3. Sustainability indicators and other parameters

3.1 Defining sustainability indicators

The new approach to durability requires durability indicators. These are parameters relating to the constituent material concrete (sound), which appear to be fundamental for assessing and predicting the durability of the material and structure with regard to one or more degradation processes. For example, they are included in the equations governing the phenomena, and form part of the input data for service life prediction models. This first condition ensures their theoretical relevance. A second condition must also be met: these parameters must be easily quantifiable from laboratory tests carried out on specimens or samples, according to well-defined and validated operating procedures. Test methods must also be reproducible, accurate, simple...