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EXPERIMENTAL STUDY OF PUNCHING SHEAR OF UNBONDED POST-TENSIONED REINFORCED CONCRETE SLABS
Authors: T.R. Barkaya, A.V. Gavrilenko, V.V. Fedorov, P.V. Kulyaev
Abstract: In this paper there are results of a punching shear test of slab samples, which were modeling post-tensioned reinforced concrete floor slabs when they are punched by columns. Geometrical dimensions of slab samples and properties of used materials are listed as well. There were 4 series of samples which differed to each other by level of prestress. Load have been applied through stamps of several types, which have allowed to research different positions of tensioned reinforcement relatively to the punching pyramid. Obtained results are discussed. Recommendations, which compliance may allow to obtain positive effect in ultimate punching shear loads for unbonded post-tensioned slabs are given.
Keywords: reinforced concrete, unbonded post-tensioning, punching shear.
SAWBOBETONE ON MODIFIED CEMENT BINDER
Authors: V.V. Belov
Abstract: The article considers the principles of production of sawbobetone on cement binder modified with additives of soluble glass and ash of hydraulic removal of local CHP. The material based on the modified cement binder using local secondary raw materials: sawdust as a filler of sawdust and waste ash as a fine filler is effective in low-rise construction conditions.
Keywords: modified cement binder, woodworking wastes, soluble glass and waste ash additives, composition selection, mathematical experiment planning.
COMPARATIVE ANALYSIS OF THE EFFECTIVENESS OF PREFABRICATED MONOLITHIC OVERLAPS IN THE CONDITIONS OF NEW CONSTRUCTION
Authors: A.V. Brovkin, R.S. Tsybina, A.V. Krivozhina, T.R. Barkaya
Abstract: This article provides a comparative analysis of the effectiveness of the use of prefabricated monolithic overlaps in the conditions of new construction, due to the problem in the construction industry of the economic efficiency of the applied structures of slabs Rectorlight of floors.
Keywords: prefabricated monolithic overlap, monolithic overlap, calculation, efficiency, new construction.
TECHNICAL AND ECONOMIC ASPECTS OF SUBSTITUTION OF NATURAL CRUSHED BY SECONDARY CRUSHED IN THE PRODUCTION OF CONCRETE
Authors: Y.Y. Kuryatnikov
Abstract: With the use of secondary crushed stone of fraction 5–20 mm and secondary crushed stone-sand mixture of fraction 0–60 mm, obtained during processing of concrete scrap, concrete compositions of strength classes B7.5–B22.5 have been developed. Replacing natural crushed stone with a secondary one gives a noticeable economic effect when using it.
Keywords: secondary crushed stone, secondary crushed stone-sand mixture, concrete scrap, heavy concrete, processing of substandard products, improving the ecological situation.
ARCHITECTURAL ENVIRONMENT: SPACES, TERRITORIES, LOCIS
Authors: V.V. Fedorov
Abstract: The structural organization of the city's architectural environment, including territories, spaces, and loci, is considered. It is shown that the architectural environment of the historical center of the city is characterized by special subject-spatial inclusions-loci of power. The complex dynamics of the interdependence of social existence and the architectural environment determines the relevance of studying the interaction of the locus (architecture) of power and society. The basic features of the architecture of power are considered: sociotechnical character, features of functioning, orderliness of the structure. The author analyzes the advantages and social significance of the power architecture, the latent features of the functional structure, the diachrony of compositional properties and the principles of ensuring closeness. The potential influence of power using architecture semantics is correlated with the processes of implementing algorithms for habitation, distribution, and dominance. The transformation of the status of the architectural space of power is considered not only as an architectural and planning transformation, but also as a change in its semantics and attitude to it. It is argued that the conceptualization of the locus (the assertion of authenticity) is converted into the popularity, influence, and economic growth of the locality. The social significance of loci of power is in their ability to subject-spatial modeling of social reality; in the formation of the potential for relieving social tension; in prompting the behavior of social actors in non-standard situations. It is noted that modern spaces of power are characterized by a gradual rejection of traditional closeness in favor of simulated openness. It is stated that the image of the architectural space of power is one of the angles of the socio-historical portrait of power.
Keywords: city, architectural environment, territory, space, locus, transformation of loci of power, sociosemiotics of architecture.
ECOLOGICAL MOUNTAIN AND TOURIST COMPLEX OF THE NORTH CAUCASUS
«U PODNOZH'YA VYSOT “ZORKIJ”»
Authors: S.V. Cheremnykh
Abstract: The article discusses one of the most optimal options for the development of mountainous areas – the formation of an environment for the development of entrepreneurial activity based on the creation of tourist complexes. The Chechen Republic is replete with numerous cultural monuments. However, no matter how beautiful the nature of the wild is, the area mastered by people must develop. This can be achieved by providing employment for the able-bodied population, which is an integral component for the economic development of the Republic and Russia. Taking into account the specifics of mountainous areas, it is necessary to adopt a set of measures for the development of mountainous areas, including based on the experience of other countries
Keywords: core system, metal constructions, wind power plants, solar modules, batteries, energetics, modular design.
