TAILIEUCHUNG - Strengthening of defected beam–column joints using CFRP

This paper presents an experimental study for the structural performance of reinforced concrete (RC) exterior beam–column joints rehabilitated using carbon-fiber-reinforced polymer (CFRP). The present experimental program consists of testing 10 half-scale specimens divided into three groups covering three possible defects in addition to an adequately detailed control specimen. The considered defects include the absence of the transverse reinforcement within the joint core, insufficient bond length for the beam main reinforcement and inadequate spliced implanted column on the joint. Three different strengthening schemes were used to rehabilitate the defected beam–column joints including externally bonded CFRP strips and sheets in addition to near surface mounted (NSM) CFRP strips. The failure criteria including ultimate capacity, mode of failure, initial stiffness, ductility and the developed ultimate strain in the reinforcing steel and CFRP were considered and compared for each group for the control and the CFRPstrengthened specimens. The test results showed that the proposed CFRP strengthening configurations represented the best choice for strengthening the first two defects from the viewpoint of the studied failure criteria. On the other hand, the results of the third group showed that strengthening the joint using NSM strip technique enabled the specimen to outperform the structural performance of the control specimen while strengthening the joints using externally bonded CFRP strips and sheets failed to restore the strengthened joints capacity. | Journal of Advanced Research 2014 5 67-77 Cairo University Journal of Advanced Research ORIGINAL ARTICLE Strengthening of defected beam-column joints using CrossMark CFRP Mohamed H. Mahmoud Hamdy M. Afefy Nesreen M. Kassem Tarek M. Fawzy Structural Engineering Department Faculty of Engineering Tanta University Tanta Egypt ARTICLE INFO ABSTRACT Article history Received 15 July 2012 Received in revised form 11 November 2012 Accepted 22 November 2012 Available online 11 January 2013 Keywords Beam-column joint Carbon fiber reinforced polymer CFRP Defects Near surface mounted NSM Reinforced concrete Strengthening This paper presents an experimental study for the structural performance of reinforced concrete RC exterior beam-column joints rehabilitated using carbon-fiber-reinforced polymer CFRP . The present experimental program consists of testing 10 half-scale specimens divided into three groups covering three possible defects in addition to an adequately detailed control specimen. The considered defects include the absence of the transverse reinforcement within the joint core insufficient bond length for the beam main reinforcement and inadequate spliced implanted column on the joint. Three different strengthening schemes were used to rehabilitate the defected beam-column joints including externally bonded CFRP strips and sheets in addition to near surface mounted NSM CFRP strips. The failure criteria including ultimate capacity mode of failure initial stiffness ductility and the developed ultimate strain in the reinforcing steel and CFRP were considered and compared for each group for the control and the CFRP-strengthened specimens. The test results showed that the proposed CFRP strengthening configurations represented the best choice for strengthening the first two defects from the viewpoint of the studied failure criteria. On the other hand the results of the third group showed that strengthening the joint using NSM strip technique enabled the specimen to .

• Vật lý
• Beam–column joint
• Carbon fiber reinforced polymer
• Near surface mounted
• Reinforced concrete
• Defected beam–column joints