POWDERED POLYMER-MODIFIED ADDITIVE FOR CONCRETE AND PROCESS OF CONCRETE PREPARATION Russian patent published in 2024 - IPC C04B28/04 C04B24/26 C04B40/00 

FIELD: chemistry; construction.

SUBSTANCE: group of inventions relates to a powdered polymer-modified concrete additive, which is especially suitable for road construction layers, and to a method of producing said concrete. Powdered polymer-modified additive for concrete contains: (a) from 55 to 99.4 wt.% of a polyacrylate with a core shell, having a glass transition temperature Tgk of the core ≤ −10°C, and glass transition temperature Tgs of the shell >0°C; (b) from 0.5 to 5% by weight of fumulated or colloidal silica; (c) from 0 to 8% by weight of modified polycarboxylate ether; and (d) from 0 to 35 wt.% of chalk having a value of d50 ≤ 8 mcm. Use of said additive as an additive for lean concrete with cement content of less than 12% by weight on the basis of concrete. Method of producing lean concrete, comprising a step of mixing cement with said additive and aggregate.

EFFECT: high low-temperature flexibility and water resistance, longer settling time (>12 hours) when mixing with water before using this mixture for mixing cement/concrete, high fatigue strength of layers bonded with hydraulic binding substances.

11 cl