ADDITIVE FOR CONCRETE MIXTURE Russian patent published in 2009 - IPC C04B28/06 C04B111/20 

FIELD: building.

SUBSTANCE: invention refers to building materials and can be implemented in industrial and civic engineering at preparation of concrete and reinforced concrete items and also at construction of buildings of special purpose. The additive for concrete mixture contains, wt %: micro-silica with specific surface S_sp=2000 m²/kg - 60.60-62.40; super-plasticiser C-3 - 4.25-4.55, sodium nitrite - 2.75-3.03; sol of iron hydroxide (III) - 1.46-1.52; open-hearth furnace dust with contents of Fe (III) not less 60 wt % and Zn (II) not more 1.0 wt % - 29.14-30.30.

EFFECT: upgraded durability at compression, reduced shrinkage and abrasiveness.

1 ex, 1 tbl