The Influence Of Steel Fiber Volume Fraction And Stirrup Ratio On Shear Behavior Of Reinforced Concrete T-beams

With the rapid development of domestic infrastructure projects,super high-rise and large scale engineering also have higher and more intensive reinforcement requirements.Accordingly,has caused many construction inconvenience and quality problems.In order to solve this problem,experts at home and abroad have carried out a large number of tests on steel fiber concrete beams,but there are few studies on the shear of high-strength reinforced steel-fiber concrete beams.In this paper,16 steel fiber high-strength reinforced concrete beams were tested and studied under static load.The influence of volume ratio of steel fiber and low stirrup ratio on shear resistance of T beam with high strength reinforced concrete is analyzed.Main contents include:1.A large number of tests have been carried out on the mix ratio of C50 steel fiber concrete,so as to reach the optimal ratio and ensure good fluidity of concrete,so as to facilitate the use of external vibrator in the later stage.2.The crack development and failure process of the inclined section of the test beam are analyzed.The steel fiber has remarkable crack resistance,which can improve the crack distribution,alleviate the high brittleness of concrete,avoid the premature stress concentration of the structure,and improve the safety of the structure.3.The influence of the main parameters on the shear performance of the test beam was analyzed by the load-deflection curve,the load-stirrup strain curve,the load-concrete strain curve,and the load-crack width curve.There is a certain combination effect between the volume ratio and stirrup ratio of steel fiber.4.According to the shear failure test results of the test beam,combined with the failure mechanism of the inclined section,the ultimate strength formula of the inclined section is deduced.The formula can be applied to steel fiber concrete beams with web height from 300mm to 700mm,According to the crack width formula of ordinary concrete,the influence of steel fiber on stirrup strain is analyzed,and the crack width formula of steel fiber concrete is deduced,which is in good agreement with the measured value.