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  • Features of the deformation analysis of three-layer reinforced concrete slab structures

    The article presents proposals for the calculation of three-layer reinforced concrete slab structures, the outer layers of which are made of heavy concrete, the middle layer is made of lightweight expanded clay concrete. Experimental elements were calculated according to the compiled program of iterative calculation, which takes into account the concrete deformation diagram in an explicit form. The calculation program reflects a technique that allows you to determine the actual distribution of deformations in sections with a crack and in the areas between them. The results of the calculation of the prototypes indicate a close convergence of the theoretical values ​​of the breaking moments, deflections, deformations of the extreme fibers, and cracking forces with those directly recorded in experimental studies.

    Keywords: concrete, reinforced concrete, expanded clay concrete, reinforcement, three-layer slab, prestressing, calculation methods, deformations, stresses, deflections

  • To the determination of the relative deformation of reinforced concrete εb3 of compressed reinforced concrete flexible columns strengthened with composite materials located in the transverse direction

    The article provides data on the influence of external composite reinforcement of reinforced concrete compressed elements on their deformative properties. It was found that the deformations of reinforced samples, found according to the current standards, have significant discrepancies with the experimental values. Based on the analysis of the results of experiments, proposals were made to the methodology of norms for calculating the ultimate compressive deformations of concrete εb3, which take into account the type and percentage of composite reinforcement and ensure a good agreement between the experimental and theoretical values.

    Keywords: concrete, reinforced concrete, composite material, carbon fiber reinforced plastic, external reinforcement, deformations, compressed elements

  • New developments in housing construction abroad Part I

    Development is a necessary component of the processes taking place around us, without which it becomes impossible to improve the quality of our lives. In this article, we will focus on innovations in construction, but only those that are not just an innovation, but rather a necessary component that allows you to bring the process and economy of construction to a higher level, and, simply put, are the engine of development of the industry. So, let's look at a few innovations that, when used in mass production, can significantly simplify, speed up and reduce the cost of building construction.

    Keywords: construction, innovation, 3D printing, modular construction, innovative bricks, concrete, plastic, hybrid structures, wood, hollow elements, plastic, composite sleepers, foundations, cladding, aluminum, ceramics, green construction, eco-floating houses

  • The dependence of the bearing capacity on the class of concrete on the example of flexible reinforced concrete columns with combined reinforcement

    The search for the most efficient and cost-effective materials and structures is an important and urgent task. Reducing steel consumption can significantly affect the cost of structures, and the use of high-strength steel is one such method. Currently, there is great interest in reinforced concrete structures, which contain various combinations of pre-compressed, pre-tensioned and non-tensioned reinforcement. To determine the dependence of the bearing capacity on the class of concrete using the example of flexible reinforced concrete columns with combined reinforcement, a numerical experiment was performed. The performed numerical experiment showed the feasibility of using combined reinforcement - all the racks considered in the experiment with combined reinforcement are more effective than racks with non-tensioned reinforcement. At the same time, depending on the relative eccentricity of external forces and flexibility, it is necessary to choose the most effective type of combined reinforcement.

    Keywords: column, combined reinforcement, prestressing, flexibility, reinforced concrete

  • On the development of an energy-cooling system for the complete isolation of a special fortification

    The types of Autonomous stationary energy-cooling systems designed for complete isolation of special objects operating without connection with the atmosphere are Considered. A technical solution is proposed that allows increasing the efficiency of the energy-cooling system, reducing the consumption of process water due to its partial recirculation for cooling the engine of an Autonomous power plant, as well as increasing the period of complete isolation of the object.

    Keywords: energy-cooling system, underground facility, military infrastructure, complete isolation mode

  • Determination of intensity of movement of motor roads of local importance, located on the Factory highway in Samara

    The problem of major repairs on the factory highway in Samara still remains unresolved, although the issue has been acute for many years. During this time, as statistics show, there were a lot of accidents and damage to vehicles. A heavy load on the roadbed leads to rapid wear of the asphalt surface, as a result, almost every year the Factory highway needs repairs. The load on the highway will increase even more when the section of road connecting the new Kirovsky bridge with the Zavodsky highway is built. The automobile road in Samara along the ZAVODSKOE highway needs major repairs for several years, but the work does not begin, and every spring its condition worsens more and more. The issue remains relevant today.

