Volume 2, Issue 8 (September 2005)
Efforts to Determine the Relationship Between Corrosion Rate and Concrete Damage Using Acoustic Emission
Over the past 20 years, the linear polarization resistance (LPR) technique has become one of the most popular techniques for determining the corrosion rate of steel in concrete. The results are then related to the amount of damage, and this parameter becomes very important in determining the amount of remaining service life of the concrete structure. Corrosion investigations that utilize polarization resistance (Rp), which is inversely related to the corrosion rate of the steel, are carried out with the knowledge that in laboratory specimens, and especially in field situations, the steel is not corroding uniformly, the changing conditions of the concrete play a major role in the corrosion rates determined, and the area over which polarization takes place is not well defined. All of these aspects become even more important when the concrete/reinforcement system is changed because the choice of the metallic material changes or the concrete changes due to the addition of admixtures. These factors will be discussed based on an investigation in which LPR was used in combination with Acoustic Emission (AE), which can offer more direct information about the extent of damage. The goal is to be able to provide insight into the complicated relationship between the corrosion rate of the metal reinforcement, the damage to the surrounding concrete, and the remaining life of the concrete structure.