bluuebunny/crossref_metadata_2025 huggingface dataset:
Research of non-metallic inclusions of E90KhAF rail steel
Authors: Simachev A S , Oskolkova T N , Umansky A A
Published: August 2020

This article is devoted to the research of the non-metallic inclusions of the E90KhAF rail steel in different zones of continuous cast billets. It is established that in the rim zone the main non-metallic inclusions are silicates of iron and alumosilicates. Alumosilicates and silicates of iron are identified in the zone of columnar crystals. Sulfides of manganese (MnS), silicates of manganese, aluminum and iron are found in the central zone of the billet.
Patterns of changes in the plastic and deformation characteristics of rail steels alloyed with chromium in the temperature range of hot rolling
Authors: Umansky A A , Golovatenko A V , Simachev A S , Dorofeev V V
Published: August 2020

Based on the set of experimental studies for chromium rail steels of grades E76KhF, E76KhSF and E90KhAF, the basic laws governing the influence of hot rolling temperature on ductility and the regularities of temperature and strain rate influence in the temperature range of hot rolling on plastic deformation resistance are determined and scientifically substantiated. It was shown that for E76KhF steel at deformation temperatures of 1050 °C, a sharp decrease in ductility occurs due to the presence of cementite-type carbides (Fe, Mn, Cr)3C at the grain boundaries. For rail steels with a lower chromium content, the indicated ductility drop is not observed. It was established that an increase in the deformation temperature of rail steel E76KhSF causes a decrease in deformation resistance, and an increase in the strain rate significantly reduces this indicator. Also the fact that the deformation resistance decreases with distance from the surface to the central zone of continuously cast billets is established, which is due to an increase in grain size. Based on the obtained data, a new mode of rail rolling was developed in the conditions of the rail and beam workshop of EVRAZ ZSMK JSC, the introduction of which allowed the quality of the rails to be significantly improved as well as the technical and economic indicators of their production with an economic effect of approximately 120 million rubles/year.
Modeling and experimental study of the electrodes erosion of plasma torch EDP-104A in nitrogen plasma
Authors: Galevskiy G V , Rudneva V V , Orshanskaya E G , Galevskiy S G , Mishne I
Published: August 2020

Modeling and experimental studies of the electrodes erosion of plasma torch EDP-104A in nitrogen plasma were carried out. The resource of cathode and anode operation is determined by calculation. The conditions and performance of 178 cathodes were studied. The possibility of using natural gas to protect a tungsten cathode was investigated. The increase in the cathode life to the rated value was confirmed.
Development and application of a complex model of titanium diboride plasmosynthesis
Authors: Galevskiy G V , Rudneva V V , Orshanskaya E G , Efimova K A
Published: August 2020

An integrated multifactor mathematical model of plasmosynthesis of titanium diboride was developed. The model includes 3 submodels: “Plasma generation”, “Evaporation of raw materials”, “Boride formation”. The model provides the implementation of multivariate research and engineering calculations of plasma processing technological indicators of various types of titanium-containing raw materials, industrial products and waste. The convergence of the predicted and practical results for various types of raw materials is 10.4-12.9%. In all cases, lower values of practical data are noted in comparison with the calculated ones, which is due to the influence of non-isothermal heat carrier gas.
Prediction of carbon dioxide emissions from fuel combustion
Authors: Sterligov V V
Published: August 2020

An objective method for estimating carbon dioxide emissions using specific emissions per 1 kJ of fuel energy is presented. To unify the calculations of the calorific value of gaseous and solid fuels, it is proposed to use a regression calculation model for both coal and gas. The applicability of this approach is proved and on its basis the calculation of possible CO2 emissions at a given unit power.
Mathematical modeling of the process of carbon bubbles formation in the interaction of a gas jet and a melt bath in the oxygen converter
Authors: Solonenko V V , Protopopov E V , Sarychev V D , Granovskii A Yu , Temlyantsev M V
Published: August 2020

The article discusses the issues of modeling the processes of interaction of gas jets and metal melt during blowing of a converter bath. The authors developed and implemented using the finite element method a mathematical model based on a direct numerical solution of the Navier-Stokes equation without using a turbulence model. This model helped to study the dynamics of the velocity field and the boundary of the penetration of the jet into the metal. According to the results of mathematical modeling, a mechanism for the formation of carbon monoxide bubbles is suggested.
Thermocyclic deformation, annealing, and physical properties of low-carbon steel 10
Authors: Prudnikov A N , Prudnikov V A , Fastykovskii A R , Umansky A A
Published: August 2020

