bluuebunny/crossref_metadata_2025 huggingface dataset:
Mirror symmetry in transverse oscillations of ropes and shafts in electromechanical systems
Authors: Borshchinsky M Yu
Published: August 2020

The article explores the possibility of developing a mathematical description of the bending of a round beam, based on end supports, to construct a theory of oscillations of a curved shaft of a mine hoist. The results of the study allow to develop a model of transverse oscillations of the elastic shaft and a long rope in order to synthesize a microcontroller control system.
Generalization of experience and classification of risks of IT services by the stages of the life cycle
Authors: Kiseleva T V , Maslova E V
Published: August 2020

The article discusses several classifications of risks for various reasons. In addition, a classification of information risks by stages of the life cycle of an IT service is proposed.
Analysis of the status and development prospects of Siberian metallurgical cluster in Russia
Authors: Protopopov E V , Temlyantsev M V , Galevsky G V , Kozyrev N A , Korotkov S G , Fastykovskii A R
Published: August 2020

The characteristics of metallurgical production and metal products of Kuzbass enterprises, their heat and energy supply, environmental safety, training of specialist for their needs, directions of their innovative development are considered. It was confirmed that the metallurgy of Kuzbass forms the basis of Siberian metallurgical cluster in Russia and includes 7 enterprises, of which ZSMK is the undisputed leader. Metallurgy takes the 2nd place with the volume of 26.6% in the structure of the industrial sector of Kuzbass.
New technology of rails welding
Authors: Kozyrev N A , Shevchenko R A , Protopopov E V , Krat’ko S N , Khomicheva V E
Published: August 2020

Today, in the manufacture of long-length rail strings, the obligatory heat treatment is provided after the flash butt welding operation. The basis for this operation is the unsatisfactory mechanical properties of the rail joints immediately after welding. Welding heat cycles at pulsed reflow do not always allow a welded joint with a sufficient level of ductility to be obtained. In this case, the induction heat treatment used at rail welding enterprises in Russia increases the length of the heat-affected zone, which adversely affects the wear resistance of the rails during operation. This paper presents studies in industrial conditions that were previously conducted in laboratory conditions. Studies show the possibility of obtaining the necessary mechanical properties by controlling welding heat cycles without the use of induction heat treatment.
Technology for the reduction of iron oxides in the processing of metal slag scrap in the oxygen converter
Authors: Amelin A V , Protopopov E V , Kuznetsov S N , Kalinogorskiy A N
Published: August 2020

The characteristic features of slag formation and oxidative metal refining in 160-tonne converters of EVRAZ ZSMK JSC using metal slag scrap in the solid metal charge are considered. Technological advantages of the process are established for the reduction of iron oxides from the slag component of the iron-containing product in the processing of waste slags.
Small-scale production of cast porous and composite materials
Authors: Knyazev S V , Usoltsev A A , Kutsenko A I , Kutsenko A A , Sokolov S B
Published: August 2020

Modern foundry production should be equipped with advanced technologies, equipment and materials, have a significant reserve for its development in the future, which is unthinkable without a transition to digital production, which includes integrated automation of technological processes, digital control of technology parameters, materials and quality indicators of the finished products by the non-destructive control methods, as well as the use of new foundry materials obtained with the help of nanotechnologies.
Hardening of VK10KS hard alloy surface for solving tribological problems in machine-building
Authors: Oskolkova T N , Simachev A S , Glezer A M , Fastykovskii A R
Published: August 2020

Hard alloy with a gradient structure consisting of a viscous core made of VK10KS alloy and a more wear-resistant surface made of VK6-OM alloy is obtained by electrodischarge hardening alloying. In this case, the base of the alloy is able to absorb shock loads, and the surface can play the role of wear-resistant cutting elements.
Study of the characteristics of iron-containing waste from steelmaking and rolling production
Authors: Anikin A E , Galevskiy G V , Rudneva V V , Nozdrin E V
Published: August 2020

A study of the physicochemical characteristics of mill scale and dehydrated sludge from gas purification of oxygen-converter production was made. Their chemical, phase, particle size distribution and density are determined. It was established that the total iron content in the scale is 73.3%, in the sludge – 41.2%. The technological expediency of their use in metallization processes is determined. In this case, preliminary briquetting in a mixture with a carbon reducing agent is necessary.
Energy generation from wood waste
Authors: Solovyov A K , Koshkina G K
Published: August 2020

The reconstruction of the heating system of the administrative and amenity building of “Tekhnologii Retsiklinga” LLC is proposed by replacing the heat energy of electric boiler with the heat energy produced by a wood waste boiler.
Assessment of the required profitability of metallurgical companies based on a subject-oriented approach
Authors: Galevskiy S G
Published: August 2020

