DOI QR코드

DOI QR Code

Numerical analysis of simply supported one-way reinforced concrete slabs under fire condition

  • Ding, Fa-xing (School of Civil Engineering, Central South University) ;
  • Wang, Wenjun (School of Civil Engineering, Central South University) ;
  • Jiang, Binhui (School of Civil Engineering, Central South University) ;
  • Wang, Liping (School of Civil Engineering, Central South University) ;
  • Liu, Xuemei (Department of Infrastructure Engineering, The University of Melbourne)
  • 투고 : 2019.05.11
  • 심사 : 2021.03.20
  • 발행 : 2021.04.25

초록

This paper investigates the mechanical response of simply supported one-way reinforced concrete slabs under fire through numerical analysis. The numerical model is constructed using the software ABAQUS, and verified by experimental results. Generally, mechanical response of the slab can be divided into four stages, accompanied with drastic stress redistribution. In the first stage, the bottom of the slab is under tension and the top is under compression. In the second stage, stress at bottom of the slab becomes compression due to thermal expansion, with the tension zone at the mid-span section moving up along the thickness of the slab. In the third stage, compression stress at bottom of the slab starts to decrease with the deflection of the slab increasing significantly. In the fourth stage, the bottom of the slab is under tension again, eventually leading to cracking of the slab. Parametric studies were further performed to investigate the effects of load ratio, thickness of protective layer, width-span ratio and slab thickness on the performance of the slab. Results show that increasing the thickness of the slab or reducing the load ratio can significantly postpone the time that deflection of the slab reaches span/20 under fire. It is also worth noting that slabs with the span ratio of 1:1 reached a deflection of span/20 22 min less than those of 1:3. The thickness of protective layer has little effect on performance of the slab until it reaches a deflection of span/20, but its effect becomes obvious in the late stages of fire.

