Evaluation of Durability of Concrete with Mineral Additions with regard to Chloride-Induced Corrosion

Report, 2016

This report presents the results from a study of modelling of chloride ingress and corrosion initiation in concrete with Portland cement and with fly ash and ground granulated blast-furnace slag as mineral additions. Durability of concrete with mineral additions and general models for chloride ingress in concrete are briefly reviewed. Chloride threshold values for corrosion initiation are discussed. The ClinConc model was employed to model the chloride ingress profiles after exposure under marine and road environments for 100 years. The model was validated using the field data after exposure in the Swedish seawater for about 20 years. The results show that the addition of mineral additions in general increases the resistance of concrete to chloride ingress. In consideration of both chloride resistance and alkalinity, the concrete with mineral additions still reveals sufficient margin to allow a significantly lower chloride threshold for initiation of corrosion of reinforcement steel in concrete. Based on the results from this study, some values of minimum cover thickness are suggested for different exposure environments depending on different types of binder used in concrete to achieve a service life of 100 years.