In this paper a developed subject-oriented approach to determining the required return is presented. A subjective risk measure is proposed that takes into account the peculiarities of risk perception by the investor and its awareness. Based on the concept of matching risk and profitability, an equation was developed that reflects the relationship between the subjective measure of risk and the level of profitability. All this allows the determination of the required return to the full individually for each investor to be approached.
Algorithms and software for optimal management of raw materials, fuel and energy resources in blast furnace production
Authors: Spirin N A , Gurin I A , Lavrov V V , Shchipanov K A
Published: August 2020

The structure of optimization model of optimal management of raw materials, fuel and energy resources in the blast-furnace shop of iron and steel works is represented. The following blocks are taken as system basis: 1) calculation of the set of parameters that characterize the thermal, gas-dynamic, slag and blasting modes for every blast furnaces of the shop during the base period; 2) calculation of linearized model coefficients (constants of transferring via different exposure pathways) individually for every blast furnace as well as properties of iron ore raw materials, fluxing additions, blasting parameters, parameters of fuel-enriched blast influencing the technical-and-economic indices of separate furnaces performance, their thermal, gas-dynamic and slag operation modes in the course of blast-furnace melting according to UrFU-MMK blast-furnace production model within the base period; 3) solution of tasks that consider the optimal allocation of raw materials, fuel and energy resources for the project period of blast furnaces operation; 4) analysis of obtained results and providing of recommendations on the optimization of blast furnaces parameters. The developed functional model of optimal distribution of raw materials, fuel and energy resources for the engineering and technology personnel of blast-furnace shop is illustrated; the main functions and interconnections between the separate functional blocks are defined. The functions of created “Optimal management of raw materials, fuel and energy resources in the blast-furnace production” software that is realized in the Microsoft Visual Studio 2017 (C# programming language) programming environment in the form of web application are pointed out. The program product provides the engineering and technology personnel of blast furnace shop of iron and steel works with the opportunity to solve the tasks of optimal distribution of fuel and energy resources (natural gas and oxygen consumption) within the group of blast furnaces in the different technological situations.
Effect of carbon nanotubes on ballistic armour performance of ceramics from boron carbide
Authors: Nepochatov Yu , Kuznetsov V , Bogayev A , Bandin A , Abraamyan A , Kuchumova I
Published: August 2020

The structure, phase composition and properties of hot-pressed mixtures based on boron carbide (B4C) and carbon nanotubes (CNT) were studied. Used boron carbide powder was produced by LLC PIChT and CNTs were made in Russia and Korea. Sintering was carried out in vacuum at 2100 °C and under the pressure of 30 MPa. The samples of ceramics have been obtained with the ballistic armour performance, which is ∼ 26% higher than that of ceramic samples without additives.
Boron electroexplosive alloying of austenite steel
Authors: Ivanov Yu F , Petrikova E A , Teresov A D , Romanov D V , Ivanova O V , Gromov V E , Klopotov A A , Semin A P
Published: August 2020

Studies of phase and elemental composition, defect substructure of surface layer of Cr18Ni10Ti stainless high chromium steel subjected to alloying by electroexplosion method were performed by techniques of X-ray structural analysis, optical and electron microscopy. Titanium and boron were chosen as alloying elements. It has been stated that electroexplosion alloying of steel results in the formation of surface layer having a multiphase submicro-nanocrystallyne structure being characterized by the presence of micropores, microcracks and microcraters. Dependence of phase composition and microhardness of surface layer on relation of titanium and boron masses at electroexplosion alloying has been revealed. It has been found that microhardness of the modified layer is determined by relative masses of titanium borides’ fractions in the surface layer of steel and it may increase 18-fold that in the initial (prior to electroexplosion alloying) state.
Three waves of theoretical architecture and design
Authors: Shakirova Ilgina
Published: August 2020

The history of architecture and design as a complex discipline is no longer seen as a direct evolutionary structure. A more rational approach implies multilinearity, one of the lines of evolution is theoretical.

Alvin Toffler in 1970 developed the theory of three-wave development of society, and, as a result, this influenced the development of design as a whole. Therefore, we are interested in considering the very theory of the three waves of Alvin Toffler and understanding how this development can be considered in relation to architecture and design.

The purpose of the article is to consider the theory of three waves of Alvin Toffler, to compare the development of architecture and the theory of design and history with these waves, thereby identifying the processes that were the starting point for the emergence and development of each wave in these directions. To consider how certain processes that took place in the world have influenced not only the development of society, but also the development of architecture and design.
Problems of transferring penitentiary facilities in the context of sustainable urban development
Authors: Filimonova Larisa , Daubor Anna , Sbitnev Aleksandr
Published: August 2020

