Analytical assessment of the structural performance of composite floors subject to compartment fires

The behaviour of composite steel-concrete building floors exposed to fire c onditions is examined in this paper. The work represents part of a large pr oject dealing with the numerical modelling and assessment of structural beh aviour based on the fire experiments undertaken on a full-scale multi-store y steel-framed building at Cardington, UK. After providing brief details on the analytical tools and modelling approaches adopted in this investigatio n, the structural models constructed to simulate the fire tests are describ ed and salient findings are highlighted. Although the detailed models provi de some insight into key behavioural aspects such as the paramount influenc e of restraint to thermal expansion, the complex structural interactions th at occur under fire conditions may not be readily demonstrated. In order to illustrate a number of underlying response mechanisms, the analytical resu lts obtained from an idealised structural system, in which a single compart ment is subjected to fire, are summarised. Assessment of the structural res ponse using such simplified models provides a clear interpretation of the b ehaviour and, with further refinements, may be employed for undertaking det ailed studies aimed at developing improved design recommendations. (C) 2001 Elsevier Science Ltd. All rights reserved.