Experimental evaluation of composite floor assemblies under fire loading

This paper presents the results of experimental investigations on the structural behavior of composite beam and floor systems subjected to gravity and thermal loading through experimental testing. Two specimens were tested, each 3.96 m by 4.57 m in plan with single plate, beam-to-girder shear connections. Specimens were tested under design and realistic fires and with and without fire-protection on the interior beams. The results show that the removal of fire-proofing caused the composite beam section to: (i) heat more rapidly; (ii) follow the furnace time-temperature curve closely; (iii) have increased deflections at the beam mid-span; and (iv) only nominally affect the temperatures in the girders and connections. The replacement of the design fire conditions with realistic fire conditions caused slower cooling of all elements in the system and increased permanent deformations in the beam and girders.