CEMENT Russian patent published in 1999 - IPC

FIELD: civil and industrial engineering, grouting of oil and gas wells, making of road and aerodrome, coatings and protection of subsurface and underwater portions of structures against corroding effect of ground and sea water. SUBSTANCE: cement comprises mixture of portland cement clinkers containing set mineralogical composition and gypsum, two clinkers being used at ratios ranging from 1:1 to 1:1.5. First clinker comprises 40-55 wt % three calcium silicate and 3-8 wt % three calcium aluminate, and second clinker comprises 56-70 wt % three calcium silicate and 0.5-3 wt % three calcium aluminate, ratios of components being as follows (wt %): said mixture of portland cement clinkers, 93-97, and gypsum, 3-7. Cement comprises active mineral additive in amount of not greater than 50% based on weight of cement. EFFECT: 50% multipurpose cement having higher hardening rate, low shrinkage and water separation and improved sulfate resistance. 2 cl, 3 tbl