CONCRETE MIX PREPARATION METHOD Russian patent published in 2004 - IPC

FIELD: manufacture of building materials. SUBSTANCE: preparation of concrete mix comprises preliminary stirring of part of tempering water, sand, and additive followed by adding the rest of tempering water. Preparation of concrete mix further comprises addition of coarse filler, in particular crushed stone. As additive, solution of sulfate-type naturally occurring bischofite MgCl₂•6H₂O with density 1.24-1.35 t/cu.m and molecular weight 203.303 is used in amount 2 to 12% on the weight of cement. Preliminary stirring is carried out with 30-70% tempering water and 1/2 to 1/4 parts of sand during 2-5 min and the rest of sand is added during further stirring. EFFECT: lowered cost price of concrete and increased its strength at winter concreting. 8 tbl