FIELD: chemistry.
SUBSTANCE: claimed invention relates to an additive for a hydraulic binding substance, to a composition of cement, concrete and mortar, a method of obtaining concrete and mortar and to the application of the additive of polycarboxylic acid or its salts. The composition contains in wt % relative to the total composition weight of at least from 0.01 to 3% of polycarboxylic acid or its salts, with the said polycarboxylic acid including from 2 to 4 carboxyl groups per a molecule; and from 97 to 99.99% of a Belite and Calcium Sulphoaluminate-Ferrite clinker (BCSAF-clinker), including, expressed in wt % relative to the total weight of the BCSAF-clinker, at least from 5 to 30% of a calcium alumoferrite phase with the composition, corresponding to the general formula C2AxF(1-X), in which X varies from 0.2 to 0.8; from 10 to 35% of calcium sulphoaluminate "ye'elimite" (C4A3S), from 40 to 75% of belite (C2S), from 0.01 to 10% of one or more secondary phases, selected from calcium sulphates, sulphates of alkali metals, perovskite, gehlenite, free lime and periclase, and/or a glass-like phase, and for which the total quantity of the said phases in percent is higher or equals 97%. The invention is developed in dependent items of the invention formula.
EFFECT: increased mechanical strength at the 28-day age.
16 cl, 6 tbl
