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  • 1
    In: E3S Web of Conferences, EDP Sciences, Vol. 263 ( 2021), p. 01004-
    Abstract: In most high-strength concrete technologies, high-quality Portland cements are used, which is not always achievable in conditions of a shortage of such binders. The research’s purpose is to obtain high-strength concrete based on ordinary Portland cement of the M400 brand. To achieve this goal, the possibility of using the superplasticizer Conplast SP430 was studied. The research was carried out using standard methods, like using mathematical planning and result’s analytical processing. The implementation of the experiment allowed us to determine the optimal values of the basic composition of concrete: the consumption of superplasticizer-1.0 % of the mass of cement; the consumption of cement-485 kg/m3, the ratio of sand/crushed stone-0.36. At the optimal value of the parameters, the achieved maximum compressive strength was 58.8 MPa. The novelty is the justification of the possibility of obtaining high-strength concretes using Portland cement with an activity not exceeding 40 MPa based on the use of a new generation superplasticizer and the development of the basics of the method for selecting the composition of concrete. The significance of the result is due to the expansion of the possibility of using ordinary Portland cement for the production of products and structures with the use of high-strength concrete.
    Type of Medium: Online Resource
    ISSN: 2267-1242
    Language: English
    Publisher: EDP Sciences
    Publication Date: 2021
    detail.hit.zdb_id: 2755680-3
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  • 2
    Online Resource
    Online Resource
    Moscow State University of Civil Engineering ; 2014
    In:  Vestnik MGSU , No. 3 ( 2014-3), p. 82-91
    In: Vestnik MGSU, Moscow State University of Civil Engineering, , No. 3 ( 2014-3), p. 82-91
    Type of Medium: Online Resource
    ISSN: 1997-0935 , 2304-6600
    Uniform Title: Особенности работы соединений металлических элементов на заклепках различных типов
    URL: Issue
    Language: Unknown
    Publisher: Moscow State University of Civil Engineering
    Publication Date: 2014
    detail.hit.zdb_id: 2781261-3
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  • 3
    Online Resource
    Online Resource
    IOP Publishing ; 2018
    In:  IOP Conference Series: Materials Science and Engineering Vol. 456 ( 2018-12-31), p. 012095-
    In: IOP Conference Series: Materials Science and Engineering, IOP Publishing, Vol. 456 ( 2018-12-31), p. 012095-
    Type of Medium: Online Resource
    ISSN: 1757-899X
    Language: Unknown
    Publisher: IOP Publishing
    Publication Date: 2018
    detail.hit.zdb_id: 2506501-4
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  • 4
    Online Resource
    Online Resource
    EDP Sciences ; 2019
    In:  E3S Web of Conferences Vol. 97 ( 2019), p. 04033-
    In: E3S Web of Conferences, EDP Sciences, Vol. 97 ( 2019), p. 04033-
    Abstract: An important problem of modern engineering is to ensure the stability of buildings to a progressive collapse. One of the options for making calculations is to perform a static calculation with the use of the dynamic coefficient. The dynamic factors of damage of the structure depend on the failure time of the element, i.e. time during which the resistance of the damaged element is reduced to zero.To determine the time of exclusion, a series of experimental studies of stretched and compressed steel samples was carried out. The work of elements was studied after they had exhausted their carrying capacity (strength or stability). The results of a numerical study of a truss with damaged elements are presented. It is established that a significant part of the load is redistributed to the intact elements of the truss during deformations of the excluded element are smaller than the experimentally established deformations of the rods.
    Type of Medium: Online Resource
    ISSN: 2267-1242
    Language: English
    Publisher: EDP Sciences
    Publication Date: 2019
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  • 5
    Online Resource
    Online Resource
    EDP Sciences ; 2019
    In:  E3S Web of Conferences Vol. 97 ( 2019), p. 06022-
    In: E3S Web of Conferences, EDP Sciences, Vol. 97 ( 2019), p. 06022-
    Abstract: Reinforced concrete floors and steel beams are widely used in buildings and structures for various purposes. Reinforced concrete overlaps can be cast-in or precast of hollow-core slabs. The most effective floors in which the concrete slab is located in the compressed area of cross-section, in steel beams in the tension zone, and shifting forces, arising between concrete slab and the steel beam, are perceived by anchors. Precast slabs in comparison with cast-in ones have less labor-intensive performance, the beam spacing is equal to the span of reinforced concrete slabs, there are no intermediate beams in such overlaps, that allows to reduce the floor thickness. The inclusion of precast in steel-concrete cross-section requires joints with steel beams, which requires using of special anchors. Anchor perceives shear forces and ensures the joint operation of the plate and the steel beam. In addition, for beams with narrow flange, the anchor device can provide the required width of the support slabs. The calculation of the attachment points of the anchors to the steel beam is carried out using three variants of calculation methods, which allow to determine the forces acting on the anchor. For practical application, a wire-element model has been proposed and managed to get forces in a steel beam, slab and anchors the width of the slab recommended by the standards should be included in the calculation model.
