Performance of Ultra Shallow Floor Beams (USFB) exposed to standard and natural fires

This paper investigates computationally the fire performance of a plug steel-concrete composite flooring system, partially encased ultra-shallow floor beams (USFB). The investigation behaviour USFBs exposed to standard and natural fires is crucial in determining their resistance evaluating overall contemporary construction. Although product providers usually indicate based on ΕΝ1994-1-2 procedures, response elevated temperature effects remains yet neither well documented nor clearly understood. analysis involves two different 5 m 8 span. Results show that unprotected experience severe gradients while fire, as lower flange still contrast upper steel parts cross-section which are concrete. Their rating found approximately at 40 min. Moreover, thermal developed when (slow fast burning). When protected with intumescent coatings, have shown increased they can survive full duration under realistic utilization ratios. From parametric analyses, optimized thicknesses for required coating were obtained achieve 60, 90, 120 min surviving exposures.