METHOD OF CONCRETE HYDROPHOBISATION Russian patent published in 2020 - IPC C04B41/00 C04B41/46 C04B40/00 C04B24/00 C04B28/00 C04B111/27 

FIELD: construction.

SUBSTANCE: invention relates to methods for hydrophobisation of concrete or mortar. Method of producing hydrophobisated concrete comprises steps of: (A) providing a cement slurry suitable for making concrete; (B1) adding an aqueous dispersion of an alkyl ketene dimer, containing (a) an alkyl ketene dimer of formula

and/or formula

,

where R¹ and R² are identical or different hydrocarbon radicals containing 10–24 carbon atoms, or alkyl ketene dimer in solid form; (b) at least one emulsifying agent which has nitrogen content ≤ 1 wt. % selected from a group consisting of starch, cellulose, a starch derivative or a cellulose derivative; (c) a condensation product of phenolsulphonic acid and formaldehyde, naphthalenesulphonic acid and formaldehyde or naphthalenesulphonic acid, phenol, formaldehyde and urea, where sulphonic acid groups can optionally be present in protonated or deprotonated or partially in protonated and partially deprotonated form, where the dispersion has charge density in the range of -5 to -150 mcEq/g; to cement mortar and allowing cement mortar to harden or (B2) permitting cement mortar of step (A) to solidify, and applying said aqueous dispersion of alkyl ketene to the surface of hardened cement.

EFFECT: technical result is effective volume and surface hydrophobisation of concrete without significant deterioration of properties, such as workability.

17 cl, 8 tbl, 3 ex