Membrane Action of Reinforced Concrete Slabs in Fire

For RC slabs supported in 2 ways, when deflection increases, membrane stress occurs within the cross section of the slab, and as a result the load‐bearing capacity of the slab is improved due to this membrane action. In this paper, the results of load‐bearing fire test are introduced that targets a composite flooring system composed of a flat RC slab in which two‐tier reinforcements are arranged and an unprotected beam. The RC slab to which the bending collapse load based on the yield‐line theory was given sustained load‐bearing capacity even after being subjected to 3 hours and more of standard fire heating.