Flexural response of reinforced concrete beams exposed to fire

V. Kodur, Michigan State University, USA
M. Dwaikat, Michigan State University, USA 

The flexural response of reinforced concrete (RC) beams exposed to fire is investigated in this paper. A macroscopic finite element model, capable of tracing the behaviour of RC beams from pre-fire stage to collapse in fire is used in the analysis. The model includes the three stages associated with fire resistance analysis, namely establishing the fire temperature - time development, calculating the heat transfer through the structure from fire and the structural analysis. The model is applied to investigate the effect of six parameters, namely the fire scenario, load level, concrete cover thickness, aggregate type, failures criteria and span length on the fire response of RC beams. Through the results of the parametric study, it is shown that the type of failure criterion, load level, fire scenario, concrete cover thickness and aggregate type have significant influence on fire resistance of RC beams. It is also shown that, while the span length has significant influence on the overall fire behaviour, it has a minor effect on the fire resistance of RC beams.