Journal of Korean Society of Steel Construction (한국강구조학회 논문집)

Korean Society of Steel Construction (한국강구조학회)
권호 표지

An Evaluation for the Fire Resistance of Concrete-Filled Steel Square Tube Columns under Constant Axial Loads

일정 축력을 받는 콘크리트충전 각형 강관기둥의 내화성능 평가

  • 박수희 (서울시립대학교 건축공학과) ;
  • 류재용 (서울시립대학교 건축공학과) ;
  • 정경수 (포항산업과학연구원 강구조연구소) ;
  • 최성모 (서울시립대학교 건축공학과)
  • Received : 2007.06.29
  • Accepted : 2007.12.10
  • Published : 2007.12.27
Download PDF
⟨ Previous Next ⟩

Abstract

The aim of this research is to evaluate the fire resistance of concrete-filled steel square tube columns (square CFT columns) under constant axial loads by numerical analysis. The authors examined the experimental results on the fire resistance of concrete-filled steel square tube columns without fire protection. As the materials of CFT columns, steel of SPSR 400 grade and concrete of 27.5MPa and 37.8MPa strengths were used. The significant parameters were determined, such as load ratio, cross-sectional dimensions, and concrete strength. Detailed analytical simulations of fire resistance and axial deformation showed good agreement with the experimental observations. Therefore, this numerical analysis exhibited a reasonable estimation of fire resistance of the square CFT column. Results of the numerical parametric studies showed that the fire resistance of the CFT columns increased with the decrease of the concrete strength and the increase of the cross-sectional dimensions about the constant axial load ratio ($N/N_c$).

본 연구에서는 수치해석에 의해 일정 축력을 받는 콘크리트충전 각형강관(각형 CFT) 기둥의 내화성능을 평가하였다. 본 연구에 앞서 각형 CFT 기둥의 실대 내화성능평가 실험을 수행하였으며, 이로써 무내화피복 상태에서 CFT 기둥 자체만의 내화성능을 평가하였다. 강관은 SPSR 400 강재를 사용하였으며 강관 내에는 27.5MPa와 37.8MPa 강도의 콘크리트를 사용하였다. 콘크리트 강도, 작용 하중비와 기둥단면 직경을 변수로 설정하였다. 수치해석에 의해 예측된 내화성능의 타당성을 검증하기 위하여 실험결과값과 비교 평가해 본 결과, 해석값과 실험값이 서로 잘 일치하거나 해석값이 약간 저평가하고 있음을 확인하였다. 따라서 본 수치해석에 의한 CFT기둥 내화성능 예측은 타당하다고 판단된다. 내화성능 영향인자의 분석 결과, 축력비($N/N_c$)가 동일한 경우 콘크리트 강도가 적을수록 내화성능이 우수하며 단면직경이 클수록 내화성능은 향상되었다.

