Modelling the response of simply-supported two-way reinforced concrete slabs exposed to fire

The historically good performance of concrete structures in real fires, and the lack of urgent drivers for the concrete industry to support research on the fire performance of concrete structures, means that research on the full frame response of concrete buildings to fires has received much less attention than for steel-framed structures. However, a credible understanding of, and ability to model, the response of concrete structures under fire exposure is crucial to make further progress in the field of structural fire engineering, and to make best use of the flexibility enabled by performance-based fire codes. This paper presents a computational study on the structural behaviour of reinforced concrete slabs during fire tests undertaken by Zhang et al.[16]. The distribution of stresses in the slabs is discussed, as is the need for further research to better understand structural response during fire. Amongst other factors, the assumed tensile strength of the concrete is crucial to accurately predict response. The results corroborate the existing consensus that concrete slabs in real buildings can, in some cases, withstand fires for longer than expected; this is due to mobilisation of membrane actions, amongst other factors.