    Keywords: automobile road, ZAVODSKOE highway, traffic intensity, climate zone, engineering and geological conditions, major repairs

  • Development of a polymer composite dielectric material based on epoxy resin

    This study presents the results of the development of a polymer composite material with good dielectric properties, which allows it to be used in the radio and electrical industries. This material is based on epoxy resin, polyethylene polyamine, hollow glass microspheres and gallium oxide. The use of hollow glass microspheres in the composition in an amount of 5-20 wt. h. reduces the dielectric losses, and the use of gallium (III) oxide in an amount of 5-15 wt.h. it makes it possible to increase the stability of the dielectric characteristics when working in the microwave radio range and reduce the dielectric loss. Studies have shown that a sufficiently effective composite polymer material with high physical, mechanical and dielectric properties can be obtained on the basis of the developed composition.

    Keywords: composite material, epoxy resin, hollow glass microspheres, gallium oxide, permittivity, dielectric loss tangent

  • Calculation models of steel frame assemblies for multi-storey buildings

    The article considers the calculation of the node of the frame of a multi-storey building. A comparative analysis of the work of potentially used materials is performed. The optimal cross sections of I-beam elements used in the node are selected.

    Keywords: node, frame, multi-storey building, I-beam, calculation, method of limit States, calculated resistance, load, cross-section, material

  • The strength of reduced and strengthen reinforced concrete for cover plates

    The method of plasma treatment of concrete's fillers, that increasing service properties building materials. We have studied influence different industrial repair cement compositions to the strength of reduced and strengthen reinforced concrete for cover plates for civil engineering. This was shown, that external reinforcing of repaired layers by carbon fiber networks increase significantly their load-carrying capacity. Using epoxy-based covering mortar is the most efficiency.

    Keywords: internal reinforcement, low temperature plasma, composite materials, building cover plate

  • Optimization sizes of steel vertical tank

    Storage of volatile and flammable liquids is carried out, as a rule, in vertical steel tanks. In total storage, they make up more than 80%. That is why research in this area is important in industry. The issue of reducing the cost of manufacturing tanks and reducing material costs during construction is extremely relevant. Based on the dependences of the optimal diameter, height and mass of the hull on the volume of the vessel, calculations were made for the existing TVS-10.000. In this paper, we considered a method for optimizing the size of a tank from the condition of minimum material consumption of the housing.The main dependencies and formulas were derived, on the basis of which the calculation was performed. When making calculations, the effect of static load was taken into account without the influence of dynamic factors. Thus, there was a decrease in material costs by about half for the cylindrical wall, cover and bottom.

    Keywords: vertical steel tank, important in industry, reducing manufacturing costs, reducing material costs, optimizing sizes, method of optimizing sizes, minimal material consumption

  • Development of a composite heat-resistant polymer dielectric material

    This paper presents results of development of heat-resistant dielectric composite material based on epoxy resins to create structural and electrical radio products, coating materials receiving and transmitting radio systems for the aerospace, naval and land equipment. Research results show that when adding 10 wt.h. polyethylene polyamine as a hardener, 10-30 wt.h. polymethylphenylsiloxane as a modifier to ensure homogeneity, 10-40 wt.h.ceramic hollow microspheres and 5-15 wt. h. alumina as fillers per 100 wt. h. epoxy resin can be obtained a material with low permittivity and high thermal stability at 150 °C.

    Keywords: dielectric material, polymer binder, epoxy resin, polyethylene polyamine, polymethylphenylsiloxane, hollow ceramic microspheres, heat resistance, permittivity

  • The study of room's air exchange scheme's influence on exhaust ventilation hood's effectiveness

    The study is set to determine room's air exchange scheme's influence on exhaust ventilation appliances' effectiveness. Open-type exhausts (exhaust ventilation hoods) used in different industrial manufacturing processes are selected. In particular, a food processing working space with an adjacent meat heat-treating chamber, where ventilation hood is installed near an open doorway, is evaluated. Two options of supply air ducts' installation (air inflow in the center of a working space or, alternatively, side areas of it) are analysed. Geometrical models of heat-treating chamber, raw material loading room, ventilation hood placed over chamber's door, and supply air duct with air-distributing appliances are constructed. The article presents results of numerical simulation for the model of heat-treating chamber's exhaust ventilation system operation. It is established that, in case of a supply ducts' installation in a side areas of a room, an air exchange could be lowered by 28% under condition of a removal of a gas-air mixture without breaching into the room.

    Keywords: exhaust ventilation, ventilation hood, simulation, heat-treatment chamber, numerical experiment

  • The dome construction of low-rise buildings with the use of polystyrene panels

    The article is devoted to the construction of domed buildings made of Styrofoam slabs. Positive aspects were noted in the construction and operation of domed buildings. The impact of snow, wind, and seismic loads on the dome building is estimated.

