Performance based deemed-to-satisfy rules

A new concept is presented for the future design of reinforced concrete structures with regard to environmental effects which limit durability. The concept is similar to the well-established procedure for the specification of concrete strength. The new design concept is applied for the carbonation of concrete where material performance is classified into resistance classes. A wide range of concrete compositions were tested, analysed and allocated to a particular resistance class. For a given material resistance class, the required minimum cover to withstand a particular environmental load (XC4 exposure class) in dependence of a freely selectable target design service life can be found from a design chart. International deemed-to-satisfy rules for concrete cover are proposed.