Study On Properties Of Prestressed Steel Reinforced Ultra-High-Strength Concrete Beams Subjected To Bending

Prestressed steel reinforced ultra-high-strength concrete beams can perform the compositive properties of ultra-high-strength concrete and post-tensioned tendons, since C100is used in prestressed reinforced concrete beam structure. This style of structure reflects the idea of high strength and low energy consumption of structural materials, furthermore, the steel can improve the ductility of prestressed ultra-high-strength concrete beams.Prestressed steel reinforced ultra-high-strength concrete structure is a new structural system, having special mechanical properties. At home and abroad, there are many research literatures in prestressed steel reinforced concrete structure, while almost no research literatures in prestressed steel reinforced ultra-high-strength concrete structure. Whether at home or abroad, the lack of design specifications makes the prestressed steel reinforced concrete structure lack of theoretical support in design and construction. So it is very necessary to do some research in mechanical properties of prestressed steel reinforced ultra-high-strength concrete beams.On the basis of the existing research, combined with the National Natural Science Foundation project-study on the mechanical behavior and calculation method of prestressed steel reinforced ultra-high-strength concrete bridge, static tests and non-linear numerical simulation on21prestressed steel reinforced ultra-high-strength concrete beams are operated. The main work is as follows:(1) On the basis of the existing study, the finite element program ANSYS is used to simulate the prestressed steel reinforced ultra-high-strength concrete beams subjected to bending under static load, and the calculated and experimental results are compared, in order to obtain comprehensive mechanical properties of prestressed steel reinforced ultra-high-strength concrete beams. The results, the cracking load, ultimate load, yield load of reinforcement and the load-displacement curve calculated from the analysis model are very close to the experimental results, which verifies the correctness of the finite element model.(2) Research and analysis are operated on the influence of the designed parameters over ultimate limit state and serviceability limit state of prestressed steel reinforced ultra-high-strength concrete beams, by comparing the load-displacement curves which have the same parameters but different levels.