    Keywords: construction, building, domes, shaping, energy efficiency, load, snow, wind, seismic

  • Accounting for the seasonality factor in the architecture of hotels on the Black Sea coast of the Krasnodar Territory

    In the article, the authors consider the influence of the seasonality factor on the architectural and planning decisions of hotel buildings on the Black Sea coast of the Krasnodar Territory. The climatic and socio-economic conditions of this region are revealed. The operating modes of buildings dictated by climatic characteristics are determined. The optimal solution for this region is a year-round building with seasonal expansion. The authors describe the solutions of hotel rooms and public spaces, taking into account seasonal changes in capacity, purpose of the room, climatic and other factors.

    Keywords: seasonality, architecture, hotel, adaptability, recreation, transformation, design, mobility, climate, leisure

  • On the development of structural schemes for skeletons of high-rise monolithic reinforced concrete buildings

    This article raises the issue of designing high-rise monolithic reinforced concrete buildings. Possible applications of the main parts of the building frame to create the optimal structural scheme in accordance with the requirements for providing the building with stiffness, stability, resistance to external forces and resistance to deformations are presented. It also offers a modern method of structural analysis, which allows to ensure durability and all necessary conditions for the safe operation of the building

    Keywords: structural scheme, rigidity, stability, reliability, frame, load-bearing element, structural system, "flexible layout", wall systems, finite element method

  • Double layer wall panel from papatoetoe

    The compositions of class B15-20 peplotuf concrete on tuff ash and crushed stone with the use of a plasticizer for use as a structural and thermal insulation layer in two-layer wall panels are proposed. The calculated heat transfer resistance of a two-layer structure is determined, and the dependence of the density and strength of the mixture on the cement consumption per 1m3 is established.

    Keywords: tuff rubble, tuff ash, expanded clay concrete, peplotufobetonnaya mix, multi-layer wall panel, structural and thermal insulation concrete

  • Modern methods of building roads in marshy areas

    Often, during the construction of roads in a swampy area, difficulties arise from the adverse conditions of this biome. This becomes a serious problem both at the design stage and at the construction stage. In order for the road to stand the time allotted to it by the project, designers and builders often resort to non-standard solutions, solutions that are rarely used in other conditions. This article will discuss some of them that are most widely used, due to their reliability and effectiveness.

    Keywords: road, construction, design, swamp, peat, aggressive environment, geotextiles, geo-piles, concrete, asphalt concrete, retaining walls, armored ground

  • Rational designs of reinforced concrete slabs of frame-monolithic buildings in Mexico

    The article considers several types of reinforced concrete slabs: homogeneous monolithic slabs, waffle slabs, as well as prestressed joist and vault slabs. Its main characteristics, properties and advantages are also described. An evaluation of structural analysis is given with a determination of its effectiveness. Reticular slabs: they are made from a network of cross beams that form a grid, leaving gaps that can be filled with blocks of materials whose density does not exceed 900 kg / m3. Homogeneous monolithic slab: it is a slab composed of concrete and reinforcement. The rebars are located in both directions, according to the characteristics of the load. Prestressed joist slabs and vault: it is a structural system consisting of precast beams that are made of prestressed concrete and include hollows of various configurations, within which lighting elements can be placed.

    Keywords: concrete, reinforcement, reinforced concrete, floor slabs, wafer plates, monolithic plates, precast monolithic plates

  • Experimental study of the work of a reinforced concrete floor slab under punching by column

    A brief analysis of dependencies for calculating the punching of reinforced concrete slabs used in domestic and foreign design standards is presented. The results of an experimental study on experimental samples of the strength of a monolithic floor slab with a central punching by column of square and rectangular cross-sections are presented. Comparative analysis of experimental and calculated values of destructive loads showed a significant excess of the calculated values for the sample with a rectangular column. The observed excess of the calculated values of destructive loads over the experimental values is due to the presence of features of the stress-strain state in the zone of punching for rectangular columns. The excess of the calculated value of the destructive load over the experimental value noted during tests indicates a decrease in the structural safety of such interface nodes in the monolithic girderless frame of buildings.

