2. Evolving concepts and technologies

2.1 Durability of structures

When the first radiation protection concretes were developed, right from the start of nuclear activities, engineers successively focused their efforts on :

• identification of substances that are effective in stopping radiation (cost-effectiveness optimization);

• formulation of new concretes incorporating the selected substances (feasibility);

• characterization of these new materials in terms of intrinsic performance (mainly thermomechanical properties).

At the time (1945-1965), the notion of durability was all the less present in this approach as it had not yet appeared in the field of civil engineering, and...