Journal of Korean Society of Steel Construction (한국강구조학회 논문집)

Korean Society of Steel Construction (한국강구조학회)
권호 표지
DOI QR코드

DOI QR Code

Experimental and Numerical Study of Fire Resistance of Composite Beams

무피복 합성보의 내화성능에 대한 실험 및 해석적 연구

  • Ahn, Jae Kwon (Department of Architecture and Architectural Engineering, Seoul National University) ;
  • Lee, Cheol Ho (Department of Architecture and Architectural Engineering, Seoul National University)
  • Received : 2014.08.18
  • Accepted : 2014.11.17
  • Published : 2015.04.27
Download PDF
⟨ Previous Next ⟩

Abstract

In this paper, the standard fire resistance test under load and associated numerical study were carried out to evaluate the fire resistance of unprotected partially encased beams and slimfloor beams. The temperature evolution and the deflection increase of the composite beam specimens were investigated and the effects of the key behavioral parameters including the load ratio, the reinforcement, and the fire exposure were analyzed. The test results showed that the temperature rise of the partially encased beams and slimfloor beams is considerably slow compared to the conventional H-shape composite beams. Up to at least 90 minutes, the reinforcements in the partially encased composite beams maintained below the temperature at which the cold steel strength is sustained. Unprotected partially encased beams and slimfloor beams in the experimental program achieved the fire resistance more than 2 hours according to the limiting deflection criteria. This implies that unprotected partially encased beams and slimfloor beams can be very promising alternatives to enhancing the fire resistance of steel beams. This study also conducted the fully coupled thermal-stress analysis by using the commercial code ABAQUS to the thermal and structural behaviour of composite beams in fire. The numerical predictions provide acceptable correlations with the experimental results.

본 연구에서는 매립형 합성보와 슬림플로어보의 내화성능평가를 위한 재하가열실험 및 수치해석연구를 수행하였다. 이를 통해 화재 시 합성보의 온도 및 처짐 변화를 분석하고 하중비, 철근, 화재노출면 등의 합성보 설계변수들이 내화성능에 미치는 영향을 비교하였다. 화재실험결과 매립형 합성보와 슬림플로어보의 경우 강재의 온도상승이 일반형 합성보에 비해 상당히 지연됨을 확인하였다. 그리고 매립콘크리트 내에 보강된 철근은 최소 90분까지는 상온강도를 발휘할 수 있는 온도이하를 유지하였다. 무보강 매립형 합성보, 철근을 보강한 매립형 합성보와 슬림플로어보의 경우 처짐량 제한 기준만으로도 2시간 이상의 내화성능을 달성하였다. 이는 무피복 매립형 합성보와 슬림플로어보가 강재보의 내화성능을 증진하는 합리적인 대안이 될 수 있음을 시사한다. 합성보 재하가열실험에 대하여 ABAQUS를 활용한 유한요소해석을 수행한 결과 전체적인 처짐 양상 및 내화시간의 예측에 있어서 해석결과가 실제 실험결과를 신뢰성 있게 구현하고 있음을 확인하였다.

