MIXTURE FOR PRODUCING DECORATIVE COMPOSITE IN PREDETERMINED COLOUR SCHEME IN CONSTRUCTION 3D PRINTING TECHNOLOGY AND METHOD FOR PRODUCTION THEREOF

摘要

FIELD: additive manufacturing technology.;SUBSTANCE: invention relates to the field of production of building materials adapted to the technology of construction 3D printing and exhibiting architectural expressiveness. The mixture for producing a decorative 3D-printing composite consists of dry components and a liquid grouting agent at the ratio thereof of 7.54 to 7.58:1, the ratio of the dry components of the mixture (% wt.): portland cement CEM I 42.5 N – 43.10 to 43.48, sand with a fineness modulus Mf ≤ 1.25 – 53.35 to 53.89, metakaolin with a content of SiO2 of no less than 53% and Al2O3 of no less than 47 % – 0.855 to 0.866, red powder pigment based on Fe2O3 with a content thereof of no less than 96.1%, or green based on Cr2O3∙2H2O + Fe2O3 with a content of Fe2O3 of no less than 26.1 % – 1.304 to 2.155. The liquid grouting agent comprises the following components at the mass ratio thereof (%): water – 95 to 95.2, superplasticiser based on polycarboxylate esters – 3.2 to 3.3, polypropylene fibre – 1.6 to 1.7. The method for producing a decorative mixture consists in the fact that the components of the solution are mixed together in predetermined ratios and in a certain sequence, first, dry components are mixed in a high-speed rotary mixer for 1 to 2 minutes: portland cement, fractionated filling aggregate (quartz sand), a viscosity modifier additive – metakaolin; simultaneously, the liquid grouting agent is prepared – water is mixed with a superplasticiser based on polycarboxylate ether in a separate container, introduced whereto directly prior to application is the reinforcing component – polypropylene fibre; the solution is added to the dry components, the resulting mixture is mixed by a high-speed rotary mixer for 3 to 5 minutes. In order to produce an item in a predetermined colour scheme, two methods for introducing a pigment are possible: the first method – the powder pigment of a certain color is introduced into the mixture of dry components to produce a composite coloured uniformly throughout the volume; the second method – the powder pigment is introduced directly into the mixer 10 to 15 seconds prior to the end of mixing to produce a composite coloured differentially throughout the volume.;EFFECT: production of a 3D-printing mixture for a decorative volume-coloured composite in a predetermined colour scheme with high operational characteristics, exhibiting plasticity and shape stability.;2 cl, 1 tbl