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Development of Alkali-activated Binders based on Technogenic Fibrous Materials

https://doi.org/10.58224/2618-7183-2023-6-1-60-73
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 60-73 p.
Abstract
The paper discusses the development of alkali-activated binders based on technogenic fibrous materials. An approach to the secondary use of technogenic fibrous materials as a filler of composite binders is offered. The properties of mineral wool waste have been established. The microstructure of finely ground fibrous particles has been studied. Compositions of alkali-activated binders were de-veloped, when grinding basalt insulation production waste to a specific surface of 300-330 m2 /kg, followed by the formation of a binder according to the first method with rod tamping sealing and, ac-cording to the second, by pressing a raw binder mixture at a pressure of 10 MPa. The developed com-positions of alkali–activated binder by pressing with a compressive strength of 22.8 MPa, and when compacted with subsequent rod tamping – 11.8 MPa.
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Сompositional analysis: the project of the III Communist International Monument (Tatlin Tower)

https://doi.org/10.58224/2618-7183-2023-6-1-74-83
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 74-83 p.
Abstract
The authors of the article broadcast information about the study of the compositional activity of architects of Soviet Russia in the 20s of the XX century. in line with the trend of "constructivism". The study of three-dimensional architectural composition is considered by the authors as the separation of the "indivisible whole" (integrity – the law of composition) and "unchangeable for further im-provement" (it is impossible to make changes without deterioration of the already created, completed composition) artificially created object – organism of universal laws and means. The authors believe that the study of high–class Heritage samples is based on the separation of formal (composite) ele-ments (contrast, plastic, texture, plane – volume, rhythm, modular divisions, construction, engineering materials, walls, floors, ceilings, fasteners, etc.) from an artificially created composite organism. The analysis allows you to develop compositional thinking, taste and teaches you to understand the course and origins of the Master's compositional thought. The study of the formal (compositional) sphere of the Heritage of the classics of modernity and past eras allows you to build the path of the author's work on the project, avoiding mistakes and disappointments.
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Reinforcement of construction of underground structures with shotcrete

https://doi.org/10.58224/2618-7183-2022-5-6-5-18
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 5-18 p.
Abstract
An urgent scientific task, which is of great practical importance for increasing the defense capability of the state and preserving the population, is the improvement of constructive methods for the complex repair of underground structures. Reinforced shotcrete concretes have been developed and their research has been carried out to strengthen underground structures. Achieving the uniform workability of shotcrete (slump 19 cm) was carried out by varying the dosage of the superplasticizer, which has a high water-reducing ability (40%). Some reduction in slump flow (47 cm) was observed at a dosage of ACC in the amount of 35 wt. %. An increase in the density of the mixed mixture with an increase in the content of the aluminosilicate component in the polymineral binder was established. The introduction of the alumino-silicate component in small quantities (up to 25 wt.%) slightly increases the 28-day density of the cement paste (0.3-0.4%). With an increase in the dosage of ACC (up to 35 percent by weight), an increase in the density of 28-day-old samples was noted, which linearly raised with an increase in the amount of introduced aluminosilicates. The effect of increasing the compressive strength of shotcrete concretes on a polymineral binder increased with an increase in the dosage of ACC up to 35% by weight, and the maximum effect is noted for early strength values, in particular, at the age of 1 day, an increase in compressive strength by compared with the composition without additives was 56%, and with bending 62%. This is also confirmed by the high ratios of the values of strength properties in the first day to similar indicators in the grade age: for compressive strength 0.27 (0.23 for clinker compositions without additives), for bending strength 0.30 (0.26 for additive-free clinker compositions). Theoretically and practically proved the effectiveness of the use of the developed shotcrete for strengthening the supporting structures of underground structures with an increase in strength of more than 2 times, which is explained both by the high strength of the obtained repair composition and the monolithic contact zone between the old and new layers of concrete. The developed shotcrete is able to provide the necessary degree of strengthening of the supporting structures of underground structures, while the thickness of the repair layer of 6 cm (with proper soil fixation) allows the use of underground structures as dual-use facilities.
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Technological Solutions Ensuring Reliable Operation of Steel Vertical Reservoirs in Seismic Areas