The results of the influence of thermocyclic forging and annealing in the range of 100 ÷ 900 °C on the microstructure, coercive force and linear expansion of steel 10. Hot cyclic forging was carried out on slabs 900×700×500 mm in size on the hydraulic press with a force of 20 MN under industrial conditions of ZSMK OJSC (Novokuznetsk). Subsequently, the billets were rolled on a 3 mm thick sheet at OAO NMZ (Novosibirsk). The use of preliminary thermocyclic deformation increases the coercive force by no more than 8%. The possibility of reducing the coercive force of sheet steel made using thermocyclic forging was shown to be almost 3 times lower than the initial untreated state due to subsequent annealing at 900 °C for 10 hours. In addition, this annealing mode reduces the average linear expansion temperature coefficient of sheet steel by 6% in the temperature range of the test 50-450 °C.
Use of waste sludges from chemical enterprises as secondary metallurgical raw materials
Authors: Krivosheev S V , Gordievskiy O I , Nozdrin I V , Garaev R G
Published: August 2020

The characteristics of dump zinc-containing sludges from chemical enterprises producing artificial fibers are given. The analysis of quantitative, chemical and phase compositions of sludge fields is carried out. The possibility of pyro- and gyrometallurgical processing of these materials was established. The need for preliminary preparation of sludge for processing is shown. Technological recommendations for obtaining marketable sulfate and zinc oxide are formulated.
Mathematical modeling of radiant heat transfer in the melting furnace working space
Authors: Shvydkii V S , Lavrov V V , Devyatykh E A
Published: August 2020

The paper provides mathematical modelling results of radiation flow formation in the work space of the smelting (glassmaking, open-hearth) furnace with different heating patterns and flow distribution over the surface of the bath and enclosing structures. A significant influence of the flame length upon technical and economic parameters of furnace operation was found out.
Resource and energy saving technology for producing high-quality steel castings with heat-time treatment
Authors: Lubyanoy D A , Mamedov R O , Knyazev S V , Sokolov B M , Oznobikhina N V
Published: August 2020

Today, the current direction in the development of steel production is resource and energy saving. So, one of the problematic issues in the steelmaking process is to reduce the consumption of ferroalloys. The possibility of improving the quality of castings, due to the heat-time treatment of the melt is considered. The melt is overheated to high temperatures by holding in the furnace. Because of that, the yield of suitable products increases, the metal consumption of products decreases.
Hardness of low-alloy steel obtained by cold metal transfer in the magnetic field
Authors: Shlyarov V , Zagulyaev D , Chen X , Gromov V
Published: August 2020

In recent years, the technology of creating metal materials by the Cold Metal Transfer method has been actively developed, which helps to obtain products of various shapes and sizes. The hardness of 9CrMoV-N low-alloy steel obtained by the Cold Metal Transfer method in the field of a permanent magnet was investigated. The magnetic field induction did not change in the entire series of tests and was equal to 200 mT. As a result of the studies, it was found that the hardness of the obtained sample is more than 2 times higher than the hardness of the starting material and is 590.97±14.87 HV in comparison with the hardness of the wire before surfacing 265 HV. It was found that the distribution of hardness over the volume of the material is heterogeneous and depends on the place of testing. It was suggested that changes in hardness are associated with the structural features of the deposited material.
Development of ecotourism infrastructure at protected areas of Primorsky Krai
Authors: Maslovskaia Oksana , Kopeva Alla , Petrova Ekaterina , Ivanova Olga , Khrapko Olga
Published: August 2020

The paper discusses the features of the formation of ecotourism infrastructure in specially protected natural areas (PAs) of the Primorsky Krai. The need for the research is due to the lack of basic strategies for the development of Primorsky Krai protected areas, the lack of developed route programs for various categories of visitors and weak infrastructure of ecological routes at protected territories of the Primorsky Krai. Research method: a comparative analysis of the landscape structure of protected areas in the Primorsky Krai and the world. As a result of the study, the location and boundaries of nature reserves, recreational territories, economic zones in each of the functional zoning schemes of the two protected territories “Leopard Land” and “Call of the Tiger” were identified and depicted. Nodal points of the considered landscapes located in tourist centers and nearby villages are highlighted. As a result of the study, it was concluded that the infrastructure for nature tourism should be a subject to the principles of sustainable development of territories, minimize the negative impact on nature and increase the safety and comfort of tourists.
Perspectives for using a three-beam space-planning structure in creating residential grid structure development
Authors: Nureev Tagir , Popov Anton
Published: August 2020

Problem statement. The aim of the study is to reveal new urban planning possibilities in applying the three-beam architectural and planning structure under the changed sanitary regulations and standards (SanPiN 2017) in the central and southern zones of insolation in the Russian Federation.

Results. The main results of the study consist in the development of proposals for the central and southern zones of insolation in the Russian Federation, which allow achieving the maximum normative indicators of the building area density.

