Research On Shearing Capacity Of Concrete Beam Reinforced With Anti-symmetric Rectangular Spiral Stirrup

In concrete structures, the use of spiral stirrup can not only save a lot of man-hours andthe usage of stirrups, but also can increase the bearing capacity and the integrity of concretestructures. At present, the published literature which involves the concrete beamsreinforcement with spiral stirrup is fewer, and the mechanical characteristics of concretebeams reinforced with spiral stirrups are much less, therefore, this area needs further research.In order to get the impact of shear capacity of beams reinforced with anti-symmetricrectangular spiral stirrup under monotonic concentrated load, shear tests of12reinforcedconcrete beams is designed in this paper, including3beams reinforced with common form ofrectangular hoop, and the other9beams are configured in the form of anti-symmetricrectangular spiral stirrup. Considering many factors affect the shearing capacity of concretebeam, the test program designed in this paper preferred three factors: strength grade ofconcrete (C20, C25, C30), stirrup spacing (100mm,150mm,200mm), shear span ratio (1.51,2.03,2.5). Considering the influence of variation of the three levels of the three factors onshearing capacity of inclined section of concrete beam, the test of9anti-symmetricrectangular spiral stirrup beams are designed in L9（34）orthogonal table.In this paper, the failure processes of the test beam were described, deflection curve,shear span shear--stirrup strain curve of the test beam were given. This paper use rangeanalysis method and variance analysis method to analyze the test results, at the same time，comparative analysis the anti-symmetric rectangular spiral stirrup beams and3referencebeams. The results show that, the use of anti-symmetric rectangular spirals enhanced shearcapacity of the beam, the anti-symmetric form rectangular spiral hoop reflects the bettershearing capacity to the vertical stirrups in the shear test. Based on the experimental data, thispaper preliminary explores the impact of shearing of capacity of concrete beam reinforcedwith anti-symmetric form rectangular spiral stirrups.Finally, based on the analysis of the test results, and according to the form of calculationformula of shear capacity of inclined section in Chinese code、the United States code、Europecode and British standard, combined with MATLAB software, gives the calculation formulaof shearing capacity of concrete beam reinforced with anti-symmetric cross section formrectangular spiral hoop.