Modeling Time to Corrosion Initiation in High-Performance Ferrocement Exposed to Chlorides Environments


The applications of a mineral admixture, or a zinc coating to steel surface, or acombination of both are methods used for the corrosion prevention of ferrocementelement in this study. Results of a study to evaluate many corrosion protection systemswith metakaolin and/or galvanized steel mesh are presented in six U-shaped specimens.Specimens were built to simulate exposure conditions typical for marine environment.Laboratory data collected along duration of 40 weeks of exposure were used inmodeling the cover depth as a function of time to corrosion initiation of the investigatedcorrosion prevention methods. Methods used to assess the condition of specimensincluded chloride concentration measurements, and corrosion rates. Model predictionsshow that the ferrocement specimen of high-performance mortar with metakaolinprovides much better level of protection against moisture and chlorides than theconventional specimen, by delay rate of chloride ingress. Application of a galvanizedsteel mesh causes an elevation of the chloride threshold resulting in an additionalincrease in the predicted time to corrosion initiation.