Experimental Study Of Bending And Seismic Performance On Partially Steel-encased Prestressed Composite Beams

Partially encased-steel prestressed composite beam welded the shear connector in upper or lower flange and penetrated the non-coherent PC stranded wire from sternum's both sides of the hot-rolling H beam steel,installed anchorage,pour concrete,cured 28 days is a a new type of prestressed concrete encased composite beam which is used post-tension construction.This new type of composite beam incorporated the advantages of the common steel-concrete composite beam's large span,good corrosion resistance,light weight,high rigidity,lose its stability difficultly,small cross-sectional area and prestressed technology satisfies the requirements of architectural structual diversified types in modern society.The flexural and seismic performance of a new type of prestressed composite beams is studied by the hydraulic jack and MTS electro-hydraulic servo loading system in this paper to analysis the basic mechanical properties and seismic performance under static and pseudo-static.The main research works are as follows:First,the dissertation based on the Guangxi fund of natural science “steel partially encased prestressed concrete beam of basic mechanical properties and seismic performance study”,the 8 partially encased-steel prestressed composite beams are grouped into 2 sets equally,the flexural and seismic performance have been investigated by the experiment.This paper describes the design of two experiments,production,material properties,loading program and testing contents,through observation of the phenomenon,We conduct a comprehensive analysis of it's performance including the development status of the cracks,the relation of stress-strain curve and load displacement curve which was obtained from the test data.Second,We put forward a series of calculation methods about the prestressing loss throughout the stress process,the crack resistance and the anti-bending bearing capacity that based on experimental research on the flexural performance of partially encased-steel prestressed composite beam,at the same time,We put forward it's maximum crack width and mid-span deformation calculation formula,which are compared with experimental results,according to the crack width development and the changes of the deflection.Third,We put forward the calculation method of the prestressing loss and cracking load of each test beam,though the experimental research on the seismic performance of partially encased-steel prestressed composite beam,also,it is obtained the hysteretic curves,skeleton curves,stiffness degradation curves from analysising on the experimental data.According to the test beams' deformation under low reversed cyclic loading and the area of hysteresis curves,we can get the aseismatic performance including the characteristics of loads of each test beam,ductility and deformation capacity,deformation recovering ability,energy dissipation capacity.