Experimental studies on strength and ductility of CFRP jacketed reinforced concrete beam-column joints

• Effect on the strength of beam-column joints retrofitted with CFRP jackets.
• Various retrofitting methods are used and bonding method is most appropriate.
• CFRP retrofitting increases the ultimate, yield load capacity and stiffness.
• The use of CFRP jacketing for retrofitting helps to regain full strength.

Beam-column joints in reinforced concrete (RC) framed structures are recognized as most vulnerable structural element subjected to lateral loads. The use of various jacketing techniques for strengthening or retrofitting the existing structural components is very frequent. In the present work, the effect on the strength of beam-column joints initially stressed to three different stress levels, retrofitted with CFRP jackets has been presented. A total of 9 RC beam-column joints were tested under static loading conditions. CFRP strengthening has been carried out for beam-column joints already stressed to three different stress levels. The jackets have been provided in L-shape and at 45° orientation to the joint in two layers. The results show improvement in the ultimate load carrying capacity (7–12%) of the retrofitted beams, when compared to the control beams along with an increase of 15% in yield load for each of such exterior beam- column joints. Stiffness up to the first crack load was 17.36% and 26.94% more for stress level-2 and stress level-3 as compared to stress level-1.