Structural Behaviour in Fire and Real Design

A great deal of understanding into the behaviour of composite steel-concrete structures in fire has been developed since the Cardington frame fire tests (UK) 1990s. This has now been broadened so that structures in fire design has a real engineering basis and is not reliant on results from single element testing in the standard furnace. Several projects involving office buildings in the UK and abroad have highlighted the need for developing the understanding of whole frame behaviour in fire. Since 9-11 robust engineering solutions where the response of the building to an event like fire is known are in great demand. The basics of structural mechanics at high temperatures can be used in design to understand many structures with the aid of computer modelling. This paper provides a direct comparison between the structural response of an 11-storey office building now constructed in the city of London, when designed in a prescriptive manner, with applied fire protection on all the load bearing steelwork, and the response of the same structure designed using a performance based approach leaving the majority of secondary steelwork unprotected. The intent is to demonstrate that structural stability during the fire limit state can be maintained in specific case