Keywords

References

  1. European Committee for Standardization (2005) Eurocode 4: Design of Composite Steel and Concrete Structures, Part 1.2: General Rules-Structural Fire Design, BSI, London.
  2. Piloto, P., Gavilan, A., Zipponi, M., Marini, A., Mesquita, L., and Plizzari, G. (2013) Experimental Investigation of the Fire Resistance of Partially Encased Beams, Journal of Constructional Steel Research, Vol.80, pp.121-137. https://doi.org/10.1016/j.jcsr.2012.09.013
  3. Ellobody, E. (2011) Nonlinear Behaviour of Unprotected Composite Slimfloor Steel Beams Exposed to Different Fire Conditions, Thin-Walled Structures, Vol.49, pp.762-771. https://doi.org/10.1016/j.tws.2011.02.002
  4. 김성배, 최승관, 이창남, 김상섭(2006) TSC 합성보의 내화성능에 관한 연구, 한국강구조학회 논문집, 제18권, 제1호, pp.113-122. Kim, S.B. Choi, S.K., Lee, C.N., and Kim, S.S. (2006) Study on the Fire Resistance Performance of the TSC Beam, Journal of Korean Society of Steel Construction, KSSC, Vol.18, No.1, pp.113-122 (in Korean).
  5. 이승재, 강성덕, 최승관, 김명한, 김상대(2006) iTECH 합성보의 내화성능에 대한 실험연구, 한국강구조학회논문집, 한국강구조학회, 제18권, 제5호, pp.643-653. Lee, S.J. Kang, S.D., Choi, S.K., Kim, M.H., and Kim, S.D. (2006) Experimental Study on the Fire Resistance of the iTECH Composite Beam, Journal of Korean Society of Steel Construction, KSSC, Vol.18, No.5, pp.643-653 (in Korean).
  6. 김성배, 김상섭, 유덕수, 최승관(2013) 신형상 U형 하이브리드 합성보의 내화성능에 관한 연구, 한국강구조학회논문집, 한국강구조학회, 제25권, 제4호, pp.379-388. Kim, S.B. Kim, S.S., Ryu, D.S., and Choi, S.K. (2013) Fire Resistance of U-shape Hybrid Composite Beam, Journal of Korean Society of Steel Construction, KSSC, Vol.25, No.4, pp.379-388 (in Korean).
  7. 한국표준협회(2005) KS F 2257-1: 건축 구조 부재의 내화시험 방법-일반요구사항, 한국표준협회. Korea Standard Association (2005) KS F 2257-1: Methods Fire Resistance Test for Elements of Building Construction-General Requirements, KSA (in Korean).
  8. International Standards Organization (1999) ISO 834-1: Fire Resistance Test-Elements of Building Construction, ISO, Geneva.
  9. 한국표준협회(2006) KS F 2257-6: 건축 구조 부재의 내화시험 방법-보의 성능조건, 한국표준협회. Korea Standard Association (2006) KS F 2257-6: Methods Fire Resistance Test for Elements of Building Construction-Specific Requirements for Beams, KSA (in Korean).
  10. British Standard Institution (1987) BS 476: Fire Tests on Building Materials and Structures, Part 20: Method for Determination of the Fire Resistance of Elements of Construction (General Principles), BSI, London.
  11. ABAQUS (2010) ABAQUS Analysis User's Manual, SIMULIA.
  12. Bailey, C.G., Newman, G.M., and Simms, W.I. (1999) Design of Steel Framed Buildings without Applied Fire Protection, The Steel Construction Institute, UK.
  13. Incropera, F.P. and DeWitt, D.P. (2002) Fundamental of Heat and Mass Transfer, John Wiley & Sons, USA.

Cited by

  1. Nonlinear Thermo-mechanical Analysis Considering Heat Flow under Fire Conditions vol.29, pp.4, 2016, https://doi.org/10.7734/COSEIK.2016.29.4.369
  2. 재하된 H형강 휨재의 열응력해석을 이용한 한계온도 산정 vol.27, pp.4, 2015, https://doi.org/10.7781/kjoss.2015.27.4.387
  3. BESTOBEAM 전단연결재의 길이에 따른 전단 내력 평가 vol.27, pp.5, 2015, https://doi.org/10.7781/kjoss.2015.27.5.483
  4. ANSYS를 이용한 화재 후 온도에 따른 합성보 성능에 관한 해석적 연구 vol.20, pp.1, 2015, https://doi.org/10.5762/kais.2019.20.1.391
  5. Evaluation of Critical Temperature in Flexural Member Using Fire Resistant Steels Based on Analytical Method vol.31, pp.6, 2019, https://doi.org/10.7781/kjoss.2019.31.6.401
  6. The Effect of Temperature Characteristics Toward Composite Beams with Fire Conditions Subjected Vertical Loading vol.32, pp.3, 2015, https://doi.org/10.7781/kjoss.2020.32.3.189
  7. Fire Resistance of Steel Composite Beams without Fire Protection vol.20, pp.5, 2015, https://doi.org/10.9798/kosham.2020.20.5.83