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The purpose of the research Was to study genetic diversity of bovine leukemia virus isolates obtained in the Belgorod Region using restriction fragment length polymorphism method (RFLP). Scientific novelty. Bovine leukosis is one of the most common chronic infectious diseases of cattle in many countries of the world, which causes significant economic losses in the livestock industry. The typing of bovine leukemia virus (BLV), the study of its genetic structure, the evaluation of the mutation vector and a more detailed disclosure of the biological properties of the pathogen represent fundamental and applied value. Methods. The object of the research was 3-4-year-old cows infected with leukemia virus (n = 10), identified by serological methods in disadvantaged dairy farms. The immunodiffusion (ID) test, hematologic studies, PCR, genotyping, statistical processing of obtained data were conducted. Results. Conducted hematological studies determined the stage of the leukemic process in each animal. The target env fragment of the BLV gene (444 bp) was amplificated by 2-stage nested PCR, and this region was genotyped for all studied leukemia virus isolates using the restriction fragment length polymorphism (RFLP) method. In the course of the work, specific regions of the BLV env (gp51) gene, 970 bp long, were also obtained. We have given a primary assessment of the genetic diversity of BLV with the establishment of a genetic group (Belgian genotype according to RFLP). In the course of the work, specific regions of the env gp51 BLV gene, 444 bp long, were obtained. These fragments will be used for further DNA sequencing followed by phylogenetic analysis and determination of amino acid changes in the structure of the surface glycoprotein (gp51) of the bovine leukemia virus. Monitoring studies of BLV genotypes and the study of antigenic changes in the pathogen will allow timely development of the latest means of controlling and restricting the spread of bovine leukosis and improvement of diagnostic serological and PCR test systems.

When calculating the stability and bearing capacity of the panels of the caisson of the wing of an aerospace aircraft, it is necessary to take into account the presence of a heat-shielding coating, which also acts as an elastic base (EB) for the skin. The subject of this work is thin smooth orthotropic rectangular panels with an elastic base that does not perceive compressive and shear flows acting on the panel. The aim of the work is to develop methods for evaluating and designing composite panels associated with an elastic foundation, taking into account the possible geometrically nonlinear behavior under loads close to the design level. Note that the indicated level of loading can be realized only in full-scale static tests in the experimental justification of the strength of the wing structure. The paper presents analytical solutions of a geometrically nonlinear problem by the Bubnov-Galerkin method for rectangular orthotropic panels, taking into account the ER under the action of compressive and tangential forces. Based on the solutions obtained, methods for determining the thicknesses of orthotropic panels are proposed, taking into account two possible criteria: either reaching the ultimate strength stresses in a possible supercritical state, or reaching the limiting values of the deflection amplitude with geometrically nonlinear behavior. The last specified condition is a consequence of the requirements for the strength of the adhesive bond between the orthotropic skin and the heat-shielding layer. The paper considers smooth rectangular orthotropic panels with rigid support along the long sides and hinged support along the short sides.

One of the notable trends in modern engineering practice is the refinement of methods for calculating the building’s structural loads in order to increase the efficiency of building materials’ use, what subsequently will significantly reduce the final cost of the project. The purpose of this article is to study possible ways of increasing work efficiency and reducing the cost of a cellular ceramsite concrete fixed formwork block by modifying its cross section. After modeling the main stresses’ distribution in different sections of the block in the Abaqus program, it was revealed that in the side walls of the modified block, the values of the maximum principal tensile stresses are much larger than those in the old block. This fact allows concluding that the load should be significantly reduced. The development of digital twins’ industry may as well be useful for the use of novel construction materials in the structures subjected to significant loads.

