CALCULATION METHOD FOR SHEAR BEHAVIOR AND SHEAR STRENGTH OF POST-TENSIONED GROUTING CONNECTION OF BEAM-TO-COLUMN JOINT IN PRECAST PRESTRESSED CONCRETE FRAME STRUCTURES

The shear behavior of post-tensioned grouting connections is important to ensure the overall performance of precast prestressed concrete frame structures. In order to study the influence of the prestress and the beam end bending moment on the shear behavior of post-tensioned grouting connections, shear tests were carried out on eleven specimens with three specimens subjected to specific bending moment. The results show that the post-tensioning can significantly increase the shear strength of the connection, and the prestress distribution influences the shear strength. The ultimate shear strength and the residual shear strength increase linearly when the prestress of the connection is uniformly distributed. When the prestress of the connection is eccentrically distributed, the greater the eccentricity of the resultant prestressing force, the greater the reduction in the ultimate shear strength of the connection. When the post-tensioned grouting connection is subjected to the beam end bending moment, the bending moment increases the compressive resultant force of the cross-section, thereby improving the shear bearing capacity of the connection before cracking. As the bending moment increases, the eccentricity of the compression resultant force increases, and the shear strength of the connection decreases after cracking, especially when the connection is in the bending limit state and the shear strength decreases to the minimum. The calculation method of the shear strength of the connection considering the effect of the prestress and the beam end bending moment was proposed.