This test method is intended to give a relatively rapid indication of the potential expansive reactivity of certain carbonate rocks that may be used as concrete aggregates. The test method has been successfully used in (1) research and (2) preliminary screening of aggregate sources to indicate the presence of material with a potential for deleterious expansion when used in concrete.

The test method is intended as a research and screening method rather than as the basis of a specification requirement. It is intended to supplement data from field service records, petrographic examinations according to Guide C295, and tests of aggregate in concrete according to Test Method C1105.

Alkalies participating in the expansive reactions with aggregate constituents in concrete usually are derived from the hydraulic cement; under certain circumstances they may be derived from other constituents of concrete or from external sources. Two types of alkali reactivity of aggregates are recognized: (1) alkali-silica reaction involving certain siliceous rocks, minerals, and artificial glasses, and (2) alkali carbonate reaction involving dolomite in certain calcitic dolomites, dolomitic limestones, and dolostones. This test method is not suitable as a means to detect alkali-silica reaction.