Fire resistance of composite steel & concrete highway bridges

In this paper, the effects of geometric skewness and abutment restraint on the fire resistance of a real highway bridge have been studied. Four finite element models have been investigated using rectangular and skew shapes with and without modelling the abutment. The investigation has been carried out in three steps: 1) heat transfer analysis under a specified hydrocarbon fire; 2) simulation of the thermo-mechanical response of the bridge superstructure over the entire duration of the fire using beam and shell elements to represent the structural components; 3) detailed processing and interpretation of the simulation results to understand and illustrate the global response of the structure by comparing all the models. Results indicate that a skew bridge may possess greater inherent resistance to fire. For the two-span highway bridge model, restraint from the abutment does not affect the estimated failure time significantly.