Corrosion of reinforcing steel produces important damage to concrete structures in coastal, urban, and industrial zones. This damage has increased in recent years in all countries when concrete is a regular construction material, no matter if it is a technologically advanced country or it is in the process of being one. Reinforcing steel is initially protected by concrete alkaline reserve which helps to maintain the reinforcing steel passive layer. However, chlorides from salty water (i.e., marine water and/or deicing salts) or CO2/SO2 present in urban/industrial environment accumulate on the concrete surface and then move towards the rebar by known transport mechanisms like diffusion. When the chloride or CO2 threshold is exceeded, depassivation occurs and a corrosion products layer is formed in the rebar perimeter. The volume of this layer is bigger than the original steel consumed; thus, tensile stresses develop and produce concrete cover cracking and spalling. Besides being aesthetics, cracking decreases steel/concrete adherence and, potentially, the structural capacity of the affected structural element. Then, corrosion of reinforcing steel can produce significant damage affecting the whole structural behavior.

Peer Reviewed