Seismic performance of steel braces jointed with high performance fiber reinforced cementitious composites and steel bars

Steel-braced frames have been widely used for retrofitting due to their effectiveness in terms of their light weight and short construction period. The steel-braced frame retrofitting method is difficult to apply, however, to the inner frames of buildings. Consequently, there has been a demand for a braced frame retrofitting method that can be broadly and easily applied to both the inner and outer frames of buildings. In this study, a retrofitting method using steel-braced frames with HPFRCC and steel bars is proposed. The pre-fabricated upper and lower segments of the brace member are connected on-site with HPFRCC, meaning that the proposed method is applicable to the inner frames of buildings as a seismic retrofitting method that has the advantage of simple and rapid installation. The tension force is transmitted only through the steel bars, which transmit the compression force to the HPFRCC of the joint that connects the three brace units. The results of cyclic tests of four specimens clearly showed that steel braces using HPFRCC and steel bars ensure stable structural performances and improve construction efficiency.