EXPERIMENTAL RESEARCH ON SEISMIC BEHAVIOR OF EXTERIOR JOINTS OF SPECIALLY SHAPED COLUMNS WITH X-SHAPED REINFORCEMENT

The exterior joint of specially shaped columns with or without X-shaped reinforcement was tested under low cyclic loading. The damage characteristic, hysteretic curve, bearing capacity, displacement, ductility and energy dissipation were compared. The change of the stirrup strain of the core of joint was studied. The cumulated damage was analyzed using the damage accumulation model at last. It is shown that the hysteretic behavior of the joint with X-shaped reinforcement is improved significantly, the ductility is enhanced and the degree of cumulated damage is relieved. Therefore, the overall seismic behaviour of specially shaped column joints with X-shaped reinforcement is improved significantly.