Abstract
In this contribution, efficiency and effectiveness of Carbon fiber reinforced polymer (CFRF') sheets in upgrading the ductility and shear strength of seismically deficient exterior and interior beam-column joints have been studied. Four as-built joints, two exterior and two interior, were constructed with non-optimal design parameters (poor ductility and inadequate joint shear strength with no transverse reinforcement) representing pre-seismic code design construction practice of joints and encompassing the vast majority of existing beam-column connections. Out of these four as-built specimens, one exterior and one interior specimen were used as baseline specimens (control specimens) and other two (again one exterior and one interior) were strengthened with CFRP sheets. These specimens were identified as strengthened specimens. For strengthening, CFRP sheets were epoxy-bonded to joint, beams and part of the column regions. All these four sub-assemblages were subjected to cyclic lateral load histories so as to provide the equivalent of severe earthquake load. Response histories of control and strengthened specimens were then compared. The comparison shows that CFRP sheets are very effective in improving ductility and shear resistance of the exterior and interior beam-column joints.