Recherche de developpement d'emploi des sables issus de roches massives siliceuses et silicatees dans les betons hydrauliques

Because of the depletion in some parts of France of the alluvial sands normally used for hydraulic concretes, consideration has been given to using sands produced by crushing massive rocks as a substitute. Rocks of twelve different mineralogical types, representing most of the types of rock found in France, have been investigated. Attempts were made:

- to determine the maximum acceptable filler content of the sands, in terms of the properties of the mortars and concretes in both the fresh and hardened conditions;

- to assess the risks of alkali-aggregate reactions;

- and to work out the best techniques for the industrial production of these sands, so that the filler content and particle size distribution are compatible with the results of the research on mortars and concretes.