THE INFLUENCES OF JOINT ON THE PROGRESSIVE COLLAPSE-RESISTING PERFORMANCE OF RC FRAMES

The influence of structural joints on the progressive collapse-resisting capability of reinforced concrete (RC) frames is studied by employing the structure designed in accordance with Chinese building codes. The comparison of the two numerical models with and without joints indicates that the influences of the joint have a significant effect of increasing the structural displacement responses while decreasing the structural progressive collapse-resisting capability on the progressive collapse-resisting performance of the structure. It is confirmed through the parametric analyses that the diameter and strength of the steel bars have great influences while the joint shear deformation and the concrete compressive strength in joint region have little influence on the progressive collapse-resisting capability of the structure. In addition, the analysis of failure modes of members considering the influence of joints shown that the flexural failure mode remains a dominant failure mode of the members, and no members appear shear failure. The conclusions can be used as references for the progressive collapse-resisting design and strengthening of RC frames.