Conclusion. The significance of the results obtained for architecture is the geographical boundaries defined by the authors for the use of residential three-beam space-planning structure in modern conditions of housing development. The research is based on the analysis of urban planning indicators, including renovation of existing building area, and the typology on the basis of the rotation angles of the three sectors in different azimuth directions.
Features of modern methods of forming embankments
Authors: Kuleeva Lalya , Burova Tatyana , Listovskaya Ludmila , Ibragimova Ainaz , Saifullina Ilseyar
Published: August 2020

This article analyzes the functional urban development of embankments, identifies features used in the creation of recreational forms along, and offers suggestions as to functional planning organization.

Results. The main result of the study is to identify the primary methods of organizing embankments. Modern practice, characterized by the use of new technologies and materials, attracts people with their aesthetics and unique possibilities for spending time on the embankments.

Findings. Significant results were obtained for the design process in determining characteristics of organization along the embankment zone and integration into the urban environment. A variety of opportunities for the organization of the environment were being considered to create a comfortable atmosphere. Such factors as transport accessibility and safety of pedestrians, functional location of objects, proper arrangement of lighting and landing systems, creation of a unified environment throughout the area while maintaining natural and ecological balance are taken into account.
Creation of an architectural space in oncological rehabilitation centers
Authors: Gaiduk Albina
Published: August 2020

In the modern world, individual space features in architectural design are becoming a priority. A crucial task is the creation of clinical rehabilitation centers (CRCR), capable of providing high value care to oncological diseased (OD) children in remission [1]. According to the Ministry of Health of the Russian Federation for the last period, the disease incidence of children and adolescents with oncology diseases is 15 cases per 100,000 children. Over the past decade, the number of OD children, registered annually, has increased by 12 %. According to the State Statistics Committee data, published in 2019 in the Russian Federation, about 4,000 new cases of malignant neoplasms in children are registered. The study found the emergence of qualitatively new structural units in medical institutions, the activities of which are aimed at the partial rehabilitation of oncological diseased children [2, 3]. The absence of a complex approach in the rehabilitation of oncological diseased children is also noted.
Structural transformation of small cities
Authors: Arsenteva Yulia , Zaletova Elena , Ismagilova Svetlana
Published: August 2020

One of the key problems in urban planning is the present-day development of small cities experiencing negative consequences of new socio-economic reality. The need for searching the ways to raise the investment attractiveness of small cities becomes obvious as also the need to revise the goals of their planning structure development. On the example of Chistopol city possible ways of structural transformation, aimed at both preservation of small city natural attractiveness and opening up new opportunities for its urban development, are considered. One of the crucial goals of the research is to reveal the effective methods of small cities’ central part spatial transformation directed on satisfying new social needs of residents while maintaining the valuable historical heritage. As a result of comprehensive assessment of the current state of city’s central part spatial organization, its characteristic features are revealed and new city center formation model is proposed, which structural and functional organization is more complex and emphasizing the idea of creating high quality urban environment.
Principles of organizing new residential development in the peripheral areas of the single-industry towns of the middle Volga
Authors: Shaimardanova Camilla , Prokofiev Evgeny
Published: August 2020

The article discusses current problems and trends in the residential development in the peripheral territories of single-industry towns in Russia. Based on international research, a comparative analysis of the periphery state of cities in Europe, the United States and Asia is presented. An architectural and urban planning analysis of the territories of five single-industry towns in the middle Volga region of the Russian Federation was carried out in order to identify territories suitable for the organization of a residential environment. Based on the research carried out, the principles of organizing the spatial environment of the peripheral zones of single-industry towns in Russia are defined and formulated. The proposed methods of forming architectural and urban planning space can form the basis of urban planning activities at the stage of development of master plans, as well as become the basis for the formation of a new comfortable living environment.
Architecture of innovative educational spaces of a university campus. On the example of SYSTEMS Centre of Engineering Systems in Construction at KSUAE (Kazan, Russia)
Authors: Akhtiamov Ilnar , Akhtiamova Rezeda
Published: August 2020

University campuses in Russia require updating educational methods, modernizing buildings and territories, improving the material and technical base. Transformations should take place in accordance with the latest trends in the design of educational spaces. The article proposes an integrated approach in the design of innovative educational spaces, guided by the basic principles: openness and connectedness; multifunctionality and transformability; harmony. This method was used in the design and implementation of the modernization project of the Center for Engineering Systems in the construction of Kazan State University of Architecture and Engineering. The successful launch and operation of the center confirms the relevance of the method used.
Testing the methods of reconstruction of the spatial solution of the pedestrian street
Authors: Grishina Maria
Published: August 2020