Keywords

References

  1. 류재용, 박수희, 정경수, 김대중, 최성모(2006), 콘크리트충전 각형 강관기둥 내화성능 영향인자의 수치해석적 분석, 한국강구조 학회학술발표대회, pp.176-183
  2. 류재용, 박수희, 한희철, 민병렬, 최성모(2007), 무피복 각형 CFT 기둥 내화성능에 관한 실험적 연구, 한국강구조학회학술발표 대회, pp.558-563
  3. 정경수, 최성모, 김동규(1999), 화재시 중심축력을 받는 콘크리트 충전 강관기둥의 구조특성, 대한건축학회논문집, Vol.15, No.6, pp.13-20
  4. 정경수, 최성모, 김동규(2000), 화재시 중심축력을 받는 콘크리트 충전 강관기둥의 내화 최대내력추정식 제안, 대한건축학회논문집, Vol.16, No.6, pp.13-20
  5. 정경수, 전상우, 김진호, 최성모, 김동규(2000), 중심축력을 받는 콘크리트충전 강관기둥의 내화성능, 대한건축학회논문집, Vol.16, No.5, pp.3-10
  6. 최성모, 박기창, 김동규(2000), 콘크리트충전 강관기둥 내화실험에 대한 고찰, 한국강구조학회논문집, Vol.12, No.6, pp.759-767
  7. 한희철, 김용구, 강선종, 최성모(2007), 국내최초 무내화피복 콘크리트충전 강관(CFT)기둥의 현장적용, 한국강구조학회지, Vol.19, No.2, pp.77-83
  8. 新都市ハウジング協會(2004), CFT造 耐火設計指針
  9. American Institute of Steel Construction(2003), Steel Design Guide 19- Fire Resistance of Structural Steel Framing, America
  10. European Committee for Standardization(1992), Eurocode No.4: Design of Composite Steel and Concrete Structures, Part 1.1: General Rules for Buildings, DD ENV 1994-1-1, British Standards Institution, UK
  11. European Committee for Standardization(2003), Eurocode No.4: Design of Composite Steel and Concrete Structures, Part 1.2: Structural Fire Design, DD ENV 1994-1-2, British Standards Institution, UK
  12. Han, L. H., Zhao, X. L., Yang, Y. F. and Feng, J. B.(2003), Experimental Study and Calculation of Fire Resistance of Concrete-Filled Hollow Steel Columns, Journal of Structural Engineering, March, pp.346-356
  13. International Organization for Standardization(ISO)(1975, 1992, 1993, 1999), ISO 834: Fire-Resistance Test-Elements of Building Construction, Switzerland
  14. Kim, D. K., Choi, S. M., Kim, J. H., Chung, K. S., Park, S. H.(2005), Experimental Study on Fire Resistance of Concrete-filled Steel Tube Column under Constant Axial Loads, International Journal of Steel Structures, No.5, pp.305-313 https://doi.org/10.12989/scs.2005.5.4.305
  15. Korean Agency for Technology and Standards(1999, 2005), KS F 2257-1: Methods of Fire Resistance Test for Elements of Building Construction- General Requirements, Korea
  16. Kodur, V. K. R.(1998), Design Equations for Evaluating Fire Resistance of SFRC-filled HSS Columns, Journal of Structural Engineering, June, pp.671-677
  17. Kodur, V. K. R.(1999), Performance-based Fire Resistance Design of Concrete-filled Steel Columns, Journal of Constructional Steel Research 51, pp.21-36 https://doi.org/10.1016/S0143-974X(99)00003-6
  18. Park, S. H., Chung, K. S., Choi, S. M. and Kim, D. K.(2006), Review of material properties for predicting the fire resistance of concrete-filled steel square tube column using the numerical method, 8th Association for steel-concrete composite structures (ASCCS 2006), China, pp.909-919
  19. Park, S. H., Chung, K. S., Choi, S. M.(2007), Effect of Thermal Properties of Structural Materials on the Fire Resistance of Concrete-Filled Steel Tube Column under Constant Axial Loads, First International Workshop on Performance, Protection, and Strengthening of Structures under Extreme Loading, Proceedings of PROTECT 2007, Whistler, Canada, August 20-22
  20. Saito, H., Morita, T. and Uesugi, H.(2004), Fire Resistance of Concrete-Filled Steel Tube Columns under Constant Axial Loads, Journal Environment and Engineering, pp.9-16
  21. Suzuki, T., Kimura, M., Kodaira, A. and Fushimi, M.(1985), Experimental Study on Fire Resistance of Concrete-Filled Square Steel Columns, Journal Construction and Engineering, AIJ, pp.77-85
  22. Wang, Y. C.(1999), The Effects of Structural Continuity on the Fire Resistance of Concrete Filled Columns in Non-sway Frames, Journal Constructional Steel Researches 50, pp.177-197 https://doi.org/10.1016/S0143-974X(98)00245-4
  23. Wang, Y. C.(2002), Steel and Composite Structures - Behaviour and Design for Fire Safety, Spon Press - Taylor & Francis Group
  24. Yin, J., Zha, X. X. and Li, L. Y.(2006), Fire resistance of axially loaded concrete filled steel tube columns, Journal of Constructional Steel Research, No.62, pp.723-729 https://doi.org/10.1016/j.jcsr.2005.11.011
  25. Zha, X. X.(2003), FE analysis of fire resistance of concrete filled CHS columns, Journal of Constructional Steel Research, No. 59, pp.769-779 https://doi.org/10.1016/S0143-974X(02)00059-7