ON REHABILITATED RC FRAME USING HYSTERETIC DAMPER INSTALLED IN BEAM LOWER SPACE

We proposed the new rehabilitation technique of RC frame using hysteretic damper installed in beam lower space. A short steel lever is attached in the middle of beam. Two hysteretic dampers are installed between a steel lever and RC column. Hysteretic damper consists of notched steel strip and channel stiffener to prevent the buckling. It is so called buckling constrained brace. Two methods of connection between hysteretic damper and RC column are proposed. One is tension-bolt-type connection and the other is compression-plate-type connection with wedge device. To show the availability of the present rehabilitation technique, cyclic loading tests on scaled RC frame with hysteretic damper were performed. Results and conclusions obtained from loading tests are summarized as follows. 1) Damper yields within small story drift, so that the system absorbs the seismic energy effectively. 2) There is no significant difference in total absorbed energy between tension-bolt-type connection and compression-plate-type one.