This article describes techniques for designing a pedestrian city street in an existing building. At the beginning of this article, methods are described that determine the level of elaboration of the modernization of a city street into a pedestrian. Also publications on research into the problems of modern urban spaces are mentioned. Then the results of the analysis and the concept of the design solution are presented in the article. At the end, the assessment of the developed design solution is given. In conclusion, the results of adapting existing methods for designing urban improvement for modern engineering technologies are presented. As a result of the development of a design solution, wastelands were excluded from urban space and the promising urban development value of the territory as a whole was increased.
Analysis of the efficiency of obtaining reliable data when operating with number sets in simulation of bridges structural components
Authors: Maystrenko Igor , Zinnurov Tagir , Erohin Dmitriy , Maystrenko Tatiana
Published: August 2020

The issue of reducing the complexity of a multifactorial simulation experiment to an acceptable level is relevant. The simulation complexity is characterized by the computing capabilities of a PC while maintaining a given level of accuracy and certainty of the problem being solved. Many authors neglect the justification of the sample size, thereby reducing the experiment’s reliability. Loads are stochastic, therefore, in the calculations, they are determined by rated and design values. However, the Monte Carlo methods allow the specific realization of loads based on the distribution law chosen. Techniques for optimizing the multifactorial simulation experiment procedures have been proposed on a test example of adding permanent loads due to the bridge pavement layers. They allow excluding the procedure of building multidimensional laws of the final distribution of random parameters, while sequentially transforming them from input to output values. The minimum required simulation experiment size, which should exceed 7.5 106 realizations and is determined by the product of the number of tests N by the number of runs n, has been experimentally justified for the structural components of bridges.
Structures of steel-reinforced concrete beams of bench manufacture for bridge spans
Authors: Eremeev Valery , Shmelev Gennady , Eremeev Pavel , Eremeev Daniil
Published: August 2020

The issue of optimizing the span structure of road bridges is considered. The proposed method is excluding reinforced concrete from stretched zones and replacing it with steel. The combined work of reinforced concrete in a compressed zone and steel in a stretched zone makes it possible to achieve the most rational solution in terms of material consumption, but leads to additional costs. The article describes the history and experience of using steel-reinforced concrete beams with the span length varying from 12 to 33 m. The advantages of the proposed structure over the typical design of non-diaphragm beam spans are confirmed. Comparison of typical and proposed cross sections of span structures is given. Advanced design of steel-reinforced concrete beams was developed, excluding monolithic seam on concrete slab, which simplifies installation and reduces the complexity of spans. Design solutions are verified by patents of the Russian Federation. Photos of steel-reinforced concrete beams and bridge structures are provided-both built and under construction.
Energy method for calculating insolation of residential apartments
Authors: Kupriyanov Valery , Sedova Farida
Published: August 2020

The analysis of the current codes for the insolation in apartments has been done by the authors. It is shown that the insolation assessment during exposure is not sufficiently correct. The current codes do not take into account the amount of solar energy, the transmittance of UV radiation with double-glazed windows, the dimensions of light openings and the room parameters. The current codes for insolation do not contain requirements for the essential level of sanitation.

The proposed energy method of calculating insolation corrects the shortcomings of the existing Sanitary Codes method considering the climatic and structural factors. It introduces an unambiguous quantitative measure of insolation-the dose of UV radiation as well, which provides a given level of bactericidal efficiency of room sanitation.

Additionally a proposal to specify the bactericidal efficacy level of irradiation based on the most common microorganisms in living rooms (Staphylococcus aureus and Escherichia coli) has been made.

An example of the UV radiation dose calculation in rooms is given, which provides a necessary level of bactericidal efficiency.
New nodal connection of thin-walled cold formed profiles with a trapezoidal wall using separate welded bushings
Authors: Kuznetsov Ivan , Gainetdinov Rishat
Published: August 2020

The article suggests a new constructive solution of the node made of thin-walled cold-formed profiles with a part of concave flat wall with the use of separate welded bushings for bolt arrangement. To assess the load-carrying capacity of the proposed node numerical and experimental study of a prototype model, consisting of thin-walled cold-formed profiles connected by a gusset plate with a bolt, using separate welded bushings was fulfilled. By results of researches character of pressure distribution in places of bolts installation is revealed and actual carrying capacity of new node is defined. The significance of the obtained research results for the construction industry lies in the fact that the new design solution of the node with the use of separate welded bushings makes it possible to eliminate the gap between the gusset plate and trapezoidal wall of the profile, thus performing the bolt fastening in this place and improving the actual work of the node. It should be noted that the proposed solution of connection with the use of separate welded bushings allows increasing the carrying capacity of the node, taking into account the installation of bolts in the concave part of the profile wall.
Dynamic stability of viscoelastic orthotropic shells with concentrated mass
Authors: Khodzhaev Dadakhan , Vatin Nikolay , Abdikarimov Rustamkhan , Normuminov Bakhodir , Mirzaev Bakhadir
Published: August 2020

