On the Influence of Corrosion Levels in the Dynamic Behavior of Pretensioned Concrete Structural Elements

Corrosion of internal reinforcements represents a serious issue in prestressed concrete structures, as it progressively decreases the load bearing capacity of components, hence contributing to reduce the service life of the whole structure and potentially inducing unexpected and uncontrolled cracking phenomena. A proper assessment of the health status of a structural element is the key priority of any Structural Health Monitoring (SHM) system. As SHM systems are finally getting the credits they deserve, given their relevance in keeping structures monitored and hence in contributing to people life safety, the focus has shifted towards the development of automated approaches to promptly detect incipient damages potentially jeopardizing the structural integrity of the target system. Within this context, this chapter, which describes a part of a wider research program targeted to the development of robust strategies for SHM of civil structures, aims at discussing a preliminary study carried out to identify the potential correlation between corrosion levels in pretensioned concrete elements and their dynamic behavior. Several pretensioned concrete beams of the same geometry (cross section 200 × 300 mm; total length 3700 mm) have been subjected to an artificial corrosion process that was induced through electrolytic cells by dipping the beams within a 3% saline solution, up to half of the height of the cross section. Four-point bending tests were performed up to failure. Dynamic impact tests were also performed to identify any eventual variation in terms of dynamic behavior of the beams. The chapter shows that increased corrosion induces wider changes in the dynamic behavior of the structural elements.