METHOD OF PRODUCING READY-MIXED CONCRETE AND HYDRAULICALLY HARDENING COMPOSITIONS USING AN ADDITIVE BASED ON RECYCLED CONCRETE WASTES Russian patent published in 2024 - IPC B28C5/00 C04B28/02 

FIELD: construction.

SUBSTANCE: invention relates to construction industry, in particular, can be used in production of ready-mixed concrete, hydraulically hardening construction compositions based on portland cement by replacing part of the cement with a dust-like fraction (less than 150 mcm), which is formed during processing of concrete scrap, in the form of a colloidal suspension obtained by its mechanochemical activation in a solution of an alkaline agent. Method of producing ready-mixed concrete and hydraulically hardening cement compositions using an additive based on recycled concrete wastes, including obtaining an additive based on recycled concrete wastes by mechanochemical activation of a dispersed powder of a dust-like fraction of a cement-sand stone (DFCSS), said additive based on recycled concrete wastes is added to the mix to produce concrete, mix components are mixed in a mixer to obtain a consistency suitable for moulding articles. Activated dispersed powder of the dust-like fraction of the cement-sand stone with particle size of 150 mcm and less is mixed with an aqueous solution of NAOH, having concentration of 0.01 M to 0.03 M, in ratio of 1:1.2, mechanochemical activation of the dispersed powder of said dust-like fraction of the cement-sand stone in an aqueous solution of NAOH is carried out for 3–5 seconds at room temperature to obtain a colloidal additive, which is a DFCSS powder with a hydroxylated surface of particles, the obtained colloidal additive is added to the mixture for producing concrete and hydraulically hardening compositions for replacing 20–30 % of portland cement.

EFFECT: improved structure, preservation and improvement of strength properties of ready-mixed concrete and hydraulically hardening compositions.

1 cl, 13 ex, 1 tbl, 3 dwg