Infrastructures and industrial buildings are commonly exposed to aggressive environments and damaged by corrosion. In prestressed reinforced concrete structures, the potential risks of corrosion could be severe since reinforcements are already subjected to high amounts of stress and, consequently, their load-bearing capacity could abruptly decrease. In recent years, some experimental studies have been conducted to explore the flexural behavior of corroded pretensioned reinforced concrete (PRC) beams, investigating several aspects of residual structural performance. Although many studies have been done in this area, there is no concise paper reviewing the state-of-the-art research. Accordingly, the main objective of this paper is to provide a review of the available experimental tests for residual capacity assessment of corroded PRC beams. Based on the state-of-the-art review, a degradation law for the flexural strength of corroded PRC beams is suggested.

The corrosion of steel bars in concrete is a dangerous and extremely costly problem that causes losses of serviceability and structural capacity in buildings and bridges. Once the depassivation occurs, because of concrete carbonation or chloride attack, the oxides occupy approximately 2–6 times the iron volume, causing a pressure at the steel–concrete interface, and consequently cracks and bond-slip degradation. In particular, the reinforcement-concrete bond degradation influences the deformability of the element and consequently its service behavior. The present study is a part of an extensive research project—CONSTIN, between Oslo Metropolitan University and Niccolò Cusano University—aiming to evaluate the steel-to-concrete interaction in the presence of corrosion and to establish a variation law for the bond strength as a function of the corrosion level. The research assess the influence of different levels of corrosion on the interaction between the concrete and the most typical steel reinforcement typologies (steel strands and smooth and ribbed bars), characterized by the same diameter (equivalent to 12 mm) and bonded length. The different level of corrosion is reached with a specific duration of exposition of the embedded reinforcements to the accelerated electrolytic corrosion process. Some details about the laboratory procedure, the duration of exposition and the current density are provided. The preliminary results of the experimental campaign are presented.

Prestressed reinforced concrete beams are widely used in industrial and commercial buildings, which are commonly exposed to aggressive environments and damaged by corrosion. This precast construction technique has also been used for the last 50 years in most viaducts and bridges built in many countries like Italy. According to previous literature results, the corrosion of prestressed concrete structures causes the size reduction of strands, degradation of mechanical properties of steel, cracking of the surrounding concrete and bond decay at the steel-to-concrete interface. The mixing of these effects strongly reduces the bearing-capacity of prestressed reinforced concrete members, changing the failure mechanism as well. In the framework of the OPTION research project between Niccolò Cusano University and Oslo Metropolitan University, an experimental campaign investigates the behavior of corroded prestressed beams. Four prestressed beams (cross section size 200 × 300; total length 3000 mm; clear span 2700 mm) were first subjected to artificial corrosion, to obtain different damage levels, and were then tested in four-point bending. The goal is to estimate the corrosion level that makes a deteriorated prestressed reinforced concrete beam less ductile while keeping the strength unchanged. In the present study, the first experimental results and some details about the laboratory procedure are presented.