Web-bonded FRPs for relocation of plastic hinges away from the column face in exterior RC joints

Abstract

In an RC building subjected to lateral loads, the beam-column joints constitute one of the critical regions. In existing frames, which were not adequately designed, a practical way of controlling plastic hinging and implement the strong-column weak-beam concept is through the use of a web-bonded FRP retrofitting system. This paper presents the results of an experimental and numerical study carried out in order to evaluate the ability of CFRP sheets in preventing the plastic hinge formation at the face of the column in exterior RC joints. Seven scaled-down RC exterior joints of a typical Ordinary Moment Resisting Frame are tested under moderately monotonic/cyclic loads. Two specimens are used as control while the other five are CFRP-strengthened/repaired of different lengths and thicknesses. The results show that carbon fibre sheets can effectively relocate the plastic hinge away from the face of the column. Non-linear numerical results using ANSYS are also presented and discussed.