CEMENT-BASED CONCRETE MIXTURE FOR CONSTRUCTION 3D PRINTING Russian patent published in 2022 - IPC C04B28/04 

FIELD: building materials.

SUBSTANCE: invention relates to the building materials industry and can be used for the manufacture of building products and structures in the additive manufacturing technology by layer-by-layer extrusion (3D printing) of a concrete mixture based on Portland cement, sand, finely ground pozzolanic component, superplasticizer and sodium methyl siliconate. Cement-based concrete mix for building 3D printing includes Portland cement, sand, superplasticizer and water. Portland cement contains tricalcium silicate 68.1%, tricalcium aluminate 7.2%, MasterRheobuild 183 based on naphthalenesulfonates is used as a superplasticizer, quartz sand with a fineness modulus of 2.2-2.4, moisture content of 1-2% is used as sand, and additionally, the concrete mixture contains a finely ground pozzolanic component - a binary mixture of diatomite with a grinding degree of at least 1400 m²/kg and a hydraulic activity of at least 1500 mg/g and metakaolin with a grinding degree of at least 2000 m²/kg and a hydraulic activity of at least 1200 mg/g and sodium methylsiliconate GKZH-11N with the following content of components, wt.%: Portland cement - 20.0-22.0, sand - 59.4-63.0, MasterRheobuild 183 superplasticizer - 0.20-0.22, finely ground pozzolanic component - diatomite - 2.0-2.2, finely ground pozzolanic component - metakaolin - 2.0-2.2, sodium methylsiliconate GKZH-11N - 0.010-0.011, water - 12.790-13.969.

EFFECT: reducing the consumption of Portland cement and superplasticizer in the concrete mixture, increasing the dimensional stability and ensuring the absence of defects in the form of ruptures of printed layers from the concrete mixture with the possibility of its extrusion on building 3D printers that implement the layer-by-layer extrusion method, reducing shrinkage deformations, water absorption, increasing the flexural strength of the hardened composites printed on a 3D printer (without the use of molds).

1 cl, 2 tbl