Time Dependence of Chloride Induced Macro Cell Corrosion with Large Cathodes

As part of the scientific research group FOR 537 „Modelling of Reinforcement Corrosion” the aim of this project is to examine the time dependence of chloride induced macro cell corrosion of steel in concrete under relevant boundary conditions. Based on a well established model describing the corrosion process by means of an electrical circuit the time dependent behaviour of the driving voltage deltaE(t), the anodic characteristics as there are the anodic polarization resistance r_a(t), the actually corroding surface A_a(t) the distribution of corrosion damages deltaA_s(t) on the steel surface as well as the electrochemical characteristics of the cathodes will be investigated.

In an extensive 2 year laboratory campaign corrosion monitoring of a total number of 120 macro cell test specimens will be conducted. In specified time intervals the anodic parts of these specimens will be dismounted and subsequently investigated by means of an optical high resolution 3 D surface scanner in order to characterise the actually corroding surface areas as well as the distribution of corrosion damages. Finally the time dependence of the investigated parameters shall be considered in numerical calculation models for chloride induced macro-cell corrosion of steel in concrete.