Flexural Behavior Of Steel-precast Concrete Composite Beams

Housing Industrialization is becoming a construction trend due to itsadvantages in construction efficiency, energy conservation and environmentalmanagement, which allows wide applications of composite structures around theworld and consequently leads to considerable social and economic benefits. As oneof the most common composite members, concrete composite beams outshinecast-in-situ concrete beams for their convenient installation, less templates demand,short construction period, low construction cost, and standard construction members.Meanwhile, they have better integrity and seismic resistance behavior in comparisonwith total precast concrete beams. Implementing precast concrete beams in steelstructure and composite structure will not only broaden the application of compositestructure, but also reduce the construction cost.The key issue of the implementation is the connection between precast concretebeams and steel columns or concrete filled steel tubes, current connection practicesare too complex and difficult for construction, which greatly inhibit thedevelopments and applications of precast structures. Therefore, it’s urgent to designconnections with easier construction and better mechanical behaviors.In this paper, experimental and numerical studies were conducted focusing onthe flexural behavior of two different kinds of steel-precast concrete compositebeams with the same connections, which were both developed on the basis of thepatent named ‘A New Kind of Precast Steel-Concrete Composite Beam’(ZL201010213908.02). The main contents were as follows:(1)Numerical simulate on steel-precast concrete beamsSection lamina method was utilized to study the cracking moment, ultimatebearing moment and the moment-curvature relationship based on MATLAB; athorough parametric analysis was conducted to investigate the influence of steelstrength, concrete strength and ratio of reinforcement on the flexural behavior of thesteel-precast concrete beams.(2)Flexural experimental research on steel-precast concrete beamsThree full-scale specimens were tested, including one cast-in-situ concretebeam and two steel-precast concrete composite beams. Displacement, vertical load,strain, the width and distribution of cracks and slippage were measured. The failuremode of the composite beams was obtained.(3)Finite element analysis and design method of steel-precast concrete beamsThree FEM models were developed using ABAQUS to analyze the flexuralbehavior of the steel-precast concrete beams. The validation of the models is demonstrated by the comparison of experimental results. Two3D frame models arebuilt to study the performance of the steel connection. Prefabrication process anddesign method were summarized based on the above experimental and numericalstudies, providing theoretical references for field applications.