Research On Shear Behavior Of Steel Reinforced High Ductile Concrete Deep Beams

Steel reinforced concrete(SRC)transfer beam is commonly used in the transfer layer of elevated station and high-rise building.The common span to depth ratio is small,which belongs to the field of deep beam.It is extremely easy to occur brittle shear failure under shear load.In order to improve the brittle shear failure mode of SRC deep beams,propose and research on the shear behavior of steel reinforced HDC(SRD)deep beams.In this paper,the deformation behavior and shear bearing capacity of the SRD deep beams are analyzed,and the evaluation method of flexural toughness of HDC is proposed.The main research contents are as follows:(1)The flexural toughness evaluation index and its influencing factors were studied through bending test of 9 groups of different mixture ratio HDC specimens,then presente the evaluation index and calculation method of flexural toughness of HDC.Analysis results show that the equivalent flexural toughness index can effectively reflect the HDC energy absorption ability of unit volume plastic district,which can be as HDC flexural toughness evaluation index.(2)Based on the test results of shear performance of 6 SRC or SRD deep beams,the deformation calculation method of SRC deep beam deformation is presented,considering the shear deformation of SRC deep beam is larger after shear crack.The results show that the calculation results agree well with the measured deformation.(3)Based on experimental study on shear performance of 66 SRC beams in related literature,accordance to the crack development and failure mode of SRC deep beams,the modified strut-and-tie model(STM)of SRC deep beams was established,the steel in the model was reasonably simplified,the calculating formula of shear bearing capacity is deserved on the basis of modified strut-and-tie model.(4)Based on the experimental study of shear performanceof 2 SRC and SRD transfer beams,the calculating formula of shear bearing capacity of SRC(SRD)transfer beams is deserved on the basis of modified strut-and-tie model.The results show that calculation results of the modified STM agree well with the experimental data,it can be used for the calculation of shear capacity of SRC continuous deep beam.