Upgrading of Reinforced Concrete Joints with Carbon Fibre Sheets

This paper presents the results of an experimental study performed in order to evaluate the ability of CFRP sheets in upgrading an exterior RC joint by preventing the plastic hinge formation at the face of the column. In this study, three 1/2.2 scaled-down RC exterior joints of a typical Ordinary Moment Resisting Frame (OMRF) were tested under monotonic load. One specimen was used as a control while the other two were strengthened with CFRP sheets of different lengths. All specimens were loaded monotonically to failure under a displacement-controlled regime. The results show that (when carefully designed), carbon fibre sheets can effectively relocate the plastic hinge away from the face of the column. Non-linear numerical analysis using ANSYS provided an insight to the expected failure mechanism and to this phenomenon. In this paper, the results of the experiments and the numerical analyses are presented and discussed.