Strengthening of Exterior RC Moment-Resisting Beam-Column Connections Using Fibre-Reinforced Polymers and Ferrocement

This paper presents an experimental investigation wherein two different composites are compared based on their strengthening effectiveness. The composites selected here for comparison are ferrocement and two variants of fibre-reinforced polymer (FRP), namely carbon FRP (CFRP) and glass FRP (GFRP). The performances of these three composites were compared in strengthening reinforced concrete exterior beam-column joints under reversed cyclic loading. Initially, the selected composites were made equivalent in terms of their tensile strength to make the comparative study on a level playing field. Seven beam-column joint specimens were subjected to different levels of distress and were strengthened using equivalent laminates of these composites. The rehabilitated joints were tested up to failure and compared their behaviour in terms of load-deflection relationships, failure modes, displacement ductility, energy dissipation capacity, and stiffness degradation. The experimental results indicate that ferrocement performs superior to GFRP and moderately similar to CFRP in improving the load-carrying capacity. The results obtained were in good agreement with the theoretical predictions based on ACI codes. A cost analysis done on these strengthening schemes shows that ferrocement can effectively be an economical alternative to FRPs in strengthening beam-column joints.