Viscoelastic thin-walled structures such as plates, panels and shells, with mounted objects in the form of additional masses are widely used in modern technology. The role of such additional masses is often played by longitudinal and transverse ribs, tie-plates and fixtures. When designing such structures, it is relevant to study their dynamic behavior depending on the mass distribution, viscoelastic and inhomogeneous properties of the material, etc. In this paper, the dynamic stability of a viscoelastic shell carrying concentrated masses is considered, taking into account the nonlinear and inhomogeneous properties of the material. A mathematical model of the problem is described by a system of integro-differential equations in partial derivatives. With the Bubnov-Galerkin method, the problem is reduced to solving a system of ordinary nonlinear integro-differential equations. To solve the resulting system with the Koltunov-Rzhanitsyn singular kernel, a numerical method based on the use of quadrature formulas is applied. The effect of the viscoelastic and inhomogeneous properties of the shell material, location, and the amount of concentrated masses on stability is studied.
On the stress state of thin-walled isotropic building constructions of the shell type
Authors: Timergaliev Samat , Uglov Aleksandr
Published: August 2020

The stress-strain state of elastic inhomogeneous isotropic shallow thin-walled shell constructions is studied in the framework of S.P. Timoshenko shear model. The stress-strain state of shell constructions is described by a system of the five equilibrium equations and by the five static boundary conditions with respect to generalized displacements. Equilibrium equations are second-order partial differential equations that are linear with respect to tangential displacements, rotation angles, and non-linear with respect to normal displacement (deflection). The aim of the work is to find generalized displacements from a system of equilibrium equations that satisfy given static boundary conditions. The research is based on integral representations for generalized displacements containing arbitrary holomorphic functions. Holomorphic functions are found so that the generalized displacements should satisfy five static boundary conditions. The integral representations constructed in this way allow to obtain a nonlinear operator equation with respect to the deflection. The solvability of the nonlinear equation with respect to deflection is established with the use of contraction mappings principle.
An investigation of the influence of the reduced elasticity modulus on strength of pultruded frp members in bending
Authors: Kuznetsov Ivan , Salakhutdinov Marat , Shakirzyanov Farid , Khaydarovand Lenar , Aripov Daler
Published: August 2020

The polymer composite known as Fibre Reinforced Polymer (FRP) has several advantages over conventional materials. It has been slowly incorporated into civil infrastructures, because the general regulations have not yet been officially introduced. Pultruded FRP manufactures have internal standards of organizations and Guidelines. Therefore, the design identifies issues that require clarification. This study presents influence of the reduced elasticity modulus on strength of pultruded FRP members in bending with a symmetrical cross-section. The position of the neutral line and calculation of strength and deflections with and without reduced modulus of elasticity are determined in the study. Comparison of the results of calculations showed that when taking into account the reduced modulus of elasticity, the deformability is reduced by up to 15 %. The significance of the results obtained for the construction industry consists in the possibility of a refined calculation of the flexural pultruded FRP members taking into account the reduced modulus of elasticity in order to effectively use the strength reserves and reducing material consumption.
Wind impact on low-rise buildings when placing high-rises into the existing development
Authors: Mironova Juliya
Published: August 2020

As height of new development rises, there is an increase in pressure from the windward side and in eddy flows from the leeward side of a high-rise building. This pressure affects not only neighboring high-rises, but also it has an impact on low-rise existing ones. The purpose of the study is to model wind flows to determine maximum aerodynamic wind effects on multi-storey buildings and their surroundings. It also aims at improving the expression for defining maximum wind load depending on the building height and the distance to it. In this study numerical experiments on modeling the distribution of wind flows in a virtual wind tunnel for an existing low-rise building have been carried out. Based on their results, an increasing coefficient in the expression for determining the wind load depending on the height of a multi-storey building and the distance to it is proposed. The results obtained can be used in determining wind loads during the reconstruction of low-rise buildings and their verification calculations when placing multi-storey and high-rise buildings in existing buildings.
Efforts redistribution in statically indeterminate bar systems based on scaffolding by force limiter
Authors: Lenar Khaidarov , Gennady Shmelev , Marat Salakhutdinov
Published: August 2020

Scaffolding structures are commonly statically indeterminate and therefore the load-bearing capacity of the elements is not fully used, and the load-bearing capacity of the structure is limited by the most loaded element. It is important to redistribute the forces in the structure elements to make the most efficient use of their load-bearing capacity. It is suggested to introduce force limiters into the most loaded elements that allow shifts inside the element when the force limit value is reached. Due to this displacement the forces inside the element are reduced and redistributed to the adjacent elements. A numerical analysis has been carried out on the example of wall construction to assess the impact of the force limiter on the load-bearing capacity of the structure. The article presents the design of a force limiter designed for vertical diagonal. Laboratory test of the force limiter as part of scaffolding assembly was carried out.
Stress-strain state of the connection node of translucent structures with the load-bearing frame of the facade system
Authors: Antonov Anatoliy , Shmelev Gennady , Khaidarov Lenar
Published: August 2020

