Title: Shake-Table Testing of Deficient Reinforced Concrete Frame Retrofitted with Buckling Restrained Brace
Author(s): M. M. Rafi, S. H. Lodi, Z. A. Al-Sadoon, M. Saatcioglu, and D. Palermo
Publication: Structural Journal
Appears on pages(s): 161-173
Keywords: buckling restrained brace; earthquake engineering; energy absorption; hysteretic energy; reinforced concrete (RC) building frame; shake-table testing
This paper presents results of shake-table testing on a single-story
and single-bay reinforced concrete (RC) frame which was strengthened by a newly designed buckling restrained brace (BRB). The objective of strengthening by BRB was to increase the lateral strength and stiffness, and energy dissipation of the frame. A companion frame without strengthening was used as the control specimen and was tested along with the BRB-strengthened frame. Different levels of the 1995 Kobe earthquake record were employed to impose the dynamic loading on the frames up to a peak ground acceleration (PGA) of 0.679g. The implementation of the BRB increased the frame lateral stiffness, resulting in an approximately 80% reduction in the initial fundamental period of the frame. Concrete in the plastic hinge region at base of the columns in the control frame crushed at PGA = 0.679g after yielding of the longitudinal reinforcement. The BRB-strengthened frame remained within the elastic range at all stages of load application, exhibiting high lateral strength with some reduction in stiffness at 0.679g. The
lateral force sustained by the BRB-strengthened frame at PGA of 0.679g was nearly 215% higher (on average) as compared to the maximum force sustained by the control frame. The displacement ductility ratio for the control frame was 2.42.