Retrofitting nonseismically detailed exterior beam–column joints using concrete covers together with CFRP jacket

Abstract

This paper introduces a new method for retrofitting reinforced concrete (RC) exterior beamcolumn T joints, using segmental circular concrete covers together with Carbon Fibre Reinforced Polymer (CFRP). Two RC T connections without transverse reinforcement at the joints were cast and tested. The first connection (Strengthened specimen, TS) was glued with the concrete covers around the column at the joint area to modify it from a square to a circular section and then it was wrapped with CFRP to strengthen its capacity. A load was first applied on the second connection (Repaired specimen, TR) to cause a serious failure then it was repaired. The repair scheme of the second connection was identical to the first connection. Results of testing the two connections have shown that the performances of both the strengthened and the repaired connections were improved significantly. The glued concrete covers worked well with the existing concrete to resist shear load. Moreover, the wrap on the modified circular sections helped in increasing the effectiveness of CFRP by increasing the confinement effect on the concrete and reduce the possibility of debonding of CFRP at the joints.

A State-Of-The-Art Review on Retrofitting Beam-Column Joint Using GFRP with NSM Technique under Seismic

“…This may be attributed to insufficient strength to withstand the lateral loads by the connection due to the reason of being poor detailing without consideration to seismic provisions. This problem leads to decrease in ductility with diagonal shear developed in the connection leading to catastrophic failures [16]. Accordingly, when large lateral forces are applied during earthquakes, such joints may severely get damaged.…”

Behaviour of perforated GFRP tubes under axial compression

“…The use of FRP composites to strengthen reinforced concrete structures has been widely studied in the last two decades [19][20][21][22][23]. Recently, Wang et al [24] and Hadi et al [25] proposed a new reinforcing scheme named FRP tube reinforced concrete columns in which perforated Glass Fibre Reinforced Polymer (GFRP) tubes…”

Experimental Assessment of RC Beam‐Column Connections with Internal and External Strengthening Techniques

“…e reinforced concrete beam-column connections were typically nonengineered. e studies [25][26][27][28][29][30][31][32][33] about retrofitting of RC joints with FRP express the occurrence of strength increase in joint sections with brittle failure. In addition to all the studies about retrofitting reinforced concrete members, there are few studies about fatigue behavior of the strengthened members, expressing long-term behavior [34].…”