An experimental study for the thermal behavior of composite concrete beam with slab compared with isolated beam under fire

Abstract

As the number of fire accidents is gradually increasing, many experimental studies on fire performance of concrete have been reported by focusing on thermal behaviors of isolated structural members under fire. However, experimental approaches still have issues due to experimental conditions, such as heating and loading limits. One of them is about using isolated specimens for experiments, because when structural member is solely tested under fire, the behaviors may be different from those of structural members connected to each other. It is worth verifying whether isolated beam shows different behaviors under fire compared to the case with beam-slab connections, considering most structural members are connected to each other in real buildings. With these considerations, this paper aims at evaluating thermal behaviors between isolated specimen and composite specimen from experiments. Toward that goal, fire tests are performed on concrete beams connected with slab and isolated beams by applying high temperatures according to ISO-834 standard time-temperature curve. This study uses two different parameters; the first is fire exposure time and the second is whether it is joint with other structural members. From the experiments, time-temperature curves are obtained at several locations and differences of thermal behaviors between beam with slab and isolated beam are compared to each other.