The article examines the impact of the location of penitentiary institutions in the historical center of urbanized cities on the sustainable development of the urban environment. The purpose of the research is to analyze the foreign practice of solving the problem in relation to the peculiarities of the Russian legislation, the current norms and rules of the urban development regulations for the development of the territory. The result of this study should be recognized as a generalization of international experience in the field of transferring prison facilities outside of urban development with the re-profiling of penitentiary institutions to meet the needs of urban infrastructure, which allows minimizing the costs of the organization-project Builder, as well as reducing the labor costs of representatives of legislative and Executive authorities when involving departmental lands in economic and commercial turnover. The authors emphasized the importance of applying an integrated approach to solving the raised problem from the point of view of assessing all the risks and possibilities of applying foreign experience in domestic practice. The importance of involvement in the active circulation of problem areas has been proved, which allows you to create a comfortable urban environment that meets the concept of sustainable development of the city in urban planning, economic, social and cultural terms.
Regional architecture of Russia: Kazan - conflicts of the “old” and “new”
Authors: Aidarova Galina , Bashirova Elza
Published: August 2020

The problems of preservation of the architectural heritage and development of the historical center of Kazan, a Russian city on the Volga with a thousand-year history, are considered in this paper.

The main approaches in the architectural practice of Kazan were revealed: 1) restoration of monuments of federal and international significance; 2) eclectic imitations, based on historical styles in the architecture of new objects built in the historical environment; 3) modern architectural and constructive solutions adequate to the current historical time. Signs of a conflict of the «old» and «new» were established: the new buildings imitate the historical examples in stylistic, constructive and functional solutions. The “old” is demolished and rebuilt in materials and structures that do not correspond to the time of its creation.

The ideas that the use of historical styles in modern architectural solutions is unacceptable, and that the need to identifying the authentic heritage of all the periods that the historical city went through were established. Unique architectural solutions should be applied in the construction of new facilities in the historical center.
Adaptation of the shoreline of urban development to special environment conditions
Authors: Kuzminikh Alexander , Korotkova Svetlana
Published: August 2020

This article discusses the need for an in-depth approach to studying the adaptation of the coastline of urban development to special natural conditions. In particular, to periodic repeated flooding and floods in areas of contact with the terrain. As well as the types of technologies and materials that are used to form a protective buffer territory of coastal urban development. The importance vector of water management evolves and shifts from barrier structures against floods and underground pipeline drainage to the natural habitat. Retention pools, wetlands, rain gardens and filter trenches are forming within the city. This has a beneficial effect on the state of the coastline itself and on the attractiveness of this recreational park feature of the city for recreation. In studies based on a factor and comparative analysis of the studied projects in tabular form, it was revealed that in the floodplain relief there are carefully options for barrier fencing. The coastline of the urban development as a buffer zone of land and water should meet the safety and comfort requirements of all inhabitants and be attractive in appearance on both sides.
Reorganization of public courtyards by using the principles of greening space
Authors: Elena Denisenko , Stepan Novikov , Suembike Savelyeva , Aida Gataullina
Published: August 2020

At present, the issue of the architectural space development from the point of view of ecology and green architecture seems to be relevant. Life in the city involves the active use of public spaces and the closest to man is a yard space. The yard is a space for rest, sports and communication between residents. The sustainable development of such spaces has a favourable impact on the entire city. The analysis of the interaction of green spaces on the urban environment shows the importance of the development of the nature in the city. This problem can be solved by greening yard spaces. The article presents the classification of typologies of yard spaces. The yard in the neighbourhood allows considering urban public space as a platform for favorable impact on the resident. The article also presents universal principles of greening public spaces based on analysis of world experience. The formation of yard spaces with the application of green principles is aimed at the development of a comfortable urban environment. Changing the ecology of the city through reorganization of yard spaces contributes to the development of a socially, environmentally, psychologically healthy person.
Risk of road-traffic accidents in the city of Kazan, Russia
Authors: Zagidullin Ramil , Gabdullin Talgat
Published: August 2020

According to the records of the World Health Organization for the year 2018, mortality rate due to road traffic accidents (RTAs) in Russia is equal to 18 RTAs per 100,000 citizens. It ranks Russia the 72th among all the other countries in the world. Statistics of the road traffic accidents occurring between 2013 and 2019 was analyzed in order to reveal the major reasons thereof. The method of levelling of longstanding tendencies by analytical dependencies was used for the evaluation of dynamics and predictions of RTA number. As a result, predicted number of RTAs in 2020 in case of linear dependency was equal to 2118 cases and 1816 cases in case of tendency line. Common RTAs include collisions, hitting of pedestrians and falling of passengers. Most RTAs occur near apartment buildings with death toll rise by 23 % (27 deaths 2018/2017) and 218 % rise (2018/2017) in the number of RTAs near nonresidential buildings.
Seal the top layer of pavement
Authors: Gabdullin Talgat , Zagidullin Ramil
Published: August 2020

The purpose of the study is to improve the quality of the surface course compaction by optimizing the asphalt rollers utilization.

The proposed improvement is aimed at reducing the number of the asphalt roller passes when compacting the top dressing, depending on the types of compaction used, the thickness of the compacted layer and the type of the road topping.