https://doi.org/10.58224/2618-7183-2022-5-5-5-16
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 5-16 p.
Abstract
The article discusses the relevance of reliable operation of vertical steel reservoirs (RVS) in earthquake-prone areas. Based on the analysis of a number of scientific publications, it has been estab-lished that for the safe functioning of large–sized RVS, it is necessary to install anchor devices, the main purpose of which is the transmission of vertical forces arising from an earthquake in the wall to the base. To do this, they must be securely fixed to the wall and the base in order to evenly distribute efforts across the office of the RVS. In some cases, poor-quality connection of the anchor with the RVS leads to significant stresses in the anchors and there is a possibility of both rupture of the housing itself and rupture of the connection of the housing with the bottom of the tank. It is known that large-sized tanks require a massive base and the installation of anchors with a large number of bolts is a very expensive undertaking.
The article discusses the most common variants of anchors that are used in practice, lists some of their disadvantages and suggests an improved version based on the analysis of scientific publications. The authors present their own development – a modified version of the anchor device, the corresponding design solutions are given and the technology of the device is described. In addition, it was noted the need to increase the bearing capacity of the soils of the RVS foundation, constructed in earthquake-prone areas using geocomposite materials. It is emphasized that the required number and length of an-chor devices, as well as the choice of geocomposite material for soil hardening should be justified by appropriate calculations. It is concluded that in order to ensure reliable operational characteristics of RVS located in seismically hazardous areas, the installation of anchors, despite attracting additional financial resources, is a prerequisite, since in the event of a spill of petroleum products, the restoration of biogeocenosis requires more than one decade and involves enormous material costs.
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Methods of storm water drainage from the roadway in flat urban areas

https://doi.org/10.58224/2618-7183-2022-5-6-19-31
 19-31 p.
Abstract
The research examines the issues of timely and efficient water drainage from the roadway in flat urban areas in the face of numerous forecasts of an increase in the intensity of precipitation intensity and the frequency of showers. The article considers the existing methods of water drainage using a “sawtooth” profile along the edge of the roadway. “Sawtooth” profile schemes were designed in accordance with the current regulatory documents. Unfavorable factors affecting the design and construction of this solution were noted. The article identifies and shows the problem pieces where the “sawtooth” profile method was used on the existing streets. A survey about the driving comfort on the streets with “sawtooth” profile was conducted and its result was shown. The study concluded about the expediency of changes the methods of water drainage from the roadway in flat urban areas. Recommendations were made on the need for changes in the current regulatory documents in order to improve the efficiency of water drainage during periods of increased moisture on the roadway without sacrificing the driving comfort.
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Social communications in architectural solutions in large office centers

https://doi.org/10.58224/2618-7183-2022-5-6-32-53
 32-53 p.
Abstract
In recent decades, the development of such industries as IT, the financial sector, consulting, and other professional services has led to an expansion of the so-called white-collar class employed in office jobs. There was a need to construct large office centers, both within and outside cities with transport accessibility. Companies are interested in comfortable office environments that ensure their efficient functioning, without overspending human and economic resources. Thus, office centers with comfortably organized environments have been in high demand in recent years both for expanding the staff and as investment solutions. The article’s purpose is to present the results of the study on the or-ganization of social communications in the architecture of large office centers (class A). As part of the study, the article analyzes the features of the general functional and planning organization of an office center, as well as the factors influencing the features of urban placement and the formation of the ar-chitectural and planning structure of office buildings. The resulting part of the study identifies the main groups of premises and spaces of office centers, as well as the main premises and spaces of office centers that provide for the organization of social communications. The article shows the features and techniques of the urban planning organization of office centers in terms of external social commu-nications and architectural and planning solutions for the organization of internal social communica-tions of office centers. As the results of the study showed, the concept of adhocracy management has been implemented in Russia. It is adjusted in accordance with the requirements of the time and market development and supported in office interiors by equally flexible planning of open spaces, which can change without significant additional investment in accordance with the needs of a corporation. On the other hand, closed premises have partially ceased to be universal. They are designed and equipped in accordance with the specified functions (meeting rooms, multimedia rooms, telephone booths).
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Consideration of dynamic impacts in the design of cantilever structures