    Type of Medium: Online Resource
    ISSN: 2267-1242
    Language: English
    Publisher: EDP Sciences
    Publication Date: 2019
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  • 6
    Online Resource
    Online Resource
    EDP Sciences ; 2021
    In:  E3S Web of Conferences Vol. 263 ( 2021), p. 01017-
    In: E3S Web of Conferences, EDP Sciences, Vol. 263 ( 2021), p. 01017-
    Abstract: Alkali-silicate thermal insulation materials (foam silicates) belong to the group of mineral heat insulators. Their main disadvantage is insufficient water resistance, to increase which special water-strengthening additives are introduced into materials. The aim of this work was to obtain and study foam silicates in granular (FGCG) and slab (FGCS) forms using a new production technology characterized by a simple one-stage technological scheme. Natural or technogenic amorphous silica, glassy sodium silicate (with the addition of carbonate or hydroxide) and a carbon-containing foaming agent, were used as the raw materials. Some part of the silica component was included in the binder solution, which made it possible to increase the silicate modulus in the final product to 5-10. This factor together with rather high Al 2 O 3 concentration in the silica raw, made it possible to obtain foamed materials of very high water resistance. Another feature of the applied technology was a high foaming temperature (750–900°C). This factor makes a significant contribution to improving the water resistance of foam silicates, and significantly reducing their thermal conductivity and water absorption. As a result, FGCG was obtained with a bulk density of 170-440 kg/m 3 (for FGCS – 300-400 kg/m 3 ), a compressive strength in a cylinder of 0.5-6.3 MPa, a thermal conductivity of 0.046-0.084 W/(m·K) and a water absorption of 7.8-13.5% by volume. Mass loss of the specimens in boiling water was 0.12-0.33%, which puts obtained foamed materials on a par with most waterproof foam silicates being produced today.
    Type of Medium: Online Resource
    ISSN: 2267-1242
    Language: English
    Publisher: EDP Sciences
    Publication Date: 2021
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  • 7
    Online Resource
    Online Resource
    EDP Sciences ; 2021
    In:  E3S Web of Conferences Vol. 263 ( 2021), p. 01018-
    In: E3S Web of Conferences, EDP Sciences, Vol. 263 ( 2021), p. 01018-
    Abstract: Methods of recycling polyethylene terephthalate waste are analyzed. Thermoplastic waste has great potential for mechanical recycling. Lack of information on the quality of recycled products and their applicability for specific purposes hinders their use. Shredding is a main process in mechanical recycling. Due to the viscoelastic properties, the cost of grinding polymer waste is several times higher than for most brittle mineral materials. Cutting and impact equipment is often used to shred plastic waste. To obtain micron-sized polymer particles, the technologies of cryogenic grinding and wet grinding in solvents are used, which is followed by high operating costs. The purpose of this work was to develop an economical method for producing fine powders from polyethylene terephthalate waste. The specific surface of the powders has been investigated. To investigate the destruction, differential thermal analysis and infrared spectroscopy were used. The technology of secondary mechanical recycling is proposed: crushing, melting of waste, natural or water cooling of the melt, grinding on equipment typical for brittle materials. A dispersed product with a proportion of micronized fraction of about 50% was obtained for use as filler in composites. The resulting product is more degraded in comparison with the feedstock. Therefore, its use as binders is advisable in applications where a decrease in initial properties is permissible, in products with a long lifecycle, for example, in the production of building materials. The use of waste thermoplastic in applications other than the original one does not always reduce the value of the technology.
