FIELD: chemistry.
SUBSTANCE: invention relates to construction materials, specifically to an additive for gypsum binder, dry construction mixtures, mortar and concrete based thereon, used in construction of residential and public buildings. The additive for modifying gypsum binder, dry construction mixtures, mortar and concrete contains powdered calcium hydroxide, potassium hydroxide, plasticiser - sodium polycarboxylate, antifoaming agent AXILAT, water-repellent agent - sodium polymethylsiliconate and a setting retarder - sodium gluconate in the following ratio, wt %: calcium hydroxide 52.0-70.8, potassium hydroxide 1.0-4.6, sodium polycarboxylate 13.5-18.3, AXILAT 4.1-7.0, sodium polymethylsiliconate 6.6-12.0, sodium gluconate 4.0-6.1. Said additive has specific surface area of 710-720 m2/kg.
EFFECT: improved physical and mechanical properties of gypsum binder, dry construction mixtures, mortar and concrete owing to use of the disclosed additives, as well as reduction of power consumption for preparing the additive with specific surface area of 710-720 m2/kg.
2 cl, 16 ex, 1 tbl
