| Summary: | ABSTRACT: Introduction. This article presents the results of the research works on formation of building gypsum plaster porous
structure with the use of recovered anhydrite raw materials and chemical additives, and describes a method for production of wall
materials. The relevance of this paper is stipulated by the need to expand the range and increase the manufacture of heat-insulating
and structural-heat-insulating products based on gypsum binders and local mineral raw materials, as well as the development of
technologies to ensure the production of gypsum materials with improved performance. The authors proposed certain methods for
forming the porous structure of building gypsum plaster and improving its performance in terms of porosity and thermal conductivity
through the use of modified recovered raw materials and chemical additives of calcium chloride and sodium carbonate. Materials
and methods. The study of the effect of modifying additives on the properties of the mixture was carried out using gypsum paste
of normal consistency (NC = 55%). The preparation of samples and testing were performed according to the methods specified
in the national standards with the use of porous additives of calcium carbonate, fluoroanhydrite and chemical additives for the
rheological properties of the mixture, average density and strength of the samples, the patterns and mechanism of the processes
of gypsum stone structure formation were established. Results. The application of fluoroanhydrite modified in the disintegrator
with an equimolar amount of calcium carbonate leads to a decrease in the average density of the samples to 40% with evenly
distributed pores. The analysis of the microstructure of heat-insulating material samples with a density of 550 kg/m3
showed that
the average diameter of micropores is 0.45 mm, while the thermal conductivity of samples with complex chemical additives has
the thermal conductivity coefficient of 0.25 W/m°C, which is 30% lower than the thermal conductivity of samples without complex
additives. Conclusions. The results obtained create the basis for using recovery raw materials and domestic modifying additives as
a pore-forming agent, which allow regulating the structure of gypsum stone in order to produce effective wall materials
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