Corrosion protection, long-term performance requirements

Long term performance of a good coating for corrosion protection requires ... 

Requirements specified in this way are deemed-to-satisfy rules. Such rules cannot be used to quantify the performance of the structure in general, specific effects of additional measures (for instance increasing the cover to the steel), or the consequences of sub-standard practice (for example using a higher w/c). In this respect it is important to note that EN 206 also allows the use of alternative performance-related design methods with respect to durability that consider in a quantitative way each relevant deterioration mechanism, the service life of the element or structure, and the criteria that define the end of the service life. Such methods should draw a picture of the characteristics that the concrete must possess to protect the reinforcement for the service life requested from a predictive model of the corrosion attack. These refined methods (as opposed to standard methods) may be based on long-term experience with local practices in local environments, on data from an established performance test method for the relevant mechanism, or on the use of proven predictive models. 

In general, reinforced concrete has proved to be successful in terms of both structural performance and durabiHty if the design mles (Chapter 11) and concrete technology (Chapter 12) were adequately considered. Additional protection measures will only be necessary in very aggressive environments or when a very long service life is required. As outlined in Section 11.8, corrosion inhibitors, thus chemical compounds added as admixtures to the fresh concrete, are one possible way to improve the durabiHty of concrete structures. 

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