    Type of Medium: Online Resource
    ISSN: 2267-1242
    Language: English
    Publisher: EDP Sciences
    Publication Date: 2021
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  • 8
    Online Resource
    Online Resource
    EDP Sciences ; 2021
    In:  E3S Web of Conferences Vol. 263 ( 2021), p. 01010-
    In: E3S Web of Conferences, EDP Sciences, Vol. 263 ( 2021), p. 01010-
    Abstract: Construction on problem soils or in permafrost conditions involves using of pile foundations with a ventilated space under the floor structure. In this case, additional thermal insulation is required under the first-floor structure (above the ventilated space). The aim of research was to develop insulation systems for buildings on pile foundations for different climatic zones, including conditions of the arctic region and other regions with a predominance of ever-frozen ground. With the help of the THERM computer program, the conditions of bidimensional heat interchange in the enclosing structures of a building with pile foundation were simulated. The resulting models were analysed in terms of the thermophysical characteristics of the structures. As a result, the optimal version of the insulation system was chosen, effective both in the climatic conditions of the midland and in the especially cold conditions of Yakutia and Trans-Polar region (The Subarctic). This system included insulation with mineral wool slabs along the facade walls, with extruded foamed polystyrene along the basement part and the floor structure, and with rolled foamed polyethylene (with the formation of a seamless insulation shell) along the ventilated space under the floor structure and above, on top of insulation boards.
    Type of Medium: Online Resource
    ISSN: 2267-1242
    Language: English
    Publisher: EDP Sciences
    Publication Date: 2021
    detail.hit.zdb_id: 2755680-3
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  • 9
    Online Resource
    Online Resource
    EDP Sciences ; 2021
    In:  E3S Web of Conferences Vol. 263 ( 2021), p. 05023-
    In: E3S Web of Conferences, EDP Sciences, Vol. 263 ( 2021), p. 05023-
    Abstract: A modern human receives most of the radioactive annual dose in buildings from radon and its progeny, which can cause lung cancer. In such conditions, the design of radon-safe buildings is an urgent task in the context of preserving the population collective health. The paper shows the inefficiency of using the radon flux density from the soil surface as a criterion for the potential radon hazard of a construction site due to its significant temporal and spatial variability. The design of an experimental device, which makes it possible to simulate the real conditions of radon transport in soil in laboratory conditions, is described, and the results of determining the dominant radon transport mechanism in soil by means of a laboratory experiment are presented. A method for determining the required radon resistance of the floor structure is proposed on the basis of the diffusion model of stationary transport.
    Type of Medium: Online Resource
    ISSN: 2267-1242
    Language: English
    Publisher: EDP Sciences
    Publication Date: 2021
    detail.hit.zdb_id: 2755680-3
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  • 10
    In: E3S Web of Conferences, EDP Sciences, Vol. 263 ( 2021), p. 05028-
    Abstract: Some topical issues of strategic planning of construction and reconstruction of heat supply systems are considered in the article, taking into account the features of its organization in the certain territories of our country with different climatic, economic, city-planning and social conditions. The article presents the results of the analysis of the strategic documents of the heat supply development in various countries, which showed the need of formation of management instruments, providing the possibility of planning of specific scenarios of the heat supply development in the territories of our country. The key conditions of strategic planning, are revealed. They include providing the solution of social and environmental problems as well as the matters of energy security of consumers, which are in the centre of global environmental challenges now. The legislative arrangements and the experience of the use of "Heat Supply Schemes" in the territories of the Russian Federation are chosen as the materials. The scenario approach with the use of the method of the hierarchy analysis is considered to be the basis for planning of construction and reconstruction of the facilities of the heat supply systems. According to the scientific approach, chosen in the research, the level hierarchy of the strategic planning process is offered. The major factors, influencing the development of heat supply of territories are analysed, the main factors and their purposes, as well as the basic scenarios of the development, are described. The authors offer four scenarios for the choice of options for construction and reconstruction of the facilities of heat supply systems, taking into account the practice of its organization in various countries. The importance of the basic scenarios for the strategic development of the heat supply system in the territory is estimated according to the hierarchy levels on the basis of the method of paired comparisons with the subsequent aggregation of the received results. The approbation of the offered management instrument on the example of the urban area allow to prove the scenario of the decentralized heat supply of the explored territory as the most perspective scheme as well as to raise the questions of possible expansion of the offered management instrument.
    Type of Medium: Online Resource
    ISSN: 2267-1242
    Language: English
    Publisher: EDP Sciences
    Publication Date: 2021
    detail.hit.zdb_id: 2755680-3
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