Predicting the response of reinforced concrete slab exposed to fire and validation with IS456 (2000) and Eurocode 2 (2004) provisions

The current provisions for fire rating of reinforced concrete slab as per Indian Standard code IS456 (2000) are based on minimum width and cover to reinforcement. The influence of various parameters is not accounted in the code provisions. This paper presents a three-dimensional nonlinear finite element analysis for evaluating the fire response of reinforced concrete slabs using the FE model. The numerical analysis results are not conservative with the specified fire rating provided in IS456 (2000) and Eurocode 2 (2004). Several two-way slabs are modeled to quantify the effect of various parameters and their influence on fire rating based on different failure criteria. The analyses show that the parameters considered in the present study have significant influence on the fire rating. The fire rating of slabs with various end restraints specified in IS456 (2000) for design calculation at ambient temperature is also evaluated.