.2.159