Cyclic performance of exterior R.C beam-column strengthened with different thicknesses of CFRP sheets

Abstract

The recent ground motion results indicated that the RC buildings are required to be retrofitted by different strengthening techniques. Nowadays, the external strengthening gain interest since its easy, cost effective and not required redesign of buildings. The CFRP sheets are suitable solution and utilized by a number of researchers. However, the numerical cyclic performance of connection strengthened with different thicknesses of CFRP need to be well investigated. This study assessed the performance of RC exterior beam column connection strengthened with CFRP sheets First, two grades of concrete are utilized to be control specimens, normal concrete compressive strength (C20) and high concrete compressive strength (C50) then, the specimens are retrofitted with different thicknesses (1.2, 2.4, 3.6mm) of CFRP sheets. The stresses and damage states showed the importance of connection retrofitting. The CFRP shift the plastic hinge zone away from the panel zone. Furthermore, the results demonstrated that by increase of CFRP thickness the connection resistance will be improved. The comparison between the hysteresis curves demonstrated that the yield and ultimate loading were enhanced for strengthened connection for both concrete grades and the incremental in thicknesses also increase them. The outputs also exhibited that the stiffness and ductility has increased for retrofitted specimens indicating that the CFRP comprehensively overcome the applied cyclic loading and the beam column connection is able to resist such type of loading.

Seismic Tests of Full Scale Reinforced Concrete T Joints with Light External Continuous Composite Rope Strengthening—Joint Deterioration and Failure Assessment

“…Externally-bonded composite materials have been extensively used in different configurations in strengthening of RC columns and beams as well as in joints [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. FRPs, or even SRPs [ 17 ], have been used as a lightweight, flexible and corrosion-resistant local retrofitting alternative to traditional RC or steel jacketing, especially in T-shaped RC joints [ 18 , 19 , 20 , 21 , 22 , 23 , 24 ], as well as in beams and columns [ 25 , 26 , 27 , 28 , 29 , 30 ].…”

Influence of Carbon Fiber-Reinforced Ropes Applied as External Diagonal Reinforcement on the Shear Deformation of RC Joints

“…Reinforced concrete structures are usually designed and constructed with steel bars as reinforcement. Nevertheless, new materials like Fiber Reinforced Polymers (FRPs) in the form of sheets or bars have also been reported for the strengthening or rehabilitation of deficient or damaged reinforced concrete elements [1][2][3][4][5][6][7][8][9][10][11]. A review with an extensive database extracted from the literature about tested beam-column joints strengthened with FRPs are presented in a state-of-the-art report by Pohoryles et al [5].…”