Mechanical Behavior And Experimental Study On Prestressed Concrete Filled Rectangular Steel Box Beams

As it is well known, concrete is a kind of material with high compressive strength and low tensile strength, while steel is that of considerable high tensile strength. Filling concrete into steel tube makes the concrete be restricted so that its compressive strength can be increased for several times, at the same time, as the result of the inner concrete, the disadvantages of buckling and instability of the outer steel tube can also be greatly improved. This method makes the advantages the two kinds of materials have combined, and makes each behave its excellent mechanical performance more sufficiently. Structures like this are called the "concrete filled steel tube".Concrete filled steel tube structures are used for a long time as column structures, but rarely used as beam structures. With the rapid progress in economy, the modern bridge structures demand more and more in overcrossing capacity, discharge capacity and the ability of withstanding impact loads and accidentally disastrous loads. Lots of research indicates that concrete filled steel tube structures have many prominent advantages not only in bearing capacity but also in ductibility and aseismatic ability. In consideration of the limited instance of the concrete filled steel tube beam structure in bridge engineering, the lack of research information, and the comparatively laggard calculating theory, in this thesis we are attempt to do some special studies on the mechanical behavior about the concrete filled rectangular steel box beam structures.According to the Dongping bridge, in this thesis we bring out the prestressed concrete filled rectangular steel box beam structure, which is a kind of concrete filled steel tube with rectangular section, and be pre-compressed with prestressing tendons to enhance the bearing capacity and ductility. The following engineering problems will be settled through out the static load test of the prestressed concrete filled rectangular steel box beam:1,To make sure the mechanical behavior of the prestressed concrete filled rectangular steel box beam.2,To make sure how the strain and stress distribute of the prestressed concrete filled rectangular steel box beam.3,To make sure the bearing capacity and safety of the prestressed concrete filled rectangular steel box beam.