https://doi.org/10.58224/2618-7183-2022-5-6-54-63
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 54-63 p.
Abstract
The article is devoted to the question of the influence of the constructive solution of cantilever structures on the indicators of rigidity and dynamic comfort of the building. The analysis of the influence of the solution of cantilever structures on dynamic indicators is carried out on the example of a building with a metal spatial frame having a cantilever part with a span of 22 meters. Two variants of the building frame were compared in terms of rigidity and dynamic comfort under wind and seismic influences. The calculations were performed in the certified software package "Lira-SAPR". A modal analysis was performed, the frequencies and forms of natural oscillations were determined, the maxi-mum acceleration of the overlap of the cantilever part of the building was determined. It is established that with constant metal consumption, increasing the height of the crossbars due to the use of through structures can significantly increase the rigidity of the system and provide the required indicators of dynamic comfort. Performing dynamic calculations at the stage of variant design allows you to choose the optimal variant of the structural solution of the building
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Compositional analysis: synthesis of abstract painting and architecture of the 20s of the XX century

https://doi.org/10.58224/2618-7183-2022-5-6-64-74
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 64-74 p.
Abstract
The authors broadcast information about the union of architecture and abstract painting and the identification, fixation of the laws and means of composition that were used in the creation of the well-known creative products of architecture, painting, design. The article analyzes the prerequisites for the emergence of an international style that easily integrates into any cultural environment, historical buildings, due to the presence in the products of this direction of the maximum formal sphere and almost complete leveling of the content part in an artificially created compositional form. The study of high-class Heritage samples allows you to develop taste and teaches you to understand the course and origins of the Master’s compositional thought. The study of the formal (compositional) sphere allows you to build the path of the author's work on the project, avoiding mistakes and disappointments.
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Plasma electrolyte production of titanium oxide powder

https://doi.org/10.58224/2618-7183-2022-5-6-75-84
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 75-84 p.
Abstract
The work is devoted to the research of plasma-electrolyte process realized in conditions of cathodic polarity of active metal electrode and its immersion into electrolyte to produce titanium oxide micro- and nanoparticles as well as titanium oxide-coated particles up to 10 μm in size. Two modes of discharge combustion differing in heat generation and concentration of electrolyte solution on particle size distribution were found to influence. Voltage increase can result in discharge combustion in arc mode due to thermal emission of electrons and intensive heating of titanium cathode. This, in its turn, leads to formation of titanium particles up to 10 μm in size, which surface is oxidized. It was found that discharge combustion in the regime with less heat emission leads to formation of titanium oxide particles sized less than 1 µm. These powders can be used in additive manufacturing, powder metal-lurgy and as additives in composite materials.
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Structure and analysis of amorphous silicon dioxide nanoparticles

https://doi.org/10.58224/2618-7183-2022-5-6-85-94
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 85-94 p.
Abstract
One of the most common methods of studying as well as controlling the environment and production products is the method of chromatography. The main working element that separates components into components, in particular, is silicon dioxide powder of nano and micro sizes. At the same time powder materials are widely used and relevant for powder technologies of additive construction. The aim of the work is to study the structure and analysis of obtained nanoparticles of amorphous silicon dioxide, satisfying the characteristics for use in high-performance liquid chromatography columns, as well as in various additive technologies. Studies have shown that the method of introducing water vapor in the plasma chemical reactor of the installation for the production of amorphous silica significantly affects the presence of free hydroxyl groups. In the infrared spectrum of the product, which was caught at a distance of 2 meters the line 3750 cm-1 is absent. At a distance of 1 meter the intensity of the line as a reference with 100% value. When a small amount of NaCl was added to the briquette used in spraying, the intensity dropped by 50%. When removed 1.5 meters away, the intensity is 75%. It follows that in the hotter gas during rapid cooling more OH hydroxyl groups are formed on the surface of the aggregates, when moving away from the reactor i.e. cooling the outgoing gas OH groups are formed less.
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