Experimentalon Seismic Behavior Of Specially Shaped Columns Joints Reinforced By Steelor Fiber Reinforcement

The reinforcement concrete structure with specially shaped column, which continuesthe advantages of frame structure, gradually replaces the traditional rectangular column andforms a new Architecture. But because of its larger ratio of column height and width, jointsbecame the weak parts of the specially shaped column structure. To solve this problem,steel reinforcement or fiber reinforcement to the weak part of joints with specially shapedcolumns is proposed and investigated. The experiment and research foundation wereprovided for this structure, which is better to generalize further.Five exterior joints and four interior joints were tested under low cyclic loading. Thebearing capacity, displacement, ductility, hysteretic curve, rigidity degradation, andenergy dissipation were analyzed. Compared steel reinforcement or fiber reinforcementjoints with normal joints, several conclusions are got. Steel reinforcement or fiberreinforcement is an effective measure to reduce crack width, to improve the ability ofdeformation capacity and bearing capacity, to defer the rigidity degradation and improvethe energy dissipation. The test results show that the bearing capacity and seismicperformance of Steel reinforcement or fiber reinforcement joints are better than normaljoints,so it can be popularized in the future.Through analyzing the existing damage models, the cumulative damage model whichis based on energy dissipation and P-△hysteresis characteristics is selected to calculate theaccumulation damage index. Compared steel reinforcement or fiber reinforcement jointswith normal joints, the accumulation damage index of reinforcement joints are smaller thannormal joints. The result shows that steel reinforcement or fiber reinforcement is benefit toseismic performance. Moreover stress mechanism of specially shaped column structurejoints was analyzed to explain the feasibility in theory.