Sustainable Frames for Seismic Resistance to Captive Column Defects

Reinforced concrete constructions with partial masonry infill face serious earthquake shear damages in columns due to captive-column effect. An experimental program is carried out with one-third scale, two-bay two-story laboratory models having partial infill in the bottom story. Glass-fibre reinforced polymer sheets are wrapped around the columns at critical points for adequate ductility. Two frames namely, a control specimen and a retrofitted specimen are tested under quasi-static cyclic load to failure. The control specimen showed a brittle shear failure in the bottom story columns due to the induced captive-column effect while the retrofitted specimen showed a more ductile failure without any brittle damages. Results demonstrated the behavior with respect to strength and stiffness characteristics. The aim is, therefore to contribute for developing a sustainable structure to overcome the seismic failure due to captive-column defects.