The practicing of compaction methods proposed in this article in the road and construction industry is target-specific to enhance the quality of compaction of the top dressing of the stone mastic asphalt (SMA) and to optimize the number of passes of the compact equipment, depending on the types of compaction to be used.

The vibration compaction was proved to be the most effective method to compact all three grades of SMA.

For all three cases, six passes were proved to be adequate to ensure the standard values of Ky in the mode of vibration compaction.

The length of compaction process reduces as the number of passes is reduced down to six times. This results in saving of up to 20 % in depreciation costs when operating the rollers.
Asphalt concrete pavements of bridges under thermal stress
Authors: Grishm Ilya , Kayumov Rashit , Ivanov Gennady
Published: August 2020

The goal of our research is to develop an optimal model of asphalt concrete pavements of bridges under thermal stress. The development of the model was stimulated by the demand to assess the effect of temperature stresses on the destruction of asphalt concrete pavement of bridges while keeping spending to the minimum, which led to the need to choose, if possible, the simplest model. The search was carried out according to the criterion of compliance with the results of numerical modeling in an elastic setting.

As a result of the study, we have made the following conclusions:

-maximum tensile stresses occur in the upper layers of asphalt concrete;

-the increase in stresses caused by the uneven distribution of temperature over the thickness of asphalt concrete does not exceed 7 % in the elastic setting, and taking into account stress relaxation this can be ignored;

-an increase in the rigidity of the base under the asphalt concrete layer by a factor of 1000 leads to an increase in stresses of not more than 10 % in the elastic setting, which gives reason to use the considered model for both metal and reinforced concrete bridges.
Elastic beam line with noticeable deflection
Authors: Krepkogorskiy Vsevolod
Published: August 2020

Two differential equations are considered in the article. They describe the elasticity line of a curved beam. The second is obtained from the first if the derivative of the deviation function of the beam axis from the straight line is negligible. The question of the proximity of both solutions is studied. The literature considers many options for deviations from ordinary conditions, such as composite beams, complex deformations, too much bending. In our case, the hypothesis of Kirchhoff is supposed to be fulfilled.

The following cases are considered: 1) a beam supported by two supports, and 2) a cantilever beam. The load is distributed evenly. Graphs of solutions are constructed for both equations at different load densities and beam stiffness. A parameter is found, knowing which, we can indicate from the table below how many percent these two solutions differ in. Our task is to find out the limits of application of conventional calculation methods for strong beam bending.
Computational Model of Rib-Reinforced Plate
Authors: Grishin Ilya , Kayumov Rashit , Ivanov Gennady , Petropavlovckikh Olga
Published: August 2020

The article provides a methodology for constructing a calculation model that allows determining displacements in rectangular plates, reinforced by transverse and longitudinal stiffeners. The calculation model is based on the solution of the Sophie Germain’s equation by the Bubnov-Galerkin methods and successive approximations with the representation of the reactive action of the ribs on the plate in the form of a concentrated forces system. Based on the described computational model, the results of the corresponding algorithm implementation and estimation of its convergence are presented. The need to develop a calculation model is explained by the fact that the main cause of cracks in the asphalt concrete coatings of metal bridges with an orthotropic plate is the wheel load. It reaches its maximum values for short periods of time and does not allow the stresses arising in asphalt concrete to relax. At this stage of the development of the calculation model a single-layer plate is considered supported by longitudinal stiffeners. However, since the bridge bed is a multilayer structure, further development of the design model of the multilayer slab reinforced by longitudinal and transverse stiffeners will be necessary. It will help in the joint work of metal flooring and pavement. In addition, it is necessary to take into account the temperature stress factor.
Reinforced concrete beams strengthened with steel fiber concrete
Authors: Oleg Radaikin , Linar Sharafutdinov
Published: August 2020

The aim of the study at exploring joint behavior under load of steel fiber concrete strengthening jackets (SFRC) and reinforced concrete beams at all loading stages. It is necessary for further development of calculation methodology for this strengthening method for members subjected to bending. Experimental results were obtained for assessment of strength, stiffness, crack resistance and failure behavior with a crack propagation pattern for the examined 4 samples (two with strengthening jackets and two reference non-strengthened samples). It has been found that the use of an SFRC jacket 45 mm in thickness with 2.5% fiber content (at the rate of 196 kg per cubic meter) increases the failure load by 20%, the stiffness – 3.4–11 times in the course of loading, and crack resistance – about 2.6 times. The results obtained were compared with the computer simulation in ANSYS PC: the discrepancy between the cracking load, failure load and deflection values for full scale samples and the computer model were found to be within 6.3 %.
Numerical and experimental investigation of prestressed steel-concrete composite beams
Authors: Zamaliev Farit , Bikkinin Emil , Fekir Kahina
Published: August 2020

