Modelling the Response of Simply-Supported Two-Way Reinforced Concrete Slabs Exposed to Fire

Abstract:

The historically good performance of concrete structures in real fires, and the lack of urgent drivers for the concrete industry to support research on the fire performance of concrete structures, means that research on the full frame response of concrete buildings to fires has received much less attention than for steel-framed structures. However, a credible understanding of, and ability to model, the response of concrete structures under fire exposure is crucial to make further progress in the field of structural fire engineering, and to make best use of the flexibility enabled by performance-based fire codes. This paper presents a computational study on the structural behaviour of reinforced concrete slabs during fire tests undertaken by Zhang et al.[16]. The distribution of stresses in the slabs is discussed, as is the need for further research to better understand structural response during fire. Amongst other factors, the assumed tensile strength of the concrete is crucial to accurately predict response. The results corroborate the existing consensus that concrete slabs in real buildings can, in some cases, withstand fires for longer than expected; this is due to mobilisation of membrane actions, amongst other factors.

• Periodical: Key Engineering Materials (Volume 711)
• Pages: 588-595
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.711.588
• Online since: September 2016
• Authors: Emran Baharudin*, Luke Bisby, Tim Stratford
• Keywords: Finite Element Modelling (FEM), Fire Tests, Performance-Based Design, Reinforced Concrete Slabs

References

[1] ASCE, Structural fire protection, American Society of Civil Engineers, New York, USA, (1992).

[2] ASTM, Standard methods of fire tests of building constructions and materials, (1985).

[3] C. Bailey, Holistic behaviour of concrete buildings in fire, in: Proc. ICE - Struct. Build., 2002: p.199–212.

[4] C. Bailey, W.S. Toh, Small-scale concrete slab tests at ambient and elevated temperatures, Eng. Struct. 29 (2007) 2775–2791.

DOI: 10.1016/j.engstruct.2007.01.023

[5] CEB-FIP, CEB-FIP Model code 2010 Volume 1, Lausanne, (2010).

[6] CEN, Eurocode 2 : Design of Concrete Structures - Part 1-2: General rules - Structural fire design, Brussels, (2004).

[7] E. Ellobody, C. Bailey, Modelling of unbonded post-tensioned concrete slabs under fire conditions, Fire Saf. J. 44 (2009) 159–167.

DOI: 10.1016/j.firesaf.2008.05.007

[8] T. Gernay, A multiaxial constitutive model for concrete in the fire situation including transient creep and cooling down phases, University of Liege, (2012).

[9] Z. Huang, The behaviour of reinforced concrete slabs in fire, Fire Saf. J. 45 (2010) 271–282.

DOI: 10.1016/j.firesaf.2010.05.001

[10] Z. Huang, I.W. Burgess, R.J. Plank, Modeling Membrane Action of Concrete Slabs in Composite Buildings in Fire. II: Validations, J. Struct. Eng. 129 (2003) 1103–1112.

DOI: 10.1061/(asce)0733-9445(2003)129:8(1103)

[11] ISO, ISO 834-1: Fire resistance tests - Elements of building construction - Part 1: General requirements, (1999).

[12] L. Lim, A. Buchanan, P. Moss, J. -M. Franssen, Numerical modelling of two-way reinforced concrete slabs in fire, Eng. Struct. 26 (2004) 1081–1091.

DOI: 10.1016/j.engstruct.2004.03.009

[13] L. Lim, C. Wade, Experimental Fire Tests of Two-Way Concrete Slabs, Christchurch, New Zealand, (2002).

[14] T.D. Lin, R.I. Zwiers, S.T. Shirley, R.G. Burg, Fire test of concrete slab reinforced with epoxy-coated bars, ACI Struct. J. 86 (1989).

DOI: 10.14359/2652

[15] Y. Wang, Y.L. Dong, G.C. Zhou, Nonlinear numerical modeling of two-way reinforced concrete slabs subjected to fire, Comput. Struct. 119 (2013) 23–36.

DOI: 10.1016/j.compstruc.2012.12.029

[16] D. Zhang, Y. Dong, Y. Fang, Behaviour of full-scale two-way simply supported concrete slabs in fire, Mag. Concr. Res. 66 (2014) 836–844.

DOI: 10.1680/macr.13.00352