3　Terms

The following terms and definitions are applicable to this standard.

3.0.1　Cementitious material

A general designation for mineral additives which are used as concrete raw materials having cementing properties，such as cement and fly ash，silica fume，granulated blast-furnace slag，phosphorus slag powder，pozzolan，etc.

3.0.2　Water-cementitious material ratio

The ratio of the mass of water to the mass of cementitious materials used in concrete mixture.

3.0.3　Alkali-aggregate reaction

Chemical reaction between alkalis in hardened concrete and active minerals of some aggregates，resulting in concrete deleterious expansion，cracking and even damage.

3.0.4　Total alkali content of concrete

A product of mass of raw materials，such as cement，admixtures and additives per unit volume of concrete，and the effective alkali content，in kg/m3.

3.0.5　Effective alkali content

Alkali content in concrete raw materials which participates in alkali-aggregate reaction，expressed as an equivalent Na2O，that is，the sum of Na2O content and 0.658 K2O content，in %.

3.0.6　Alkali-silica reactive aggregate

Aggregate with noncrystalline silica or not completely crystallized silica；alkali-aggregate reaction may occur under certain conditions.

3.0.7　Alkali-carbonate reactive aggregate

Microcrystalline dolomite with a specific structure；alkali-aggregate reaction may occur under certain conditions.