Prestressing in building structures has been used for a long time. However, the prestressing of structures with a combined cross section, such as steel-concrete structures, has appeared recently. The report is devoted to the structural types of prestressed steel – concrete structures, the description of technical solutions and comparative analysis with known sources. A comparative analysis of the methods of prestressing steel – concrete beams with widespread methods of prestressing reinforced concrete and steel structures is carried out. The article is devoted to prestressed composite beams, the identification of both the stress – strain state of beams of a composite section from prestressing and from operational loads is analyzed. Analytical expressions are given for assessing the strength of prestressed steel – concrete bending elements for different methods of prestressing, and the results of numerical and full-scale tests. Comparisons of the results of numerical and field experiments in the form of graphs are given. In conclusion, satisfactory convergence of various methods for assessing the strength of prestressed beams with experimental studies is noted.
Load carrying ability and optimal characteristics of the roof slab made of profiled sheeting
Authors: Nizameev Vasil , Basharov Fanzil , Nizameeva Luiza
Published: August 2020

The subject of the study is the roof slabs, made of profiled sheetings, supported by bottom truss systems. The profiled sheet, being the upper belt of these structures, experiences longitudinal-transverse bending under the distributed transverse load and a longitudinal eccentric compressive force. Analytical and numerical studies determined the stress-strain state of the profiled sheeting. The dependences of the limiting value of the distributed load on the compressive longitudinal force and the eccentricity of its application are revealed. A technique for optimizing the design parameters of roof slabs have been developed. The studied roof slabs made of profiled sheeting, supported by a truss system, have a rather complicated design with many parameters, on which the performance criteria depend. Studies of the ties between these parameters are quite laborious. Therefore, it is not possible to solve the problems of optimizing these structures by known analytical and numerical methods. To find the rational parameters of the studied slabs, we used the method of phased numerical experiments using simplex optimization. Using this technique, the optimal structural parameters of the slabs with spans of 6-12 m were determined for a given efficiency criterion.
Experimental and theoretical studies of plug joints reinforced concrete columns under transverse force
Authors: Abdrahimova Natalya
Published: August 2020

The analysis of scientific and technical literature indicates the responsibility of joints of prefabricated elements of buildings for structural safety and reliability under the influence of static loads. According to numerous publications by domestic and foreign authors, in frame buildings, the first signs of destruction appear at the joints of elements due to stress concentration. It is possible that at the operation stage the joints will not meet the requirements of reliability and durability due to a number of reasons: the effect of non-design loads, the presence of defects in the manufacture of the joint and installation (non-design reinforcement, cracks in concrete, incomplete filling of joints, etc.). Therefore, ensuring the structural safety of the building and operational suitability by strengthening joints at minimum cost is an urgent task.
Method of calculating the shear stiffness of the flooring under the action of horizontal loads
Authors: Gimazetdinov Aivaz , Kayumov Rashit , Shmelev Gennady , Khaidarov Lenar , Antonov Anatoly
Published: August 2020

This article deals with the issue of calculating combined plywood-metal flooring as a horizontal disk of stiffness, taking into account the structural non-linearity. An analytically obtained method calculating the shear stiffness of the flooring under the action of horizontal loads is proposed.

The task was to derive a three-line correlation - relationship for the fictitious connection operation, based on the constructively nonlinear operation of the flooring. Based on the proposed analytical method of calculating the shear stiffness of the flooring under the influence of horizontal loads, the work of the flooring is modeled as part of the design scheme shown in the figure. The resulting diagram of fictitious relationships was introduced as a characteristic of nonlinear work. In manual calculation in the derivation of the analytical formulas, the compound was considered as a pure hinge. We can conclude that the proposed analytical method of calculating the shear stiffness of the flooring when it is working on a horizontal load, taking into account the structural non-linearity.
Experimental determination of dynamic characteristics and analysis of acceleration of vibrations of pedestrian bridges
Authors: Gimazetdinov Aivaz , Kayumov Rashit , Shmelev Gennady , Khaidarov Lenar , Antonov Anatoly
Published: August 2020

This article discusses the design of pedestrian bridges. When designing pedestrian bridges, engineers are guided mainly by the static characteristics of the types of spans under consideration. If you want to build a load-bearing beam structure of a large span, you cannot lose sight of their relatively large mass and low stiffness due to the length of the bridge. These factors lead to a low natural frequency close to the frequency of pedestrian load, in the form of people passing through this structure, which, in turn, act as recipients of vibrations. The structure is a metal span restructure with two I-beam main beams with a solid sloping wall, an orthotropic plate of the passer-by part below, a calculated width of 44.0 m, a total length of 44.6 m and a pedestrian dimension of 3.25 m. In the course of dynamic tests of the pedestrian bridge span, experimental values of the natural vertical vibration frequencies were determined, followed by the determination of the attenuation decrement. The natural oscillation frequency was 2.0 Hz, which corresponds to a period of 0.5 s oscillation.
About concrete and reinforced concrete corrosion
Authors: Mirsayapov Ilshat , Yakupov Samat , Hassoun Majd
Published: August 2020

