The Quest for Absolute Concrete Durability Performance Criteria

Deemed-to-satisfy durability requirements, as typically provided in code prescriptions (minimum cement content, maximum water cement ratio, minimum strength class) are now approaching their limits of applicability. With the implementation of new tailor-made binder types, including a multitude of powders (reactive and even non-reactive), the prescriptive parameters cement content and water/cement ratio become unclear and do not always correlate well with the real durability performance. While the equivalent concrete performance concept (ECPC) already offers a first way out of this debate, it still fundamentally maintains durability requirements at a deemed-to-satisfy level, as the new binder type needs to be experimentally calibrated relative to a standard solution. A more fundamental solution needs to consider the absolute durability performance of the concrete applied in the real structure. This performance needs to be evaluated in laboratory conditions (potential performance) as well as on the final structure (as-built performance). However, although straightforward in principle, the quest for absolute durability performance criteria is complicated, with remaining fundamental obstacles. This paper intends to give a general overview.