Application of X-Shaped CFRP Ropes for Structural Upgrading of Reinforced Concrete Beam–Column Joints under Cyclic Loading–Experimental Study

The effectiveness of externally applied fiber-reinforced polymer (FRP) ropes made carbon fibers in X-shape formation and both sides the joint area reinforced concrete (RC) beam–column connections is experimentally investigated. Six full-scale exterior RC specimens are tested under reverse cyclic deformation. Three them have been strengthened using FRP (CFRP) that placed diagonally as additional, near surface-mounted reinforcements against shear. Full hysteretic curves, maximum load capacity, damage modes, stiffness energy dissipation values per each loading step presented compared. Test results indicated sub assemblages with X-shaped CFRP exhibited improved behavior ameliorated performance respect to reference specimens. easy-to-apply character strengthening technique also discussed.