RECONFIGURATION OF EXISTING ELECTRIC NETWORK OF URBAN TERRITORIES BASED ON POWER CONSUMPTION DATA
Authors: K.B. Korneev, Raymond Osei-Оvusu
Abstract: The problem of reliable and efficient power supply to municipal consumers can be solved by modeling and prognostic planning of consumption centers development. Analysis of statistical and forward-looking information allows planning of intra-city power supply network, identifying of emerging consumer clusters, and pursue an energy-saving policy in relation to distribution networks.
Keywords: power supply industry, transformer substation, planning, clustering, modeling.
INFLUENCE OF THE HEIGHT OF THE SLAG LAYER ON THE EFFICIENCY OF ARCS AND ELECTRICITY CONSUMPTION IN EAF
Authors: A.N. Makarov
Abstract: Investigated the influence of the height of the slag layer in the nomenclature row EAFs, with a capacity from 0.5 to 120 tons, on the efficiency of arcs and specific power consumption in the furnaces. It was found that with an increase in the height of the slag layer, the efficiency of arcs in low-tonnage and heavy-duty furnaces increases and reaches 78…80 % when the arcs are completely immersed in the slag, and the specific power consumption decreases. With an increase in the height of the slag layer and an increase in the efficiency of arcs by 1%, the specific power consumption in the furnaces decreases by 0.75…1.0 %.
Keywords: еlectric arc, steel, furnace, heat exchange, energy saving.
INFLUENCE OF CAPACITANCE, DISTANCE FROM ARCS TO WALLS ON THE EFFICIENCY OF ARCS AND ELECTRICITY CONSUMPTION IN EAF
Authors: A.N. Makarov
Abstract: The influence of the distance from the arc to the walls in the entire nomenclature row of arc steelmaking furnaces with a capacity of 0.5 to 120 tons on the efficiency of the arcs and the specific consumption of electricity in the furnaces was investigated. In low-tonnage EAF, the arcs are close to the walls and the efficiency of the arcs is small and amounts to 30…35 %, and the specific electric power consumption for melting is 650 kWh/t. In heavy-duty EAF, the arcs are located far from the walls, the arc efficiency is 46…49 % in the absence of a slag layer, and the specific electric power consumption for melting is 375…385 kWh/t.
Keywords: еlectric arc, steel, furnace, heat exchange, energy saving.
MAGNETIC FLUX SCATTERING IN TRANSFORMERS
Authors: I.P. Popov
Abstract: Existing methods do not allow measuring leakage reactance for each transformer winding separately, therefore, for simplicity, they are often assumed to be equal to each other. The purpose of the study is to substantiate the possibility of experimental determination of leakage reactance for each transformer winding separately. The dissipation reactance of each transformer winding separately can be determined by at least three experimental methods that give satisfactory agreement of the results. An almost paradoxical result – the capacitive nature of the leakage resistance of the inner winding of the transformer was obtained only for concentric cylindrical windings. It should not be generalized to other types of windings. The presented experimental methods are not tied to the character of the leakage resistance reactivity. They are universal - they can be used with any type of winding. The results obtained are recommended for use in the design and study of transformers.
Keywords: transformer, winding, dissipation, inductance, capacitance, flux linkage, magnetic flux.
ELECTRICAL SPECIFIC CONDUCTIVITY OF THE PRECIPITATION IN TVER
Authors: F.V. Kachanovsky
Abstract: Analysis had made of the precipitation′s electrical specific conductivity (atmospheric precipitation had fallen in Tver in 2016–2019 years). Time series models of the electrical specific conductivity and her evolution were examined. Cubic model has considered as adequate.
Keywords: сonductivity, acidity, acid rain, precipitation, model, time series, trend, cycle component, seasonal component, residuals.
EFFECT OF SODIUM CARBONATE ON THE HARDENING PROCESS OF THE PORTLAND CEMENT COMPOSITE
Authors: P.V. Kulyaev, A.V. Brovkin, R. Z. Tsybina, A.V. Gavrilenko
Abstract: The article enlightens a number of chemical transformations during hydration of Portland cement blended with sodium carbonate. Excess of ions CO3 in solution slows down the development of portlandite (calcium hydroxide) and provide intensive growth of calcium carbonate (calcite) crystals in hydrated cement, especially during the first day of hardening. It is shown that there are differences in strength between the solidified Portland cement mixture without and with the addition of Na2CO3. Soda modifies the procedure for the entry into the hydration reaction of the clinker components of the cement. With a certain increase in its content in the mixture, a slight increase in cubic strength for the dry-hardening specimens is also observed.
Keywords: sodium carbonate, hydration, cubic strength.