Structural behavior of severely corroded RC beams retrofitted with UHPC layer: an experimental study

Corrosion of reinforcement bars in reinforced concrete (RC) structures is considered a major concern. This study examines the flexural response of severely corroded RC beams retrofitted with ultra-high-performance concrete (UHPC) layer. UHPC layers were attached to the concrete substrate in four different configurations to investigate whether they could strengthen severely corroded RC beams. To represent carbonation-induced uniform corrosion, artificial corrosion was adopted in this study by replacing the deformed bars with plain bars and reducing the cross-sectional area. The plain steel bars represented about 38% of rebar corrosion. Obtained results revealed that UHPC layers can remarkably enhance the structural performance when it comes to serviceability and ultimate limit state. The test results also revealed that RC beams retrofitted with the UHPC layer might be unable to improve the displacement capacity of the corroded RC beam owing to bond deterioration between the concrete and embedded rebars and reduced cross-sectional area.