REINFORCED-CONCRETE MEMBRANE ELEMENTS WITH PERFORATIONS

An experimental investigation is described in which perforated reinforced concrete panel elements were subjected to uniformly distributed, monotonically increasing edge loads. Test parameters included the presence of a perforation, detailing of the reinforcement, and type of load condition. It was found that the stress disturbances created by a perforation resulted in significant reductions in element strength and stiffness and localized damage near the opening. The addition of extra reinforcement around the opening partially alleviated this influence. Predictions of panel response were made from nonlinear finite element analyses, using a formulation based on the modified compression field theory. Good accuracy was obtained in the predicted crack patterns, load-deformation responses, reinforcement stresses, ultimate loads, and failure modes. The results suggest that behavior models based on a smeared, rotating crack can adequately represent response under locally complex stress conditions, provided proper consideration is given to concrete compression strain-softening effects and tension-stiffening effects. © ASCE.