The article presents the results of studying the stress-strain state of the elements of the connection node of translucent modules with a load-bearing frame as part of a standard post-and-crossbar facade system. The research is aimed at studying the initial stresses and deformations of the system node elements in its design position without applying external loads. At the initial stage, experimental studies were conducted to determine the elastic modulus of rubber inserts, which are the main elements that transmit forces from translucent modules to the supporting frame of the system. Based on the results of the tests, an approximated graph of the dependence of stresses on deformations of rubber inserts was obtained, which was exported to the software package, for modeling their actual work when calculating by finite element methods. At the stage of numerical studies geometrically and physically nonlinear problems of contact interaction of elements were solved, the resulting picture of the stress-strain state of the node in position before the application of loads and impacts was created, the value of compression of the external pressure profile to the load-bearing frame was set.
Subgrade vertical deformations of a building in the zone of a deep pit influence
Authors: Mirsayapov Ilizar T , Aysin Niyaz N
Published: August 2020

The existing methods for calculating the settlements of the foundations of buildings are developed for the soil mass without defects and damage. It is also assumed that the physical and mechanical characteristics of the soil are constant throughout the life cycle of buildings and structures. But the mechanical characteristics of subgrade soils are unstable and continuously change under the influence of various factors. The use of existing methods of calculation leads to inadequate settlement estimates of the subgrade and foundations of buildings and structures. In this regard, this work has developed a method for calculating the settlements of bases and foundations of buildings, taking into account the formation and development of defects and damages in the soil structure in the zone of influence of a deep pit. This method allows you to take into account the influence of factors such as dilation, formation and development of cracks, hardening, changes in the friction angle, shear modulus and deformation modulus. The developed method was tested on a real reconstructed object. Geotechnical monitoring for one year confirmed the results of calculations using the proposed methodology.
Modified trilinear stress-strain diagram of concrete designed for calculation of beams with fiberglass rebar
Authors: Mirsayapov Ilshat , Apkhadze George
Published: August 2020

An improved technique for determining the strength of reinforced beams with polymer composite reinforcement based on a nonlinear deformation model using a three-line diagram of concrete deformation under uniaxial compression with an elastic, elastic-plastic zone and a concrete softening zone is considered and proposed. The features of the strength analysis of beams with fiberglass reinforcement are revealed. The calculation method presented in this article allows us to minimize the use of empirical coefficients to determine the height of the compressed zone of concrete and at the same time does not lead to labor-intensive calculated dependencies. The method is based on the use of the Euler – Bernoulli beam theory and the use of physical stress-strain relations for concrete. This calculation method allows you to set accurately the height of the compressed zone of concrete, and accordingly the strength of the beam elements in the normal section. Good results of comparison with experimental data were obtained.
Cement stone, modified by galvanic sludge
Authors: Stepanov Sergei , Krasinikova Natalya , Makarov Dmitry
Published: August 2020

The relevance of the research topic stems from the use of multi-tonnage industrial waste in cement systems. One such waste is the sludge resulted from electroplating aluminum alloy products. Galvanic (electroplating) sludge is pasty and unstable in moisture. For this purpose, it was previously dried and then grinded so it could be rationally used. Impact of sludge on technological properties of cement stone and strength properties of cement stone were studied according to standard normative methods. It is shown that galvanic sludge increases the water demand of cement paste. Therefore, the joint effect of naphthalene formaldehyde and polyester carboxylate-based sludges with plasticizing added was studied. Their efficiency depends on the way they are produced. The mixed use of galvanic sludge with plasticizing additives reduces the water-cement ratio by 20-40 %, increases the strength of cement stone within the early hardening time by 3 times and in 2 times in the grade age. The phase composition of the modified cement stone was studied using defective thermal analysis. It was established that using galvanic sludge together with plasticizing additives decreases portlandite.

