Relocation of Plastic Hinge in RC Beams Using CFRP Sheets

Ramin Azarm¹ Farzad Raeiszadeh²

1) Iran, Islamic Azad University,Marvdasht Branch ,
2) Iran, Islamic Azad University, Beyza Branch ,

Publication : The 4th International Congress On Civil Engineering, Architecture & Urban Development(4icsau.ir)
Abstract :
Beam–column joints are critical regions of reinforced concrete (RC) structures designed for inelastic response to seismic forces. The use of carbon fiber reinforced plastic (CFRP) to improve the performance of beam–column connections is a challenging task in the retrofitting of deficient RC frames because existing slabs cause many limitations in the design and wrapping of CFRP in joints. This study proposes a flange-bonded CFRP retrofitting scheme for RC frames to relocate plastic hinges from the joint area to the beam as well as improve the capacity of beam–column joints and the stability of buildings subjected to dynamic loads. The performance of the proposed retrofitting method is numerically investigated. A full-scales RC interior joint of a moderate ductility moment resisting frame is investigated before and after retrofitting. In addition, a parametric study was conducted for the optimal thickness of FRP sheets for the relocation of the plastic hinge away from the joint. The results prove that the proposed retrofitting method can successfully shift the plastic hinge further into the beam, leading to the improved capacity and performance of the RC frames.
Keywords : Seismic retrofitting RC joint FRP pushover analysis plastic hinge