CONCRETE MIXTURE FOR EXTRUSION ON A 3D PRINTER 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. The effect is achieved by the fact that the concrete mixture for extrusion on a 3D printer includes Portland cement, sand, superplasticizer based on polycarboxylates and water. In this case, Portland cement was used, containing, wt.%: tricalcium silicate 68.1, tricalcium aluminate 7.2, quartz sand with a fineness modulus of 2.2-2.4 and a moisture content of 1-2% is used as sand, and superplasticizer is used "MasterGlenium 115" based on polycarboxylates, and additionally it contains a finely ground pozzolanic component - biosilica with a hydraulic activity of at least 1400 mg/g, a grinding degree of at least 1100 m²/kg and sodium methyl siliconate "GKZH-11N" with the following content of components, wt.%: Portland cement - 20.0-23.0, sand - 62.34-65.78, MasterGlenium 115 superplasticizer - 0.20-0.23, finely ground pozzolanic component - biosilica - 2.0-2.3, sodium methylsiliconate "GKZH-11N" - 0.010-0.012, water - 12.010-12.118.

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