The article can be useful for those recycling the waste in question.
Composite gypsum binder under introducing thermally activated clay as a pozzolanic component and adding ground limestone
Authors: Khaliullin Marat , Dimieva Alsu
Published: August 2020

The purpose of this article is to study the effect of ground limestone additives on the basic physical and mechanical properties of the composite gypsum binder. It includes portland cement and pozzolanic additive of thermally activated clay as hydraulic components to reduce the consumption of more expensive calcining components of the binder. Using standard methods of research building materials we have obtained dependencies that characterize the effect of adding ground limestone on the water demand of the composite gypsum binder, its density, strength, water absorption, and water resistance of artificial stone based on it. It was established that the introduction of limestone into the composite gypsum binder composition with specific surfaces 500-800 m2/kg in an amount of up to 5-10 % by weight causes an increase in compressive strength by 15 % compared to control samples. When introducing up to 10-15 % by weight of limestone with a dispersion of 300 and 500-800 m2/kg, respectively, the strength remains at the level of additive-free samples with the preservation of the softening coefficient corresponding to water-resistant binders.
Heavyweight Concrete Based on Hydromechanochemically Activated Binder
Authors: Pimenov Sergey
Published: August 2020

The results of the influence hydromechanochemical activation of the cement with superplasticizing admixtures, both individually and jointly, on the structure formation of cement stone, the physical and technical properties of heavyweight concrete. An analysis of the microstructure and chemical elements in the spectrum of the surface of a cement stone prepared with preliminary hydromechanochemical activation of the binder with superplasticizing admixtures is presented. The method of hydromechanochemical activation of cement with a superplasticizing admixtures can be recommended for the production of quick-hardening concrete and mortars. The production of quick-hardening concrete is especially important: monolithic concreting in winter, when it is necessary to gain critical strength in concrete in a short time; precast concrete production at precast concrete plants, where it is possible to reduce energy costs for steaming products; modern additive printing technologies using a 3D building printer, requiring the development of new effective quick-hardening mortars and concrete.
Cement stone, modified by chemical water treatment sludge
Authors: Krasinikova Natalya , Stepanov Sergei , Makarov Dmitry
Published: August 2020

Chemical treatment of municipal and industrial wastewater is becoming increasingly common in the world, resulting in sludge formation. But only a small fraction of the waste is disposed of. Therefore, the issue of the potential use of these wastes in making construction materials is vital.

This paper examines the possible use of multi-tonnage industrial waste, in particular, sludge of chemical water treatment (SHVO) produced by combined heat and power plants in cement systems. Sludge of chemical water treatment is a pasty mass unstable in moisture. For this purpose it is advisable to pre-dry this waste until it becomes a fixed-mass, and then grind it. The impact of SHVO on the technological properties of cement paste and strength properties of cement stone was studied. The article shows that the introduction of SHVO into cement paste increases its water demand. The joint effect of naphthalene formaldehyde and polyester carboxylate-based sludge with additives was studied. Their efficiency depends on the way they are produced. The use of sludge with superplasticizers reduces binding agent consumption by 7.5% without loss of strength properties and reduces porosity of cement stone.

It was established that the introduction of SHVO into cement systems changes the physiography of newgrowths.
Guaranteed management of the prevention, detection, and proof of offenses in socio-technical construction using a geoinformation system
Authors: Mironov Aleksey , Mironova Anna , Burlov Vyacheslav
Published: August 2020

In the conditions of narrow departmental management, the administrative practice integrity in socio-technical construction is being destroyed by a lack of completeness and authenticity of administrative offense proceedings within a reasonable time. The timely application of the geoinformation system in order to prompt prevention, reliable revealing and proper proving of offenses ensures a preventively guaranteed efficiency and security of socio-technical construction. This paper proposed a synthesis of the administrative practice management model in construction, based on the natural-scientific approach to the adoption of managerial decisions. The condition for the existence of guaranteed management, which relates the characteristics of processes and performance indicators, is concretized by the Kolmogorov-Chapman equations system. Network models of interacting processes of the revealing and proving of offenses, the origin and identification of violations, their neutralization through the managerial impact on the limited resources of administrative practice in construction and of geoinformation system are built. Based on the simulation results, the requirements for the geoinformation system that ensure guaranteed management and maximum security to the socio-technical construction within a reasonable time are determined.
Classification of construction work types considered with worn of main production assets
Authors: Ludmila Kokliugina , Alexei Kokliugin , Ruslan Ibragimov
Published: August 2020

The main results of the research consist in comparing the terms of construction work during the period of reconstruction or major overhaul in various normative documents and generalization to single result. Methods are proposed for resolving contentious issues, avoiding unnecessary costs and appealing to arbitration courts.

It is established that in recent years, the methods of organization and construction management have undergone significant changes.

It was revealed that normative documents of various institutions allow different interpretations of terms and concepts, which lead to controversial situations related to the classification of these works by tax authorities. The given problems arise at the stage of completion of construction work, when the adjustment in the design and contract documentation is practically impossible to execute.

