Pushover tests on steel X-braced and knee-braced RC frames

Results of pushover experiments conducted on scaled models of ductile RC frames, directly braced by steel X and knee braces are presented. Test results indicate that the yield capacity and the strength capacity of a ductile RC frame can be increased and its global displacements can be decreased to the desired levels by directly adding either an X- or a knee-bracing system to the frame. X bracing can provide a stiffer bracing system but reduces the ductility of the ductile frame. Knee bracing can be employed to provide the desired ductility level for a ductile design. It is concluded that both X-bracing and knee-bracing systems may be used to design or retrofit for a damage-level earthquake. However, when designing or retrofitting for a collapse-level earthquake, knee bracing is a more effective system.