Slip Effect on Rotational Capacity (Chord Rotation) of Corroded RC Members Due to Pull Out of Steel Reinforcement

Based on ongoing experimental research, the present manuscript presents the effect of the slippage of a steel reinforcing bar due to corrosion on the chord rotation and deformation of corroded Reinforced Concrete members. The experimental results recorded that the increase in the corrosion level of the steel led to bond strength loss and relative slip between the steel and concrete, which was increased from 1.5 mm in non-corroded conditions to 3.5 mm even at low corrosion levels, up to a 5% steel mass loss. This slippage of corroded reinforcing bars from the anchorage leads to a proportional increase in terms of chord rotation due to pull out resulting in an additional increase in the displacement of the column’s top. In conclusion, the present study highlights the great importance of the contribution of the resulting slippage of a steel reinforcing bar due to corrosion in the calculation of the limit chord rotation (column–beam), a term which is of major importance in the assessment of the structural integrity of old RC structures, which was introduced as an adequacy requirement by both Eurocode 8-3 and the Greek Code of Structural Interventions (KAN.EPE).