Research On Flexural Behavior Of Prestressed Steel-Concrete Composite Beams

Steel and concrete composite structure are new structures in which the steel and the concrete are integrated by connectors to take advantage of the respective properties of tension and compression. Steel and concrete composite structure have both the advantages of steel structure and concrete structure, remarkable benefit of technology economics and society have been achieved, so it has been widely used in freeway and urban bridge construction. Despite of steel and concrete composite beams have comparatively broad research in home and abroad, but there still are not respective provisions in the Chinese design specifications till now, so these aspects have a great influence on the application of this reasonable structure system. Based on these, the research on the Flexural Capacity of Prestressed steel and concrete composite beams is presented.Based on comprehensive collection of the existing research documents home and abroad, this paper expounds the factors which influenced the flexural performance of the steel and concrete composite structure, describes the especially important part of the steel and concrete composite structure-- shear connector, which integrate the steel structure and concrete structureFor the sake of analyzing the mechanical properties of prestressed steel-concrete composite beams, the paper carry through model test research which prototyped the Xingguang linking route overpass in Inner Mongolia, study the process of the composite beams being deformed, developed and broken. Then we get the midspan load-deflection curve, the slip of interface curve and strain curve which varies with its profile height. Based on the theory of elastic analysis, we can establish the calculation formula of steel and concrete composite beams which adapt to its bear symmetrical loading; through the analysis to different phase of loading of the composite beams, we can establish the calculation of bearing capacity about composite beams; analyze composit beams rigidity which influenced by slip effect. The results of calculation and testing are consistented.Through the model load test and bear capacity analysis of prestressed steel-concrete composite beams, the paper provides data information for more studies of prestressed steel-concrete composite beams, provides reference for advanced study and theoretic analysis of flexural performance of prestressed steel-concrete composite beams, and this dissertation has the certain theoretical meaning and practical value.