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<p>We have carried out studies on the production of low-clinkered floured cements (LCFC) on the basis of natural and technogenic waste. The research on optimizing the compositions, strength, durability and performance properties of low-clinkered floured cements (LCFC) was carried out. Therefore, we studied the new products in the process of hydration of mechanically activated multi-component cements in the presence of technogenic wastes of the industry (waste of limestone crushing at opencast mines, metallurgical and phosphoric slag) and surface-active reagents (SAR) (superplasticizer S-3); as well as the development of compositions of high-strength and technological sorts of cement concretes. Thus, the low-clinkered floured cements developed by us based on industrial technogenic waste that meet the modern requirements, i.e. they improve physical-mechanical characteristics of the material and positively influence the ecological situation and allow decreasing the cost of final product. The physico-chemical research of the processes of hydration of low-clinkered floured cements with additive of superplasticizer S-3 were carried out by modern methods using X-ray diffract-meter D8ADVANCE (Bruker company) with Cu-radiation and synchronous thermo-analyzer STA 409 PC Luxx (Netzsch, Germany) at exposure mode of 10 º/min in the platinum crucibles in the air conditions.</p>

This article presents the results of production experiments to optimize the modes of silicon smelting in an industrial arc furnace. The main factors of the melting process are the size of the fractions of the charge components and the temperature regime of heating. The rate of charge heating in the reaction zone in the temperature range from 950 to 14100C has a special effect on productivity. In this temperature range, the formation of refractory silicon carbide on pieces of quartzite was established, which causes a drop in the magnitude of the electric current in the reaction zone and its freezing. The gornisage, which is formed, displaces the electrodes into the zone of greater charge electrical conductivity - up, which leads to an increase in silicon monoxide emissions through the reduced charge layer. Correction of such a process requires an increase in the temperatures in the reaction zone and the duration of the melt. A method has been developed for calculating the size of quartzite fractions, depending on the power of the furnace and the size of the reaction zone. An example of a simplified calculation is proposed.

В работе приведены результаты исследований по проектированию составов мелкозернистых бетонов на напрягающем цементе для замоноличивания стыков труб. Задачей исследования явилось получение материала заделки стыков с заданными физико-механическими свойствами. Для этого были определены оптимальные составы мелкозернистых бетонов на напрягающих цементах и условия получения материала, удовлетворяющего требованиям, предъявляемым к бетонам заделки стыков бетонных труб, закрытых водоподающих систем. Исследования проводились на экспериментальных установках. Установлено, что мелкозернистые бетоны на основе напрягающегося цемента обладают особо плотной структурой, обусловливающей их высокую непроницаемость, также повышенную трещиностойкость благодаря наличию в них самонапряжения. Высокая непроницаемость обусловлена его слабо пористой структурой, округлой изометричной формой пор, отсутствием неплотностней между заполнителем и цементом. Исследованиями установлено, что путем изменения водоцементного отношения, расхода напрягающего цемента и песка можно регулировать структуру напрягающего бетона. The paper presents the results of studies on the design of compositions of fine-grained concrete on tensile cement for monolithic pipe joints. The objective of the study was to obtain material for sealing joints with specified physical and mechanical properties. For this, the optimal compositions of fine-grained concrete on tensile cements were determined from the conditions for obtaining a material that meets the requirements. Presented to concretes for sealing joints of concrete pipes of closed water supply systems. The studies were carried out in experimental facilities. It was established that fine-grained concrete based on tensile cement has a particularly dense structure, which determines their high impermeability, as well as increased crack resistance due to the presence of self-stress in them. High impermeability is due to its weakly porous structure with a rounded isometric pore shape, the absence of leaks between the aggregate and cement. Studies have found that by changing the water - cement ratio, the flow rate of the cement and sand, the structure of the concrete can be adjusted.

The article presents the outcomes of analysis and synthesis of Russian and Kazakh researches on the issue of the use of industrial waste industry for the production of composite slag base binders and concretes. Utilization, liquidation of industrial wastes and their use in the production of composite alkali-activated slag are the issues of global and national importance. Therefore, industrial and developed countries pay great attention to this issue. The influence of the production wastes of the enrichment of polymetallic ores – carbonate-barium tailings on the performance properties (strength, water absorption, density, etc.) of composite alkali-activated slag and concretes is studied. The ways of introducing modifying additives “waste of carbonate-barium tailings” into the composition of alkali-activated slag and concretes are investigated. The optimal amount of introduction the waste of carbonate-barium tailings into the composition of alkali-activated slag of modifying additives is determined. It is 10% of the binder mass and an indicator of effectiveness in influencing the activity of concrete, depending on the type of alkaline component and the hardening conditions. The methods of testing the experimental work to determine the operational properties of alkali-activated slag and concretes based on them are presented.