    Keywords: reinforced concrete, monolithic girderless frame, punching, loading platform, prototype, destructive load, prismatic strength, deformation, strain gauge

  • Some organizational and technological solutions for the construction of foundations for the construction of man-made territories

    The expansion of urban space is carried out through the construction of modern multi-storey buildings located mainly on vacant sites along the perimeter of the existing urban area. It often happens that such sites were previously exposed to various man-made impacts. At the same time, man-made impacts can affect engineering and geological conditions, impairing the natural physical and mechanical properties of the bases. An example is the arrangement of various types of landfills, the movement of the soil and vegetation layer, and the artificial change in hydrogeological conditions. The construction of foundations on such soils is more complex than in normal conditions. The bearing capacity of the bases is reduced, and the geological strata are heterogeneous. The design of foundations requires the fulfilment of calculations, taking into account the above factors. The subsequent implementation of the project requires higher financial and time costs for the preparation of the bases and the construction of foundations, compared with the construction of similar buildings in conditions not previously affected by man-made effects. The article provides examples of the construction of foundations on an artificial basis, in the construction of modern multi-storey residential buildings on the territory of the former aeration fields in Lyubertsy. The results of the work are given and analyzed. The results of the study can be useful in the design and subsequent construction of modern buildings in similar conditions.

    Keywords: Foundation, soil, Foundation, sediment, monitoring, construction

  • Comparative analysis of the effectiveness of various types of overhead natural lighting systems in public and industrial buildings

    The article deals with the comparative analysis of traditional and new types of lighting systems in multistory public and industrial buildings. The analysis is being conducted with use of some specific objective and subjected criteria. These include a number of design characteristics of the systems in question – from an overall cost of the installation to the psychological contact with the outdoor environment. It is noted, that the main characteristic of a human activity is productivity and this depends upon the working conductions, which are evaluated on the basis of subjective appraisal. The best solution of the system of natural lighting, according to the number of criteria considered, which matches the above requirements is the system of lighting wells, combined with the windows.

    Keywords: the system of roof natural lighting, objective and subjective appraisal, comfort of indoor environment, evaluation criteria, public and industrial buildings

  • Verification of the electronic model of the thermal network by "equivalent absolute roughness"

    The article substantiated the need to create electronic models of heating systems using BIM and GIS technologies. It is indicated that the original model data is needed correctly. The theoretical basis for determining the specific drop in pressure in thermal networks is given and its functional dependence on the size of the equivalent absolute roughness of the pipeline walls is established. The dependence of the change in the equivalent absolute roughness on the life of the pipeline is given. References to literature containing the most complete base of values equivalent to absolute roughness are given. A combined hydrometric graph of the hydraulic heating system modes at different values of the equivalent absolute roughness is given. Recommendations for verification of the electronic model have been given.

    Keywords: electronic model, hydraulic mode, pressure drop, heat carrier, hydraulic friction factor, equivalent to absolute roughness, verification

  • Estimation of the time factor in technical systems on the example of manufacturing products of heavy and nuclear engineering

    In this paper, the time of manufacturing of nuclear industry products is estimated depending on the complexity of technological operations, the time to justify the choice of manufacturing options, and the performance of mandatory research and development work . The time factor as an element of the system of technical progress is presented on the practical example of replacing heavy Metalworking equipment with mobile small -sized units.

    Keywords: time factor estimation, shell, steam generator, roller stands

  • Simulation of manifold penetration under the active motorway

    The article deals with the issue of modeling by the finite element method of the penetration of the communication tunnel under the operating multi-lane highway demand microtonneling, horizontal directed drilling and construction under the protection of the screen from pipes

    Keywords: Tunnel, collector, finite element method, microtonneling, horizontal directional drilling, motorway, case, reinforced concrete, metal pipes, settling mule

  • On the issue of calculating the reinforcement in the junction of a beamless monolithic plate with a column

    The article discusses the results of the calculation of reinforcement in monolithic reinforced concrete floors. The subject of the study is the reinforcement of the slab section located next to the column. The study was carried out by setting up a computational experiment. Modeling was performed in software systems: Revit, Sapphire and Lira-CAD. Finite element models were calculated in Lira-CAD software. A total of 7 series of samples were calculated. The samples are a fragment of a monolithic reinforced concrete floor of a civil building. Investigated factors: triangulation parameters; the presence or absence of absolutely rigid bodies in the node. The authors performed a comparative analysis of the results of a computational experiment. It was found that for the most correct and economical selection of reinforcement in models without the use of AFL, it is desirable to take the triangulation step in the slab equal to the side of the column section or more than this value by no more than 15%, since an increase in the size of the finite elements leads to an underestimation of the reference moment and the resulting area calculation longitudinal working reinforcement. With this approach, the value of the maximum moment, and, therefore, the area obtained by the calculation of the reinforcement will be 6% higher, which makes it more preferable, although it increases the complexity of creating a finite element circuit.

    Keywords: BIM technology, reinforced concrete, girder-free overlap, reinforcement, triangulation, finite element, reinforcement selection, computational experiment, Rewit, Sapphire, Lira-CAD