Numerical Modelling of an Exterior RC Beam Column Joint Subjected to Cyclic Loading Strengthened Using UHPFRC and CFRP

A poorly detailed reinforced concrete (RC) beam-column joint (BCJ) is highly susceptible to damage under seismic forces due to the generation of shear stresses. Shear stresses are generated due to the continuous change in the direction of the compression and tension forces acting on the beam-column joint. As a result, the strength, stiffness and the energy dissipation of the whole structure is affected. It needs to be addressed beforehand by improving its shear, tensile and energy dissipation capacities so that the damage is minimised. So a structure needs to be strengthened prior to any major damage. In the present study the seismic performance assessment of a BCJ strengthened by a combination of ultra-high performance fibre reinforced concrete (UHPFRC) and carbon fibre reinforced polymer (CFRP) has been done analytically in ABAQUS. The seismic parameters observed are the hysteresis response, strength, stiffness, ductility and energy dissipation of the specimens strengthened both by UHPFRC and CFRP. From the results it is clear that the combination of the two strengthening schemes is very efficient in increasing the peak load 2.62 times and the ductility by almost 6% of the specimens as compared to the specimens strengthened using only one scheme. Also the energy dissipation shows an increase of 7.3% in case of using the combination strengthening strategy. The rate of degradation of the strength is also reduced substantially.