This review article provides general information about reinforced concrete corrosion and types of corrosion. The most dangerous consequence of corrosion processes in reinforced concrete is a decrease in the load-bearing capacity of the structure. Corrosion of reinforcing steel is one of the most common damages to reinforced concrete structures. The most dangerous type of rebar corrosion is chloride corrosion, since at a certain concentration of chlorides, the concrete immediately loses its protective properties in relation to the rebar, the corrosion develops locally and deep into the rod, leading to significant losses of its cross-section, often without visible damage to the concrete surface. Types of corrosion: physical corrosion, chemical corrosion, leaching corrosion, magnesian corrosion, carbon dioxide corrosion, sulphate corrosion, hydrogen sulfide corrosion, biological corrosion, electrochemical and electroosmotic corrosion, the destruction of cement stone.

The article provides an overview of the mechanism of reinforcement corrosion, its initiation, progress and factors that expedite the process of reinforcement corrosion. Once the reinforcement corrosion is initiated, it shortens the service life of the structures by cracks initiation, propagation and subsequently spalling of the cover concrete due to expansion of corrosion steel. Corrosion of the embedded reinforcing steel is the most frequent cause for degradation.
Features of information modeling of cultural heritage objects
Authors: Badenko Vladimir , Fedotov Alexander , Zotov Dmitry , Lytkin Sergey , Lipatova Alexandra , Volgin Dmitry
Published: August 2020

This paper focuses on features of heritage objects information modeling and its integration with structural analysis under various types of impacts. We discuss different results of structural analysis based on finite element model (FEM) of the New Hermitage portico. Thanks to laser scanning technology it was possible to collect all the geometric features of this object and generate an adequate mathematical model based on the obtained data. The methodology of finite element model creation based on laser scanning and BIM technologies is proposed. Some interesting results of laser scanning survey and numerical modelling have been discussed. Deviations of the portico’s structural elements have been identified based on the use of laser scanning, BIM and FEA. It has been found out that the displacement of the upper parts of the columns relative to the lower ones in the direction of the facade wall is 4 cm. An intermediate HBIM of the portico (LOD 100) has been created inside Revit. Finite element model with default element size of 300 mm has been created using ANSYS. Directions for further research have been also determined.
Stress-strain state prediction for statically indeterminate system with accounting for malfunctioning of rod elements production
Authors: Efimov Oleg , Salimov Aidar
Published: August 2020

The use of pre-tension as a regulating mechanism in structures that are statically indeterminate rod systems usually implies the absence of initial forces and stresses. It is necessary to take into account its initial stresses from probabilistic positions and adjust the pre-tension parameters accordingly. The laws of distribution of deviations of rod elements or shipment-sized sets of details from nominal sizes and shapes are usually known. The technique of determination of reliable enough value of initial effort in the certain connection of interest of the statically indeterminate system (SIS) because of deviations of rod elements or shipment-sized sets of details from their nominal sizes and forms is presented. Thus, deviations of both rod elements and dispatch brands from the nominal sizes and forms are known to be random variables with symmetric laws of distribution. The task is solved in linear statement with result of research giving the opportunity to determine the value of initial effort using just one static design calculation.
Settlement of the base of clay soil under regime weighting
Authors: Mirsayapov Ilizar T. , Sabirzyanov Danil D.
Published: August 2020

The aim of the article is the development of the theory of strength and deformation of clay soils under conditions of triaxial compression under combined alternating long-term static and cyclic loading. As a result of the research, new experimental data were obtained on the peculiarities of the stress-strain state of clay soils under triaxial compression under combined alternating long-term static and cyclic loading, as well as the development of base sediments of foundation models in laboratory conditions. The significance of the results obtained for the construction industry lies in the fact that experimental studies of determining the changes in the strength and deformability of clay soils under combined alternating long-term static and cyclic loading are necessary for the modernization of engineering methods for calculating sediments and the bearing capacity of foundations.
The assessment of critical vibration values of the construction based on the application of the bifurcation approach in automated geotechnical control systems
Authors: Dorofeev Nikolay , Grecheneva Anastasia , Romanov Roman , Pankina Ekaterina
Published: August 2020

The article deals with the description of the method of building construction stability assessment based on the bifurcation approach and vibration parameters for automated geotechnical control. The use of external vibrational geotechnical noise as a source of a sounding signal in automated systems of geotechnical monitoring is proposed and justified. The interrelation of the influence of vibrational factors on the stability parameters of structures is established and their numerical characteristics are given. A nonlinear model of the stability of the structure is given taking into account the impact of vibration factors. The dynamic behavior of structural elements of the structure with one degree of freedom was modeled, taking into account the load, and a bifurcation diagram was constructed. It is established that in the presence of technogenic vibrational noise, the mass of the upper floors of the building has a significantly greater effect on the stability parameters of the structure. The effectiveness of the proposed approach is proved by comparing the values obtained in the calculation of the mechanical stiffness of the structure according to the standard method using a dynamic coefficient.
Steel timber-concrete beams. Numerical and full-scale experiments
Authors: Zamaliev Farit
Published: August 2020

