FIELD: building materials industry, petroleum and mining industries. SUBSTANCE: portland cement comprises mixture of ground clinkers of different mineralogical composition, and gypsum, mixture including at least three ground clinkers having different mineralogical composition and grinding fineness. Instead of part of mixture of clinkers, cement may contain active or inert additives in amount of up to 60% based on weight of cement. EFFECT: improved early strength of portland cement. 2 cl, 3 ex
