The study of cement mortars containing expanded vermiculite as a filler is presented. The use of vermiculite up to 30% or more leads to good thermal insulation properties of solution, but low compressive strength. Features of the nature of expanded vermiculite contribute to reducing the density and providing heat-shielding properties. Mechanical activation of binder compositions depending on the duration of treatment in a vibrating mill compositions: Portland cement 90-70%, vermiculite 10-30%, allow to obtain a density in the range of 1720-1933 kg/m3, with a strength of 42.8-58.2 MPa, while saving up to 10 - 20% of expensive energy-intensive cement. Cement stone from binder compositions is created due to the form ation of a spatial framework created by a porous mineral filler, which, due to its high dispersion, occupies a significant spatial volume and a crystalline structure is formed on this mineral filler, as on substrates, created by calcium hydrosilicates and hydroaluminates. It builds up a secondary framework with crystalline neoplasms on finely dispersed vermiculite grains - plates. The developed binder has a porous structure due to the introduction of vermiculite filler, which reduces the thermal conductivity of the created composite. The use of the resulting binder compositions prepared from a mixture of Portland cement and vermiculite, in combination with a porous filler - expanded vermiculite, allows obtaining a heat-insulating mortar with high heat-shielding performance and guaranteed strength
Introduction. Mixing of dry components in mixers is one of the most important stages of any technological process in the manufacture of a composite material. To date, various technologies use a wide variety of mixing equipment, which is characterized by different principles of mixing and design solutions. Of particular interest for the preparation of high-quality and homogeneous mixtures for heat-insulating purposes is a pneumatic mixer with a spiral energycarrying tube. The article presents the results of studies using the method of mathematical planning of the fullfactor ПФЭЦКРП24 experiment, which makes it possible to most adequately assess the ongoing processes while minimizing systematic errors.Materials and methods. In the work, ЦЕМ 0 42,5Н ГОСТ 31108–2020 Portland cement with a specific surface area of 308 m2 / kg, sand of the Volsky deposit were used as raw materials for testing. Expanded vermiculite obtained as a result of heat treatment of natural vermiculite at a temperature of about 700°C was used as a light filler.Results. Heat-insulating mixtures prepared in a pneumatic mixer with a spiral energy-carrying tube ensure the production of heat-insulating mortars with stable density values of 1420 kg/m3, having sufficient compressive strength of 3.3 MPa, and guarantee high heat-shielding properties in building structures.Conclusion. The developed design and the conducted studies made it possible to establish the high efficiency of the proposed mixer, which provides a uniform distribution of the particles to be mixed, high homogenization and the creation of conditions for accelerating the physicochemical interactions in the created mixture with subsequent mixing of the prepared mixture with water and the formation of the required internal structure of the created composites.
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