Introduction of durability in the project of concrete structures

Abstract

The nunber of reinforced concrete structures with durability problems, mainly rebar corrosion, has been increasing during the last few yars, as a result of the these strustures. The loss of rebar protection by the cncrete cover may occur due to various factors, but the main one is the depassivation of the rebar due to carbonation or chloride ions. In both cases, the structure as a whole is damged by the environment, in spite of the fact that corrosion only happens in some limited regions. This occurs as a result of the electrochemical process where anode areas are surronded by cathode ones. This paper presents four recently adopted concepts for predicting the deterioration evolution of reinformed concepted concrete strudtures. Models for corrosion development are described which allow and for designing the lifespan of existing structures submitted to aggressive environments.