Modeling the deterioration of the coating on steel structures: a comparison of methods

Steel structures like bridges, tanks and pylons are exposed to outdoor weathering conditions. In order to prevent them from corrosion they are protected by organic coating systems. This paper focuses on the deterioration process of the organic coating layer that protects steel structures from corrosion. Only if there is sufficient knowledge of the condition of the coating on these structures, maintenance actions can be done in the most efficient way. Therefore the deterioration of the coating in course of time has to be estimated accurately. To this end the Brownian motion with non-linear drift, the Gamma process with non-linear shape function and the simulation of a physical process are compared. Expert judgment is used to obtain parameter estimates.