An example of construction and installation works implementation during the overhaul of an industrial building is considered and analyzed. Discrepancies in terms are revealed in terms of performance of construction work during the reconstruction or overhaul period.
Cold water concreting technology using thermoactive formwork
Authors: Imaykin Dmitriy , Ibragimov Ruslan
Published: August 2020

The paper presents the study results of temperature and strength indices of structures while performing isothermal warming in thermoactive formwork. The effectiveness analysis of thermoactive formwork panels warming in the freezer with complex additive was also carried out. Thermoactive formwork is a box-shaped structure consisting of 20 mm thick panels of laminated plywood with built-in wires. The total size of the thermoactive formwork for concrete construction was 200×200×200 mm. Concrete mixture was laid in thermoactive formwork in layers and caked by rodding. Then concrete mixture was warmed up using heating wires. Samples were placed in the freezer at a temperature of 18 °C for 1, 3, 7, 28 days. However, the samples were kept in a positive temperature of about 16 °C during the first ten hours while the concrete mixture was stored in the freezer.

According to the experiment results it was established that the lowest temperature was in the center of a formwork, which proved that this formwork could be used at an ambient negative temperature. It was revealed that heavy weight concrete with complex additive had a compressive strength higher by 57 compared to the control sample.
Modeling the process of biodeterioration of cement compositions
Authors: Shakirzyanov Farid , Shakirzyanov Rashit , Kayumov Rashit , Stroganov Viktor , Sagadeev Evgeny
Published: August 2020

The paper studies the problem of developing the theoretical foundations of the processes of diffusion biodegradation of mineral building materials (cement composites) under the action of aggressive microorganism vital products. The impact of the aggressive environment of microorganisms on the material is taken into account on the basis of Fick’s 2nd law. The resulting equation is solved by the finite difference method. Some experimental and theoretical studies of influence of the aggressive environment of microorganisms on the strength characteristics of the samples of cement composites have been carried out. The mathematical regularities of influence of the exposure time to the aggressive environment of microorganisms and the diffusion coefficient on the strength characteristics of composites have been established.
Construction technology of fixed formwork and quality control
Authors: Evstigneeva Yuliya , Ibragimov Ruslan
Published: August 2020

The main results of the research are to find numerical solutions for selecting effective fixed formwork material for columns and analysis of technological operations. The use of fixed formwork of glass-magnesite sheet allows improving quality and stability of the structure, increase fire resistance, which helps to extend the life of the concrete structure.

Based on numerical and experimental studies, a model of the formwork fastener for a round column of 3 m high, with a diameter 500 mm was developed. A calculation model was created and the design of the formwork made of glass-magnesite sheet was calculated. So, for the diameter of the concrete column from 300 to 600 mm, the thickness of the glass-magnesite sheet varies in the range: 7-23 mm.

A workflow has been developed for the installation of fixed formwork and for concreting columns with the determination of the required amount and type of work, with the determination of the complexity; a workflow for the quality control of work has also been developed. Such periods as: accepting of elements of fixed formwork, installation of fixed formwork elements, accepting of timbering construction operations must be monitored.
Reprofiling of objects with monolithic reinforced concrete frame
Authors: Topchiy Dmitriy , Bolotova Alina , Vorobev Aleksey , Atamanenko Alevtina
Published: August 2020

The actual issues of improving the quality of the organization of production processes in the monolithic construction. The efficiency of the construction production is significantly affected by organizational and technological reliability. The main factors affecting the rate of organizational and technological reliability of monolithic construction. This index takes into account the statistical characteristics of efficiency and organizational risks that arise in the process of functioning of objects of monolithic construction. Revealed and substantiated the necessity of development of recommendations and methods that will allow assessment of the overall organizational and technological reliability of monolithic construction and make a rational decision on the adequacy of the selected preventive measures with correction of the calendar plan of construction in terms of technical risk. Study and analysis of functional efficiency of monolithic construction operations suggest that faulty organization of production processes creates the risk of noncompletion of a construction stage as scheduled, deterioration of the quality of works, and, consequently, a reduced structural reliability of the monolithic construction project.
Technology for reinforcing strip foundations of reconstructed brick buildings based on computer modeling
Authors: Galiev Ilyas , Ibragimov Ruslan , Ashrapov Azat , Radaykin Oleg
Published: August 2020

When resolving the issue of the foundations strengthening and reconstructed buildings foundations, it is necessary to consider the ground part of the building or structure as a whole. The foundations are the soil foundation under them. It is necessary to solve simultaneously the problem of reducing the sensitivity of a building or structure to uniform precipitation of foundations and to restore the spatial rigidity of the building.

In order to study this issue, a numerical experiment was developed-modeling and calculation of the reconstructed brick building bearing capacity based on varying the thickness of the brick wall.

The analysis of stress-deformed state portion of the structure revealed that the greatest deformation of the elements is obtained in the overlapping area bearing elements and the edge beam in the location area. The relative displacements study of the finite elements nodes showed convergence with field observations of the foundation beam deformation at the object.