| The wrapped steel concrete structures have the merits of steel and concrete, and the wrapped angle steels have restrictive action on the core concrete, which make the structures and members have good seismic behavior. This kide of structure has been widely studied and used in the industrial workshops especially in the main buildings of power plants, because it has the simple form, the convenient connection and flexible application, and also because it has the advantages of saving forms, self-suspended forms during the period of construction, and welding the pipelines outside to fix them during the period of service. But for a long time, most researches focus on the performance of columns and beams, while neglect the seismic behavior of column-beam joints especially the exterior joints, so the references are very scarce. The shear mechanism, failure mode, deformation capacity, bearing capacity and the reliability of the anchored angle steels of the wrapped steel concrete cast-in-site frame typical story exterior joints under the middle and high axial compression ratio (n=0.3, 0.5, 0.6) , the working performance, failure mode, and the shear capacity of top story joints under the crack moment, the hysteresis characteristic and the dissipation energy capacity of the test joints are all analysed based on the 1/4 model pseudo-static tests of five specimens of wrapped steel concrete cast-in-site frame exterior joints, which varied in axial compression ratio ,distribution of the beam angle steels and the stirrup ratio. The calculating formulas for shear strength of wrapped steel joints are proposed on the basis of comprehensive analysis of the influencing factors and the experimental data. It is shown that the formulas are in good agreement with the test results. |
