Reinforced Concrete Hollow Slab Of Thin-film Effect

Due to the boundary conditions and the geometric deformation under the ultimate load, the reinforced concrete slabs are usually subjected to membrane action. Experiments show that the limit bearing capacity of a concrete slab with restraints around the edges is much greater than the one that is defined by the conventional theory line theory. Because of the low span-depth ratio and low steel ratio of a reinforced concrete hollow slab, membrane action can considerably affect its mechanical behavior. In this paper, the membrane action in cast-in-situ reinforced concrete hollow slab is studied with the elastic-plastic theory, yield line theory and finite element analysis program separately.1) Based on the limit analysis method, the limit bearing capacity is analyzed using the conventional yield line theory; the theoretical value of the limit bearing capacity of concrete slabs considering the membrane action are studied using the rigid plastic theory.2) To conduct elastic-plastic nonlinear analysis of reinforced concrete solid one way slabs and hollow one way slabs with lateral restraints, the finite element models are established. The influences of span-depth ratio, steel ratio and lateral rigidity on the limit bearing capacity are studied. Compared with the limit bearing capacity calculated using the yield line theory, the membrane effects on the mechanical behavior and the limit bearing capacity of one way slabs are analyzed.3) To conduct elastic-plastic nonlinear analysis of reinforced concrete hollow two way slabs with lateral restraints, the finite element models are established. The influences of span-depth ratio, aspect ratio, steel ratio and lateral rigidity on the limit bearing capacity are studied. Compared with the limit bearing capacity calculated using the yield line theory, the membrane effects on the mechanical behavior and the limit bearing capacity of two way slabs are analyzed.