Indirect testing – the measurement of "proxy" characteristics that can be correlated to actual performance and hence durability (e.g. porosity for freeze-thaw resistance and hardness for abrasion resistance).
A further option, which may be easier to implement, would be for technical specifications to define "proxy" characteristics of the product or material itself, which could be determined without requiring the testing of the finished element. This possibility is already mentioned in some mandates, such as the use of density as a proxy for airborne sound insulation in masonry, but could also be considered in other circumstances.
