Civil Engineering Association

This design guide has been prepared following extensive research into the behaviour of composite steel framed buildings in fire. It contains procedures and recommendations which will allow buildings to be constructed with a large number of floor beams unprotected. Columns are always required to have protection. In all cases, the fire is assumed to be a real or natural fire that might occur in a building, and not the standard fire, used for fire resistance testing, which building regulations are based on. This publication is in 10 chapters. Following the introduction, Chapters 2, 3 and 4 contain general information on how real fires were modelled and how finite element techniques might be used. Chapters 5, 6, 7 , 8 and 9 contain design recommendations. Chapter 10 contains references.
In detail:
Chapter 2 contains information on the methods used to model the real fire behaviour.
Chapter 3 contains guidance on the thermal response modelling of composite structures in fire.
Chapter 4 contains guidance on the use of finite element modelling of composite structures in fire
Chapter 5 contains general recommendations relating to building stability and compartmentation.
Chapter 6 contains design procedures and guidance on available options.
Chapter 7 contains design procedures and recommendations based on advanced FE modelling.
Chapter 8 contains design recommendations using a more conservative simple analysis method developed by the Building Research Establishment in UK.
Chapter 9 contains design recommendations based on the direct application of the simple analysis techniques of EC4-1-2.
The Guide contains, in Chapter 6, general guidance on the best procedure that should be adopted in using the tools described in Chapters 2, 3 and 4. The effects of the main parameters for the structural behaviour of composite steel framed building exposed to natural fires are quantitatively discussed on the basis of the parametric study, performed in the scope of the present research. For details, reference is made to the final project report. Alternative methods, using more conservative tools are introduced. They are further explained and quantified in Chapters 8 and 9. The recommendations in Chapter 8 are based on a much simpler structural model than a full finite element model and are therefore more conservative. The advantage of the method used is that it is more easily adapted to different building geometries and hence the method can be used in situations where no information is available from the finite element modelling. The recommendations in Chapter 9 are based on a simple beam model. They are simple to use but are very conservative as they ignore any interaction between the beams and the floor slab. They will only be useful if the intensity of the fire is low.