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

FIELD: construction materials.

SUBSTANCE: invention relates to the field of the construction materials industry and can be used for the manufacture of building products and structures in additive manufacturing technology using layer-by-layer extrusion (3D printing) of a raw mixture based on Portland cement, sand, finely ground pozzolan component, superplasticizer and sodium methyl silicate. The raw cement-based mixture for 3D construction printing includes Portland cement, sand, superplasticizer and water. Portland cement contains, wt. %: tricalcium silicate 68.1, tricalcium aluminate 7.2%, quartz sand with a size modulus of 2.2-2.4 and a moisture content of 1-2% is used as sand, Polyplast SP-1 is used as a superplasticizer: an additive based on sodium salts of polymethylene naphthalene sulfonic acids and additionally the raw mixture contains a finely ground pozzolan 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, as well as sodium methyl silicate “GKZH-11N” with the following component ratio, wt. %: specified Portland cement 20.0-22.0, specified quartz sand 59.56-63.15, superplasticizer Polyplast SP-1 0.20-0.22, specified diatomite 2.0-2.2, specified metakaolin 2.0-2.2, sodium methyl silicate “GKZH-11N” 0.010-0.011, water 12.640-13.809.

EFFECT: reducing the consumption of Portland cement and superplasticizer in the raw material mixture, increasing shape stability and ensuring the absence of defects in the form of ruptures of printed layers from the raw material mixture with the possibility of its extrusion on construction 3D printers implementing the method for layer-by-layer extrusion, reducing shrinkage deformations, water absorption, increasing the bending strength of hardened composites printed on 3D-printer (without using forms).

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