METHOD OF PREPARING CHEMICAL ADDITIVE FOR CEMENTS USED IN CAST-IN- PLACE CONCRETES

FIELD: manufacture of building materials. ^ SUBSTANCE: invention relates to chemical additives for controlling properties of cement-sand mixes, concrete mixes, and concretes for use in producing cast-in-place concretes. Additive is based on sodium alkylarylsulfonate obtained by sulfonation of non-rectified heavy pyrolysis resin with spent sulfuric acid followed by neutralization of sulfonation reaction mixture with sodium hydroxide. Aqueous solution of sodium alkylarylsulfonate is further used to impregnate carbonate slime, which is fine mineral powder precipitated in processes of reagent treatment of industrial waste waters and water treatment at chemical and power generation enterprises, proportion of sodium alkylarylsulfonate is 10% of the weight of indicated slime. Impregnated slime is held at ambient temperature during 2 h and dried at 90°C. ^ EFFECT: essentially improved rheological characteristics in all stages of hardening of cement, cement-sand mixes and also improved physicochemical properties of cement-sand samples. ^ 3 tbl, 2 ex