CYCLIC LOADING TESTS OF SUB-STANDARD RC FRAMES RETROFITTED WITH BUCKLING RESTRAINED BRACES AND ELASTIC STEEL FRAMES

Abstract

Response control retrofit of existing RC buildings with buckling restrained braces (BRBs) assures immediate occupancy performance level after severe seismic events. This method is widely used in Japan and may improve the sub-standard buildings in overseas countries with high building importance factors e.g. school buildings in Turkey. Implementation of BRBs and elastically designed closed-steel frames in seismically deficient such RC frames would provide a much better damage distribution and mitigate the possible residual displacement after an earthquake. This paper describes near full-scale displacement-controlled cyclic testing of five specimens to meet the performance requirements given by the relevant codes in Japan. Special emphasis has been placed on the composite interaction between the RC frame and added elastic frame. Experimental results including hysteretic curves, dissipated energies, crack patterns on the RC elements, and strain histories are promising for the response control retrofit of sub-standard RC buildings located in seismically vulnerable areas.