1.1 ,This specification covers blended supplementary cementitious materials that result from the blending or intergrinding of two or three ASTM compliant supplementary cementitious materials, for use in concrete or mortar where hydraulic or pozzolanic action, or both, is desired. The supplementary cementitious materials include slag cement conforming to Specification C989/C989M, natural pozzolans and coal fly ash conforming to Specification C618 and silica fume conforming to Specification C1240.