ABSTRACT
Degradation due to corrosion of reinforcing bars is one of the principal deterioration phenomena affecting reinforced concrete structures (Bertolini et al. 2004). It is widespread all over the world; every year a great amount of funds is assigned to maintenance and repairing works for deteriorated structure and infrastructure. Therefore the analysis of structural behavior of corroded structures, such as bridges, is becoming an urgent need for both risk evaluation and priority assignment of intervention. Corrosion of steel in concrete deeply modifies the structural behavior of reinforced concrete structures (Tondolo 2006). In fact, the oxide formation on the surface of the rebar in contact with concrete generates a significant volumetric expansion of this new layer of granular material. The radial pressure determines tensile stress orthogonal to the rebar axis and generates radial cracks on the surrounding concrete. Due to corrosion, a reduced performance of concrete elements is observed especially in service conditions. Bond mechanism is activated by cracking of concrete; its reduction generally is followed by an increase of crack opening. As serviceability and durability of concrete structures can be seriously affected by the aforementioned effects (Bhargavaa et al. 2006), control and monitoring of corrosion assume a significant importance in safety reassessment, as well as in the evaluation of the overall economic utility of an intervention (Ceravolo et al. 2009). Changes in the structure’s dynamic properties may often provide quantitative evidence that damaging phenomena are underway.
