Failure Mechanism and Seismic Behavior of Interior Joints with Different Depth Beams

摘要

Four specimens of interior joints with different depth beams were tested under reversed cyclic loading. The experimental study was conducted that focused on the effect of hoop percentage and axial compression ratio on seismic behavior of joint specimens. Test results indicated that the first crack appeared in the minor core (determined by the shallow beam and the top column), and the final failure appeared in the large core (determined by the deeper beam and the bottom column). The critical crack load was quite nearly with the ultimate load of abnormal joints, and the seismic behavior of the specimens were not influenced by the axial compression ratio but influenced by the joint hoop percentage. With the increasing of joint hoop percentage, the shear strength of the beam-column joint subassemblage increased, the width and space of diagonal cracks became smaller than that of the control specimens. Based on the experimental study, an equivalent strut mechanism for interior joints with different depth beams was put forward, and can be served as a basis for further study on mechanical properties of reinforced concrete beam-column joint.