METHOD OF PRODUCTION OF BINARY PLASTICIZED PORTLAND CEMENT BINDERS Russian patent published in 2007 - IPC C04B7/04 

FIELD: manufacture of building materials; production of cement compositions on base of binary plasticized portland cement binders for manufacture of monolithic prefabricated reinforced concrete items.

SUBSTANCE: proposed method includes joint grinding of portland cement clinker with modified gypsum stone; for obtaining the gypsum stone, hemihydrated gypsum is first mixed with superplasticizing agent solution; after hardening and drying, joint grinding is continued till specific surface of 280-550 m²/kg has been obtained; superplasticizing agent is introduced together with mixing water. According to another version, method of production of binary plasticized binder includes joint grinding of portland cement clinker with modified gypsum-mineral stone which is obtained through mixing the hemihydrated gypsum with active mineral additive at the ratio of from 1:1 to 1:15; then, product is mixed with superplasticizing agent solution and after hardening and drying joint grinding is continued till specific surface of 280-550 m²/kg has been obtained; superplasticizing agent is introduced together with mixing water. Used as superplasticizing agent are modified lignosulfonates, sulfonated melamine-urea resins or naphthalene formaldehyde resins.

EFFECT: low water demand of binders; reduced shrinkage; enhanced resistance to cracking at initial hardening stages of concrete and reinforced concrete items.

4 cl, 2 tbl, 2 ex