Effect of fire induced restraint on fire resistance of reinforced concrete beams

The effect of fire induced restraint on the fire response of reinforced concrete (RC) beams is addressed in this paper. A macroscopic finite element model, capable of tracing the behavior of restrained RC beams from pre-fire stage to collapse in fire is used in the analysis. The model is applied to investigate the effect of five parameters; namely, degree of axial restraint, span-to-depth ratio, fire scenario, load level, and failure criteria on the fire response of restrained RC beams. Through the results of the parametric study, it is shown that the five parameters have significant influence on fire resistance of RC beams. It is also shown that, fire induced restraint has negative effect on fire resistance of slender RC beams having high span-to-depth ratio.