Analytical and experimental study on seismic performance of RC T-beams with design deficiency in steel bar curtailment

In this study, a seismic assessment model using traditional RC section analysis and variable-angle truss model for prediction of angle of concrete diagonal cracks, can provide a simple evaluation of the seismic performance of beams with longitudinal rebar curtailment. A preliminary test programme was performed to verify the prediction of the assessment model and to investigate the seismic response of existing building frames and their rehabilitation. Analytical and experimental results show that reinforced concrete beams with beam bar cut-off designed according to earlier codes, such as ACI 318-71, may have deficiencies and require retrofitting. The presence of FRP plates can successfully correct the bar curtailment deficiencies and achieve rotation levels greater than those expected to be imposed during an earthquake.