Non-linear flexural behaviour of RC columns including bar buckling and fatigue degradation

An advanced fibre-based modelling technique is developed to characterise the non-linear flexural behaviour of rectangular reinforced-concrete (RC) columns by accounting for the influence of inelastic buckling and low-cycle fatigue degradation of vertical reinforcement. The proposed uniaxial material model of reinforcing steel is calibrated using 22 rectangular RC column tests. The influence of inelastic buckling of vertical reinforcement on the non-linear cyclic response of rectangular RC columns is investigated. The calibrated model is capable of accurately predicting the non-linear response of rectangular RC columns up to complete collapse by taking into account the additional failure modes of the RC columns.