Seismic retrofitting of full-scale RC interior beam-column-slab subassemblies with CFRP wraps

To investigate the effect of carbon fiber-reinforced polymer (CFRP) retrofitting on the failure modes and seismic performance of reinforced concrete (RC) frames, this paper presents the quasi-static test results of four full-scale interior subassemblies with slab and transverse beams. These beam-column-slab subassemblies consisted of one control specimen and three specimens with different CFRP retrofitting schemes. The seismic performance of subassemblies was discussed by comparing failure modes, hysteretic behavior, displacement ductility, stiffness degradation, energy dissipation capacity, shear deformation of joint region and beam vertical deformations. The test results demonstrated that the control specimen finally exhibited column-hinge failure mode due to the existence of slab and transverse beams. After being retrofitted with CFRP, the failure varied to ductile beam-hinge failure mode and the ductility and energy dissipation capacity were enhanced. For the interior beam-column-slab subassemblies, wrapping CFRP wraps at the potential plastic hinge region of columns is a reasonable method for improving the seismic performance and implementing the strong column-weak beam failure mode.