Experimental Study On Direct Shear Behavior Of New Precast Concrete Joints With Different Structural Measures

As one of the structural components with high degree of standardization,high degree of digital modeling and high added value of technology,the fabricated structure is an important direction for the future development of China's construction industry.Precast concrete shear wall structure as an important part of the fabricated structure,The connection technology between prefabricated units is the key to restricting the structure of precast concrete shear wall.The connection technology with high degree of industrialization and excellent overall performance meets the needs of China's current construction industry.This paper proposes a new type of precast concrete shear wall structure connection:Horizontal grooves on both sides of precast concrete wall panels,Then connect the different prefabricated units into a force-bearing whole by pouring concrete at the groove position.This connection is uniquely constructed and the seam location is the key to the overall performance of the structure.This paper designs a reference test piece and three different types of joint construction parameters change test pieces.The direct shear tests of four specimens were carried out,and the effects of shear wall properties on shear wall joints under different vertical hole width,joint width and groove depth construction parameters were studied.The results show:(1)From the comparison of performance indexes such as shear bearing capacity,bearing capacity-displacement curve,joint joint opening deformation and joint strain curve of each test piece: Increasing the vertical hole width increases the joint's resistance to deformation;increasing the joint width reduces the shear capacity of the test piece,delays the initial cracking of the test piece,and significantly reduces the vertical shear displacement during cracking;The large and new concrete bite force in the groove position significantly increases the cracking load,and the vertical shear displacement decreases significantly.(2)From the comparison of the shear bearing capacity,bearing capacity-displacement curve and joint opening deformation of each test piece,the increase of vertical hole width reduces the shear capacity of the test piece and delays the initial test piece.Cracking has little effect on the deformation at the seam;reducing the width of the joint has less influence on the shear bearing capacity of the specimen,and the joint opening deformation is obviously increased.(3)The finite element numerical simulation analysis of four specimens was completed by Abaqus software.The calculated results obtained the bearing capacity-displacement curve and the maximum plastic strain cloud map are in good agreement with the experimental phenomena.It can be used as a reference for subsequent research on new shear wall structures.