The Structural Behaviour of Composite Beams with Prefabricated Reinforced Concrete Plate (In Zone Positive Moment)

Abstract

The beam which is taken up in this study is composed of a prefabricated reinforced concrete plate in dimensions of 3000.800.100 mm and a steel profile (INP 120) under thebeam. The steel reinforcement which should exist in the positive moment zone of the prefabricated reinforced concrete plate is replaced in while the plate has been prepared. Epoxyresin is used to provide the connection of the prefabricated concrete plate and the steel profile.The sliding and the lifting forces between the prefabricated reinforced concrete plate and thesteel profile are reacted by the agglutination property of the epoxy resin.The composite beams which are composed of reinforced concrete floor plate and steelbeams or bridge floor and steel beams are more economical than the steel beams that carries reinforced concrete plate freely on its own because in a composite beam the tensile component of the force pair, which is due to bending, is carried by the steel profile and the compressive component that is also due to bending is carried by either reinforced plate or a ofthe reinforced concrete plate and steel profile cooperation system. So, the steel profile gets ridof carrying the compressive component of bending either completely or partially. In this way,the reinforced concrete plate carrying the dead load turns out to be a useful element which carries the compressive component, and in this cooperation, the lever arm of the force pairbecome greater, so a good economical factor is constituted by this situation.The composite beams are always lighter than the reinforced concrete beams. In the composite beam, less steel is used than the reinforced concrete beam which has the sameheight. In the composite beams, a combination material called epoxy resin is used to provide the cooperation between the prefabricated reinforced concrete plate and the steel profile.During the cooperation between the concrete and the steel profile, the sliding and the lifting forces between the two materials are reacted by the help of the epoxy resin.There are not more researches about this subject (Especially, about the composite beamswhich consist of the reinforced concrete plate and the steel profile combined by the epoxyresin in the positive moment zone). Generally in the studies with the epoxy resin, the cooperation of the steel plate and the reinforced concrete beam is researched.The main purpose of our study is to research the bearing behavior of reinforced concrete beams and steel elements in the positive moment zone, and also to research how the cooperation by means of the steel profile and plates existing in the reinforced concrete beam (Agglutinated with epoxy resin) is materialized (Sliding and separation of epoxy resin fromthe steel etc.)The results which are obtained in this experimental study are in accordance with theresults of the theoretical computations that have been done. This study is about the cooperation of the prefabricated reinforced concrete plate and the steel profile. The effect ofthe concrete quality variation on the bearing strength is researched, and certain suggestionsare given.In this study, the composite beam, which is taken, is composed of a prefabricatedreinforced concrete plate in dimensions of 3000.800.100 mm and a steel profile. There inforced concrete plate that forms the compressive head piece of the composite beam will be connected with the steel profile later.While the composite beam has been prepared, the various elements which provide the connection of the prefabricated reinforced concrete plate and the steel profile are located inthe concrete during the production of the reinforced concrete plate. These elements that are located in the prefabricated reinforced concrete plate provide the connection of the reinforced concrete plate and the steel profile. The connection elements composed of U80 profile areused as the steel which provides the connection of the prefabricated reinforced concrete plateand the steel profile.These connection elements are obtained by welding the UNP 80 profile to the steel platein dimensions of 250.200.5 mm on its four sides and it is located in certain distances when theprefabricated reinforced concrete plate has been prepared by pouring concrete into the molt(Fig.2). The interconnection elements in the prefabricated reinforced concrete are combined to the steel profile by the help of the epoxy resin, and so the composite beam is achieved.