MODIFIED CONCRETE MIXTURE FOR 3D PRINTER EXTRUSION Russian patent published in 2022 - IPC C04B28/04 

FIELD: construction materials.

SUBSTANCE: invention relates to the field of construction materials industry and can be used for the manufacture of building products and structures in additive manufacturing technology by layer-by-layer extrusion (3D printing) of a concrete mixture based on Portland cement, sand, finely ground pozzolan component, superplasticizer and polysiloxane ether. The modified concrete mixture for extrusion on a 3-D printer includes Portland cement, sand, superplasticizer and water. At the same time, Portland cement is 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, MasterRheobuild 183 based on naphthalene sulfonates is used as a superplasticizer, and additionally the mixture contains a finely ground pozzolan component: bio-silica with hydraulic activity of at least 1400 mg/g, grinding degree of at least 1100 m²/kg and polysiloxane ether MasterPel 793 with the following component content, wt. %: specified Portland cement 20.0-23.0, specified sand 61.75-65.20, specified superplasticizer 0.20-0.23, specified finely ground pozzolan component bio-silica 2.0-2.3, specified polysiloxane ether 0.010-0.012, water 12.590-12.708.

EFFECT: reducing the consumption of Portland cement and superplasticizer in the modified concrete mixture, increasing the shape stability and ensuring the absence of defects in the form of ruptures of printed layers from the modified concrete 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 a 3D printer (without using forms).

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