The first composite beams in the cross section of which concrete and wood were used, were patented at the end of the 19th century. In this article, technical solutions are analyzed based on works of the recent years. New beam designs have been developed. The Russian Federal Service for Intellectual Property (Rus. Rospatent) has issued patents to Kazan State University of Architecture and Engineering (KSUAE) for invention and utility model of new solutions of steel-concrete section beams. Analytical and experimental studies, the experience of using wood-concrete and wooden structures with reinforcement from different materials in the stretched area of the beam are studied. Based on their analysis, new solutions for steel-concrete beams were developed, in which bent steel profiles were used in the stretched zone of the beam, a research program was drawn up.

Numerical studies of steel-concrete beams and thickness variations of bent steel profiles, wall height, pitch, length and diameter of self-tapping screws were carried out.

Experimental studies were carried out using a beam model, the parameters of which are taken from the results of numerical studies. The methodology and test results of the beam are given. The test results are presented in the form of graphs of stresses, deformations, deflections. In conclusion, satisfactory convergence of the results of numerical and laboratory studies of the studied beams of composite section is noted.
Influence of the technological properties of cement-sand mortar on the quality of 3D printed products
Authors: Mukhametrakhimov Rustem , Lukmanova Liliya
Published: August 2020

The results of the influence of cement-sand mortar mobility on quality of hardened composites, made by 3D concrete printing (3DCP), are presented. Four formulations of cement-sand mortar mixes with mobility classes Pk 1, Pk 2, Pk 3, Pk 4 which corresponds to immersion depth of the reference cone of 3.3 cm, 6.5 cm, 8.7 cm, 12.0 cm, respectively, were prepared for testing. It has been established that regulatory framework regulating 3DCP test methods not sufficiently developed and requires further improvement. It was revealed 3D printing of cement-sand mortar mixes with mobility classes Pk 2-Pk 4 on researched 3D printer is possible, however, products have defects and damages. Mortar mobility has a significant impact on structure kinetics and geometric parameters deviation. The lower mobility class is, the higher structure kinetics of raw material mix is, which is due to the early formation of the crystallization structure of hardened composite. Cement-sand mortar with class mobility Pk 2 accepted for further research in the development of adapted raw mixes for 3DCP.
Optimization of the geometry and calculation of the normal vibrations of the dendrimer with amine terminal groups
Authors: Furer Victor
Published: August 2020

The structure of the first generation dendrimer Gi constructed from a hexafunctional cyclotriphosphazene core with six branches -O-C6H4-CH=N-N(CH3)-P(S)< and twelve 4-hydroxyphenethylamine end groups O-C6H4-(CH2)2-NH2 was studied. Structural optimization and analysis of normal vibrations were performed for the Gi dendrimer. The Gi dendrimer molecule has a convex lens structure with flat -O-C6H4-CH=N-N(CH3)-P(S)< fragments and a slightly nonplanar cyclotriphosphazene core. Full optimization shows that the conformation of terminal 4-hydroxyphenethylamine groups O-C6H4-(CH2)2-NH2 with dihedral angles C(13)-C(22)-C(23)-N(6) and C(22)-C(23)-N(6)-H(23): 63.7 and 46.8° is predominant. The flat and anisotropic form of the cyclotriphosphazene core determines the ability of dendrimers to pack with each other in the most likely disk-like form. The spatial distribution of electron density for the core and end groups allows estimating the magnitude of electrostatic interactions on the surface of the dendrimer in the guest-host complexes.
The effect of carbon nanotubes on the curing processes of epoxy-amine compositions
Authors: Yagund Eduard , Potapova Ludmila
Published: August 2020

The effects of the concentration and functionalization of carbon nanotubes on the degree of conversion of epoxy groups in epoxy-amine compositions based on ED-20 epoxy oligomer and the PEPA curing agent are studied. It has been shown that increasing the concentration of functionalized carbon nanotubes (CNT) from 0 to 0.5 % increases the degree of conversion of the epoxy groups during curing at a room temperature. Further increase in concentration CNT of up to 1 % does not effect on the reaction kinetics. For native CNT not established such a relationship. Explains such a pronounced effect on the f-CNT aminolysis reaction kinetics and ultimate degree of conversion of epoxy groups, apparently, the catalytic effect of oxygen-containing groups (hydroxyl, carboxyl, and others) grafted to the surface of CNTs and their direct involvement in the reaction. By optical microscopy showed that the size of the agglomerates of nanotubes were substantially higher in the native systems than in the system with the functionalized nanotubes. These results may be important for the development of creation of epoxy composites modified by nanoparticles.
Modification of clay raw materials to optimize slip casting
Authors: Bogdanov Andrey , Abdrakhmanova Lyaila
Published: August 2020

