METHOD TO PRODUCE COMPLEX ADDITIVE FOR AIR PLACED CONCRETE (VERSIONS) Russian patent published in 2015 - IPC C04B22/08 C04B111/20 

FIELD: construction.

SUBSTANCE: method to produce a complex additive for air placed concrete according to the version 1 includes pre-heating of water to 60-110°C, subsequent dissolution of aluminium sulphate, diethanol amine, fluorhydric acid and compounds with common formula Na_xH₃-_xPO₄, where x=0÷1.5. Then mixing is carried out to complete dissolution, afterwards sodium aluminate is introduced to produce the following composition (wt %): aluminium sulphate 25-35; diethanol amine 3-10; sodium aluminate 3-8; fluorhydric acid 2-10; derivatives of phosphoric acid 1-5; balance - water. The method to produce a complex additive for air placed concrete according to the version 2 includes pre-heating of water to 60-110°C, serial dissolution of aluminium sulphate, diethanol amine and sodium aluminate, mixing until complete dissolution, afterwards they introduce a mixture of magnesium oxide and formic acid to produce the following composition (wt %): aluminium sulphate 35-50; diethanol amine 0.2-0.5; sodium aluminate 3-6; magnesium oxide 1-3; formic acid 2.5-7.5; balance - water.

EFFECT: increased stability of additive storage under negative and sign-alternating temperatures without deterioration of its efficiency when used in technology of air placed concrete.

2 cl, 2 tbl