The aim of the research is the use of serological and molecular genetic methods for detecting virus-infected cattle leukemia, as well as determining the significance of PCR in identifying BLV infected calves in the system of antiepizootic health measures. The developed technique for early diagnosis of leukemia in cattle made it possible to accelerate the process of recovery of disadvantaged farms in the Belgorod region by increasing the frequency of studies from 6 months to 2-3 months and an increase in the sensitivity of the agar-gel immunodiffusion test. This, in turn, leads to an increase in the sensitivity of the agar-gel immunodiffusion test and makes it possible to detect, on average, from 8.8% to 20.25% more animals infected with the leukemia virus compared to the standard reaction of the agar-gel immunodiffusion test. The additional use of molecular genetic tests for the detection of proviral DNA of the leukemia virus makes it possible to identify at the early stages of the development of the leukemia process, in calves from 15 days of age, the genomic material of bovine leukemia virus, which will also allow in a shorter time to carry out a qualitative improvement of young cattle in dysfunctional farms.

In this article the influence of aggregate of geopolymer concrete used in concrete printing of buildings and structures, architectural elements on its thermal conductivity is studied. All tests were conducted on device for measuring thermal conductivity called PIT-2 designed to measure the thermal conductivity of building and heat-insulating materials under stationary thermal conditions in accordance with ISO 7345:1987* and ISO 9251:1987. As the fine aggregate most commonly used river sand, quartz sand, ceramic foam, as well as one new coniferous shavings were taken. The results of 4 tests to determine the thermal conductivity of geopolymer concrete with various aggregates are listed in the summary table in the study. According to the test results, the lowest coefficient of thermal conductivity has geopolymer concrete on ceramic foam. In this study geopolymer concrete is considered as the main material for concrete printing of the houses and architectural forms. This material reduces CO2 emissions in the atmosphere.

The authors substantiated the need for digitalization of construction as an imperative of embedding the industry in the ecosystem of the digital economy, taking into account the implementation of the principle of fractality in management. The main digitalization tools have been identified, points of growth in various projections have been determined, and the impact of factors-drivers of digital transformation has been analyzed and assessed. In the process of digitalization of the construction industry, it is necessary, first of all, to ensure the integration of information models of investment and construction projects and existing state information systems. The paper considers the process of integrating the FSIS PC and the BIM design system, identifying the corresponding problem areas and the main stakeholders in the creation of an information system of pricing in construction, and differentiating the possible effects.

Currently, much attention is paid to sustainable development issues, including the search for new environmentally friendly materials and technologies. Such a material is geopolymer, the result of mixing aluminosilicates with an alkaline solution. It has many advantages over conventional concrete, including quick strength gaining. This quality is one of the key ones for the additive manufacturing technology, since the construction mixture for 3D printing must meet certain requirements. The purpose of this article is to determine the effect of fiber on the mechanical properties of geopolymer concrete in terms of 3D printing. In this study the composition of the working mixture with fiber for use in a construction 3D printer was selected and the cone flow diameter for mix and the compressive strength and bending strength of the concrete samples was studied in the age of 1, 3 and 7 days. The highest values of both bending and compressive strength were achieved by samples with 0.5% polypropylene fiber. On the 7th day, the flexural strength was 5.811 MPa, and the compressive strength was 44.035 MPa. The addition of fiber slightly improves the strength of concrete, however, it affects the overall integrity of the mixture and concrete, the technological properties of the mixture improve, the mix becomes more viscous. In the context of 3D printing, the resulting strength values satisfy the need of fast strength gain.

In this article the method of multi-storey concrete printing construction is considered. This way of concrete printing can be effectively used not only in civil and industrial construction but also in road, bridge, tunnel and hydrotechnical construction. The concrete printing in this article is supported by the 3 steps model preparation – designing the model in 2D or 3D in design program, slicing and finally operating the whole process. The main printing element is occurred as extruder working with concrete of different density and other thermal insulation materials. Extruder’s performance was defined by analytical method. The main task of the study determined in comparing of single and multi-extruder storey printing performance with conventional monolithic construction and in defining the most optimal quantity of extruders. It was determined that the quantity of extruders depends on the size of the building and by exceeding one of the parameters the quantity of extruders rises.

