Corrosion effects of RC bridges considering the climate change impact

Climate change is associated with significant variations of temperature, atmospheric humidity, and carbon dioxide concentration levels. These changes potentially produce a double negative effect on the safety and the life cycle of civil engineering structures: increased climatic actions and rate of material degradation. In fact, changes in these variables affect the service life of reinforced concrete and steel structures by acting on the rate of carbonation and corrosion. Corrosion has a detrimental effect especially on the seismic vulnerability influencing strength, ductility and affecting the dynamic response and consequently the failure of reinforced concrete structures. Particularly bridges, as structures directly exposed to the weather effects, are more susceptible to these phenomena. In this paper, a framework to quantitatively account for the effects of climate change on carbonation-induced corrosion is proposed, focusing on the loss of concrete passivity, and thus widespread corrosion. Different scenarios for the expected variations in CO2 concentrations and temperature are analyzed and seismic risk indexes are evaluated through a real case study of bridge located in the province of Massa-Carrara (Italy).