Study On Shear Behavior Of Prestressed High Performance Concrete T-beam

High performance concrete is a new concept developed in the last 20 years. High performance concrete has good durability, good volume stability and high strength.With the development of economy, more and more prestressed concrete bridges appear in the highway and railway traffic. Meanwhile, due to the unreasonable shear design of the bridge, the bridge damage is unavoidable. Shear failure is brittle failure,breaking abruptly, project should be avoided as far as possible. With the rapid development of high performance concrete in recent years, a growing number of bridge engineering are using the high performance concrete, combining the advantages of high performance concrete, scholars have conducted a lot of research work, but the research on the shear behavior of prestressed concrete beam is not perfect. Combined with the key project of Hebei Provincial Department of Communications: “Research on the application of high performance concrete in the highway bridge”, this paper has carried out the experimental research of 5 prestressed high performance concrete model beams. The main works are as followings:(1) Summarizes the shear theory of the concrete beam which are higher approval at present, listed the formula for calculating the shear capacity of different national codes, and the different factors of the different specification were compared and analyzed.(2) Static loading tests were carried out on 5 high performance prestressed concrete model beams. Through the analysis of the test results, studied the shear behavior of concrete with different content of fly ash and concrete strength, the results show that the shear strength can be improved by increasing the strength of concrete and the content of fly ash.(3) The model beam was simulated by using the finite element analysis software Midas Fea, the simulation results were consistent with experimental results. By changing different parameters, and analyzes the concrete strength, stirrup spacing,shear span ratio, longitudinal reinforcement ratio’s effects on the model beam shearbearing capacity. Analysis shows that increase the strength of concrete can improve the shear capacity, with the decreasing of stirrup spacing, shear strength increases,with the shear span ratio decreases, shear strength increases, increasing the ratio of longitudinal reinforcement can increase the shear capacity.