The definitive prescriptive nature of the exposure classes for concrete susceptible to reinforcement corrosion in the European Standard EN 206 does not adequately describe the enhanced risks of possible changing ambient environments in the lifetime of the steel reinforcement, nor does it quantify the risk of reinforcement corrosion for more constant environments. One reason for this may be the variable environmental conditions across Europe and the differing practices in the member states. A more robust environmental classification is needed based on a better understanding of the variation of moisture with depth under changing external conditions and of the resulting rate of corrosion of the steel reinforcement.
This Digest reviews recent models and data and presents supplementary information to EN 206 for the UK, based on industry practices and environmental data. 8 pages.