The effect of surface-active substances (surfactants) on the state of water in clay was studied based on the data of swelling and sedimentation of clay particles in aqueous suspensions. The features of the influence of three types of additives-technical lignosulfonate and hyperplasticizers manufactured by Arkema and Movecreate are considered. When surfactant solutions are introduced into the clay system, an increase in the wettability of clay particles is observed, which promotes the adsorption of surfactant molecules on the surface of the dispersed phase, which depends on the structure of clay minerals and their impurities. Surfactants simultaneously have a plasticizing and structuring effect on the clay mass, leading to intensification of drying in the initial stages and, consequently, to a decrease in shrinkage deformations. The most effective additive is lignosulfonate, the introduction of which in an amount of 0.01 % in a clay suspension increases the fluidity of the suspension, and the mobility of water decreases by more than 3 times than in the presence of hyperplasticizers. The best preservation of the suspension is also ensured in the presence of a plasticizer-lignosulfonate. The main difference in the action of polycarboxylates and lignosulfonate is to change the sedimentation rate of clay suspensions. Modification of clay loam by surfactants leads to improved drying properties, quantified in a decrease in sensitivity to drying.
Bitumen chemical modification by a thermoplastic polymer
Authors: Ayupov Damir , Khakimullin Yurii , Kazakulov Rauf
Published: August 2020

Oil road bitumen was modified by a copolymer of ethylene with vinyl acetate (EVA) and 3-glycidyloxypropyltrimethoxysilane (epoxysilane). These modifiers were simultaneously introduced into the BND 90/130 oil bitumen at a temperature of 165 °C. The components were mixed up during two hours with further isothermal holding at the same temperature during the required period. Epoxysilane crosslinks bitumen with EVA making it possible to obtain an immiscible bitumen polymer binder. The optimal content of EVA is 12 mph, epoxysilane -3 mph with a mixing time of 4 hours. The optimal bitumen polymer binder is characterized by the following properties: softening point of 66 °C, penetration at 25 °C = 50, penetration index of 2.15, brittleness temperature of -22 ° C. Separation is significantly reduced. NMR spectroscopy has revealed that the introduction of the binding agent to the bitumen-polymer binder does not create low-mobile structures. It allows forecasting the high binder stability during storage and transportation.
Modified roman cement
Authors: Nikolay Shelikhov , Ruslan Sagdiyev
Published: August 2020

The purpose of this research is to equip the roman cement with properties exceeding the properties of the known analogies.

Roman cement’s compositions modified by chemical and mineral additives have been developed and proposed. The mode of calcinations of carbonate and clay raw material with high MgO has been optimized. As a result, the durability of roman cement from 15 to 22 MPa has been received. Mineral additives like slag, zeolite breed and clay dust were chosen and used that rose the durability from 22 to 28 MPa. Plasticizers and hardening accelerators were chosen and used that allowed rising the durability up to 35 MPa relatively. A combination of complex additives have been proposed.

To optimize the mode of calcinations and to define a combination of complex additives the method of mathematical planning was used. The dependence of binder’s strength from the temperature, durability of calcinations, saturation rate, type and consistence of modified additives has been acquired.

Modified roman cement has the advantages if compared with known analogies and has the following features: strength 35MPa, normal consistency 30%, setting time is not earlier than 35 minutes, the end is not late than 420 minutes, softening rate is 0.98.

Modified roman cement can be successfully used to produce dry building mixtures (mortar’s strength 5,10, 15 MPA), low strength mortars (strength 5,7.5 MPa) and concret (strength 10, 15, 20, 25 MPa) and other building materials.

Structure of carbonate raw material and clay for the production of roman cement is recommended.
The application of sulfur-asphalt concrete with modifiers in the climatic conditions of Vietnam
Authors: Le Huu Tuan
Published: August 2020

The paper considers the influence of ambient temperature and other weather factors on the properties of traditional asphalt concrete in Vietnam. The advantages of sulfur-extended asphalt concrete with modifiers containing neutralizers for the emission of toxic gases are presented to increase the quality and life of roads and solve the environmental problem of using sulfur-extended asphalt concrete. For calculating the surface temperature of asphalt concrete from the ambient temperature, the method of Yu. N. Kovalev is used (Russia). The weather data for January and July 2015, taken from the hydrometeorological stations of the cities of the respective zones in Vietnam, are used for calculations. The paper presents an experimental setup for determining the intensity of toxic gases evolution and the effect of neutralizers. The widespread introduction in the practice of building progressive environmentally friendly sulfur-containing materials: sulfur-extended asphalt concrete with modifiers, containing toxic gases emission neutralizers, which have higher physical and mechanical properties (wear resistance, etc.) compared to traditional ones at less or equal cost, can open up opportunities to increase quality and lifetime of roads in Vietnam.