METHODS FOR PRODUCING AIR-CURED FIBER CEMENT PRODUCTS Russian patent published in 2021 - IPC C04B28/04 C04B40/02 B28B1/52 B28B3/00 C04B111/20 

FIELD: cement products.

SUBSTANCE: group of inventions relates to a method for producing air-cured fiber cement products, a cured product and its application. The method for producing air-cured fiber cement products includes stages of: (a) providing cured fiber cement powder by crushing cured fiber cement plates to the particle size from 0.1 to 400 mcm; (b) providing an aqueous fiber cement solution containing water, a binder – Portland cement, cellulose and polyvinyl alcohol fibers, compacted fine-dispersed silicon dioxide and/or a filler – calcium carbonate, and the specified cured fiber cement powder in amount from 5 to 40 wt.% per dry mass of the specified solution; (c) providing a raw fiber cement sheet; (d) pressing the specified sheet under pressure from 180 to 250 kg/cm² for 5 to 15 min; (e) preliminary curing the specified raw fiber cement sheet at 60°C for 1-10 h; (f) air curing the specified raw fiber cement sheet, while providing the air-cured fiber cement product. The group of inventions is developed in independent and dependent claims of the formula.

EFFECT: increased strength, reduced density and water absorption, waste disposal.

11 cl, 22 dwg, 5 tbl, 6 ex