키워드

참고문헌

  1. Achenbach, M., Lahmer, T. and Morgenthal, G. (2017), "Identification of the thermal properties of concrete for the temperature calculation of concrete slabs and columns subjected to a standard fire-methodology and proposal for simplified formulations", Fire Saf. J., 87, 80-86. https://doi.org/10.1016/j.firesaf.2016.12.003.
  2. Allam, S.M., Elbakry, H.M.F. and Rabeai, A.G. (2013), "Behavior of one-way reinforced concrete slabs subjected to fire", Alex. Eng. J., 52(4), 749-761. https://doi.org/10.1016/j.aej.2013.09.004.
  3. Bailey, C.G. (2004), "Membrane action of slab/beam composite floor systems in fire", Eng. Struct., 26(12), 1691-1703. https://doi.org/10.1016/j.engstruct.2004.06.006.
  4. Banerjee, D.K. (2016), "An analytical approach for estimating uncertainty in measured temperatures of concrete slab during fire", Fire Saf. J., 82, 30-36. https://doi.org/10.1016/j.firesaf.2016.03.005.
  5. Chen, L.G. (2004), "The experimental research of reinforced concrete slab", Ph.D. Dissertation, Xi'an University of Architecture and Technology, Xi'an, China. (in Chinese)
  6. Ding, F.X. and Yu, Z.W. (2006), "Behavior of concrete and circular concrete-filled steel tube columns at constant high temperatures", J. Cent. South Univ., 13(6), 726-732. https://doi.org/10.1007/s11771-006-0022-8.
  7. Ding, F.X., Li, Z., Cheng, S.S. and Yu, Z.W. (2018), "Stress redistribution of simply supported reinforced concrete beams under fire conditions", J. Cent. South Univ., 25(9), 2093-2106. https://doi.org/10.1007/s11771-018-3899-0.
  8. Dwaikat, M.B. and Kodur, V.K.R. (2009), "Hydrothermal model for predicting fire-induced spalling in concrete structural systems", Fire Saf. J., 44(3), 425-434. https://doi.org/10.1016/j.firesaf.2008.09.001.
  9. Dzolev, I., Cvetkovska, M., Ladjinovic, D. and Radonjanin, V. (2018), "Numerical analysis on the behavior of reinforced concrete frame structures in fire", Comput Concrete, 21(6), 637-647. http://doi.org/10.12989/cac.2018.21.6.637.
  10. Ellobody, E. and Bailey, C.G. (2009), "Modelling of unbonded post-tensioned concrete slabs under fire conditions", Fire Saf. J., 44(2), 159-167. https://doi.org/10.1016/j.firesaf.2008.05.007.
  11. Erdem, H. (2017), "Predicting residual moment capacity of thermally insulated RC beams exposed to fire using artificial neural networks", Comput Concrete, 19(6), 711-716. http://doi.org/10.12989/cac.2017.19.6.711.
  12. Eurocode 2 (2004), Design of Concrete Structures-Part 1.2: General Rules-Structural Fire Design, BS EN1992-1-2, British Standard Institution, London, UK.
  13. Eurocode 3 (2005), Design of Steel Structures-Part 1.2: General Rules-Structural Fire Design, BS EN 1993-1-2, British Standard Institution, London, UK.
  14. Eurocode 4 (2005), Design of Composite Steel and Concrete Structures-Part 1.2: General Rules-Structural Fire Design, BS EN 1994-1-2, British Standard Institution, London, UK.
  15. Gawin, D., Pesavento, F. and Castells, A.G. (2018), "On reliable predicting risk and nature of thermal spalling in heated concrete", Arch. Civil Mech. Eng., 18(4), 1219-1227. https://doi.org/10.1016/j.acme.2018.01.013.
  16. GB/T 50152-2012 (2012), Standard for Test Method of Concrete Structures, China Architecture & Building Press, Beijing, China.
  17. Guo, Z.H. and Shi, X.D. (2011), Experiment and Calculation of Reinforced Concrete at Elevated Temperature, Tsinghua University Press, Beijing, China.
  18. Han, L.H., Xu, L and Zhao, X.L. (2003), "Tests and analysis on the temperature field within concrete filled steel tubes with or without protection subjected to a standard fire", Adv. Struct. Eng., 6(2), 121-133. https://doi.org/10.1260/136943303769013219.
  19. Ibrahimbegovic, A., Boulkertous, A., Davenne, L., Muhasilovic, M. and Pokrklic, A. (2010), "On modeling of fire resistance tests on concrete and reinforced-concrete structures", Comput Concrete, 7(4), 285-301. https://doi.org/10.12989/cac.2010.7.4.285.
  20. ISO 834-1 (1999), Fire-Resistance Tests-Elements of Buildings Construction-Part 1: General Requirements, Switzerland.
  21. Kudryashov, V., Kien, N.T. and Lupandin, A. (2012), "Fire resistance evaluation of reinforced concrete structures", Saf. Technogen. Environ., 3, 45-49.
  22. Lee, D.H., Cheon, N.R., Kim, M., Lee, J. and Kim, K.S. (2017), "Simplified P-M interaction curve model for reinforced concrete columns exposed to standard fire", Comput Concrete, 19(5), 545-553. http://doi.org/10.12989/cac.2017.19.5.547.
  23. Li, Y.Q., Ma, D.Z. and Xu, J. (1991), Fire Design Calculation and Construction Principle of Building Structure, China Architecture & Building Press, Beijing, China. (in Chinese)
  24. Lie, T.T. (1994), "Fire resistance of circular steel columns filled with bar-reinforced concrete", J. Struct. Eng., 120(5), 1489-1509. https://doi.org/10.1061/(ASCE)0733-9445(1994)120:5(1489).
  25. Lie, T.T. and Williams-Leir, G. (1979), "Factors affecting temperature of fire-exposed concrete slabs", Fire Mater., 3(2), 74-79. https://doi.org/10.1002/fam.810030204.
  26. Omer, E., Izzuddin, B.A. and Elghazouli, A.Y. (2010a), "Failure of unrestrained lightly reinforced concrete slabs under fire, Part I: Analytical models", Eng Struct., 32(9), 2631-2646. https://doi.org/10.1016/j.engstruct.2010.04.039.
  27. Omer, E., Izzuddin, B.A. and Elghazouli, A.Y. (2010b), "Failure of unrestrained lightly reinforced concrete slabs under fire, Part II: Verification and application", Eng Struct., 32(9), 2647-2657. https://doi.org/10.1016/j.engstruct.2010.04.035.
  28. Song, T.Y. and Han, L.H. (2014), "Post-fire behaviour of concrete-filled steel tubular column to axially and rotationally restrained steel beam joint", Fire Saf. J., 69, 147-163. https://doi.org/10.1016/j.firesaf.2014.05.023.
  29. Song, T.Y., Han, L.H. and Uy, B. (2010a), "Performance of CFST column to steel beam joints subjected to simulated fire including the cooling phase", J. Constr. Steel Res., 66, 591-604. https://doi.org/10.1016/j.jcsr.2009.12.006.
  30. Song, T.Y., Han, L.H. and Yu. X.Y. (2010b), "Concrete filled steel tube stub columns under combined temperature and loading", J. Constr. Steel Res., 66(3), 369-384. https://doi.org/10.1016/j.jcsr.2009.10.010.
  31. Sun, J.X. and Gao, W. (1994), Synthetic Fire Prevention Design of Building, Tianjin Science & Technology Translation & Publishing Cooperation, Tianjin, China. (in Chinese)
  32. Sutriso, W. and Wahyuni, E. (2014), "Simplification of numerical model to analyze the uniformly heated one way reinforced concrete slabs exposed by fire", Int. J. Eng Sci., 4(6), 197-201.
  33. Wang, Y., Dong, Y.L. and Zhou, G.C. (2013), "Nonlinear numerical modeling of two-way reinforced concrete slabs subjected to fire", Comput. Struct., 119(4), 23-36. https://doi.org/10.1016/j.compstruc.2012.12.029.
  34. Yang, H., Han, L.H and Wang Y.C. (2008), "Effects of heating and loading histories on post fire cooling behaviour of concrete filled steel tubular columns", J. Constr. Steel Res., 64(5), 123-134. https://doi.org/10.1016/j.jcsr.2007.09.007.
  35. Yang, H., Liu, F., Zhang, S. and Lv, X. (2013), "Experimental investigation of concrete-filled square hollow section columns subjected to non-uniform exposure", Eng. Struct., 48, 292-312. https://doi.org/10.1016/j.engstruct.2012.09.011.
  36. Zhang, D.S. and Dong, Y.L. (2011), "Experimental behavior of one-way concrete slabs at large displacements", Appl. Mech. Mater., 105-107, 1035-1039. https://doi.org/10.4028/www.scientific.net/AMM.105-107.1035.
  37. Zhang, D.S. and Dong, Y.L. (2012), "Theoretical model for limit load-carrying capacity of one-way concrete slabs at large displacements", Adv. Inform. Sci. Serv. Sci., 4(10), 235-243. https://doi.org/10.4156/AISS.vol4.issue10.28.