Experimental Study of the Seismic Behavior of an Earthquake-Damaged Reinforced Concrete Frame Structure Retrofitted with Basalt Fiber-Reinforced Polymer

Abstract

A one-bay two-story reinforced concrete (RC) frame structure with weak beam-column joints was damaged during structural vibration control testing using a shake table. A damage assessment of the structure was conducted, and the structure was repaired using epoxy injection and retrofitted using basalt fiber-reinforced polymer (BFRP) sheets and retested. A seismic retrofit design method using fiber-reinforced polymer (FRP) for low-rise frame structures was proposed on the basis of mechanical analysis of the FRP-retrofitted structural components and the failure mode concept. The effective stiffness of each story increased notably after epoxy injection and FRP retrofitting. The shake table tests of the FRP-retrofitted structure showed that the shear capacity, ductility, and hysteretic energy dissipation capacity of each story were greatly improved and that the beam-column joint failure mode was prevented and the structure experienced much less damage compared with the original structure when subjected to ground motions of the same intensity. No debonding between the FRP sheets and the joints was observed after the shake table tests.