The Corrosion of Steel In a Reinforced Concrete Bridge

Abstract Studies were made to determine the cause of accelerated corrosion of reinforcing steel in a concrete bridge in a salt water environment. There was good reason to believe that macro-galvanic corrosion was involved. Resistivity and corrosion cell ratio charts indicate that the resistivity of concrete decreases as the deterioration of the concrete increases. The lower resistivity measurements of the concrete in the anodic areas indicated that the anodic areas could have been created by the following factors: (1) a greater moisture content in the anodic areas, and (2) a greater sea salt content in the anodic areas. Cathodic protection may offer a means of curbing corrosion but certain precautions should be taken. All available data indicate that in new installations in salt water environments, corrosion problems can be minimized by using a concrete formulation having minimum porosity and by a design having a maximum coverage of concrete over the reinforcing steel. 6.6.5.