In the last few decades, moderate and severe earthquakes have struck different places in the world, causing severe damage to reinforced concrete structures. Retrofitting of existing structures is one of the major challenges that civil engineers are facing these days. Beam-column joints, being the lateral and vertical load resisting members in RC structures are particularly vulnerable to failures during earthquakes and hence their retrofit is often the key to successful seismic retrofit strategy. The existing reinforced concrete beamcolumn joints which were designed as per code IS 456:2000 must be strengthened since they do not meet the requirements given in the ductility code IS 13920:1993. In this paper an attempt has been made to study the behavior of reinforced concrete beam-column joints retrofitted with carbon fiber reinforced polymer (CFRP) sheets. Totally six exterior reinforced concrete beam-column joint specimens (control) were cast and tested to failure. Three specimens had reinforcement details as per code IS 456:2000. Remaining three specimens had reinforcement details as per code IS 13920:1993. Various percentages of the load carrying capacity of column was given as axial load in the column. Push and pull load was applied at the free end of the cantilever beam till failure. The failed three beam-column joint specimens had reinforcement details as per code IS 456:2000 were retrofitted by removing the concrete in the joint portion and recasting with concrete of same grade and subsequently wrapped with carbon fiber reinforced polymer sheet to strengthen the specimens. The performance of the retrofitted beamcolumn joints was compared with the control beam-column joint specimens and the results are presented in this paper.
Beam-column joint, Retrofitting, CFRP sheet
