Service Life Forecasting for Reinforced Concrete Incorporating Potential-Dependent Chloride Threshold

Abstract

The chloride corrosion threshold of steel in concrete depends not only on concrete and steel properties but also on the potential of the steel while it is still in the passive condition. An innovative model to predict corrosion in reinforced concrete structures is presented, incorporating potential dependence and corrosion macrocell effects. The novel approach integrates the initiation and the propagation stages of corrosion in a single predictive model. The model is applied to a generic, partially submerged, reinforced concrete marine pile. The purpose of this paper was to establish and illustrate the concept of a functional approach to implement potential-dependent chloride threshold in corrosion damage projections, plus articulation of the initiation and propagation stages, in one predictive model. The long-term damage projection results are markedly lower contrasted with those of an identical system with a time-invariant chloride threshold. The results show that implementing chloride threshold dependence on potential can reveal otherwise ignored damage progression trends that may impact structural design decisions to control corrosion.