Verulam

A companion paper gives details of a new method for the design of steel framed structures, with composite floorslabs, subject to fire. This method is based on the fire tests carried out on the full-scale steel framed building at Cardington. Observations from these tests confirmed the general view that the performance of composite flooring systems is under-utilised in current design procedures for the fire limit state. This is due to the development of in-plane forces in the floorslab at large displacements, which enhance the slab’s loadcarrying capacity. C.G. Bailey and D.B. Moore

This paper presents the development of a new design method for calculating the performance of steel framed buildings, with composite flooring systems, subject to fire. This design method is based on the results from a series of full-scale fire tests an eight-storey steel framed building, together with associated theoretical and further experimental investigations. The results from this work show that the performance of composite steel deck flooring systems in fire is under-utilised in current design procedures. This is owing mainly to the ability of lightly reinforced composite slabs to bridge over the supporting fire-damaged steel beams and transfer load, using membrane action, to the undamaged parts of the steel structure. From these observations a simple design method is developed that is based on a holistic, rather than an elemental, approach. This allows the various interactions between the components of a composite slab, supported by a grillage of steel beams, to be taken into account, producing cheaper and more innovative, site-specific, fire-engineering solutions. A companion paper shows how this design method can be applied to practical buildings. C.G. Bailey and D.B. Moore

Not the most glamorous of subjects - no teflon-coated fabric, wires and FE analysis here, but it is more than likely that, during the course of their career, most structural engineers will be responsible for a concrete ground slab for a warehouse, distribution facility, retail store or similar. Frank Neil