Steel joists in general, are widely used in modern building practice and I-joist systems in particular. That is why close attention to the structural concept development or joist construction is paid. That would significantly reduce the material consumption, including changing the flexural member strain-stress distribution. The classic pin joint for supporting steel joist involves a bolted connection in the lower third of the knife-edge height. The constructive solution considered in this article contains additional requirements for the heel joint: tight installation clearance filling between two adjacent joist knife-edges, bolt installation that satisfy the strength condition. These requirements ensure the tensile force transfer from a couple of forces emerging on the pier. We proposed a method for calculating steel I-joist, with the account of the obtained partial restraint effect. This method developed based on numerical calculations of three-dimensional finite element beams models using the binodal unilateral connection, however, with proper justification, the results transfer to the core design schemes. Modeling and calculations are performed in the SCAD Office computer complex. The steel I-joist floor beams studied in this paper have 15 m spans. The restraining effect is estimated based on a results comparison of finite element models numerical calculations of a single joist and two adjacent simultaneously working steel joists. Joist test models are made using shell finite elements with zero Gaussian curvature. As the study result of the operation compatibility of the joist structures heel joint and the analysis of the system strain-stress distribution, a moment redistribution from the span to the heel joint was revealed. With the increase in the span, the restrain effect was found fading. The partial restrain accounting method allows us to assign more economical sections during similar structures designing, due to the introduction of binodal unilateral connection in the heel joint of the joist numerical models. This technique can be used for verification calculations during the technical examination. This paper shows that the bolt junction sections selection for connecting steel joists on a pier can be performed according to the reactions obtained in unilateral connection. Using this calculation methodology in practice for actual construction design provides an opportunity to increase the joist systems’ efficiency and reliability that part of constructional buildings and structures complex.

One of the main issues in block design is the prediction of possible areas of crack formation and their further spread. In structural elements, one of the possible places of crack formation is stress concentrators, because, under an external load, significant local stresses arise in the cross-sections of such parts, which can lead to their destruction. This article discusses possible ways to refine the section to reduce the stress concentration in places of a sharp change in the section of the block. After modeling the distribution of the main stresses in the section in the Abaqus program, it was revealed that with a radius of rounding at the inner corners of the block cells, the maximum values of the main tensile stresses decrease significantly, as does their distribution zone. At the same time, the maximum values of the main compressive stresses increase slightly, and their distribution area increases significantly.

Building a development strategy for large enterprises in modern conditions should take into account not only the established methodology and methodological approaches to strategic management, but also the impact of economic turbulence. At the same time, the paper substantiates the need to develop a strategy in the target focusing of sustainable development as the ability of an enterprise to optimally respond to environmental factors and return to the foresight trend. The authors substantiate the expediency of building an enterprise activity strategy based on foresight even in conditions of economic turbulence, and made a foresight for the development of the railway construction industry. An approach to building a development strategy for a large construction company based on the formation of innovative growth points is proposed, taking into account current development trends and allowing us to identify the key risks of implementing the strategy in order to promptly adjust and implement adaptive management in the process of achieving strategic targets. The proposed strategy has been implemented in RZDstroy JSC, taking into account the influence of the dynamics of the external environment.

The article considers the majority of modern foreign and domestic CAD TP, which solve many problems of technological preparation of production. However, in most systems, the used method of automated design of technological processes remains incomprehensible, the existing organizational structure of pre-production is not taken into account, the correction of actual data (cutting conditions, time standards) does not meet the requirements of modern aviation production. The article proposes to actively use the integrated design method in CAD TP systems.

The technical and economic aspects of energy saving of buildings as an urgent task of the last decades are considered. The conditions for ensuring the efficiency of the economy, the development of technology, the quality and comfort of living, and the preservation of natural resources for future generations are considered. The authors give an analysis of the development of energy consumption depending on population growth and types of energy resources, argue the growing role of energy saving in the context of the projected decline in the availability of natural energy resources at all stages of the building life cycle. The paper proposes a methodological approach to the selection of effective design options for energy-saving measures based on a multi-criteria assessment of technical and economic characteristics, instead of local estimates of the construction cost and consumption of fuel and energy resources at the operational stage.

The positive impact of the virtual labour market development is examined, its capabilities and capacity, as well as the annual effect of the introduction of flexible employment forms, are evaluated. In particular, the features of the Russian labour market, which is starting to use virtual forms, are analyzed: the structure of the areas of employment of remote workers is still narrow - IT, programming; sales finance, accounting; online employment; design; customer support services. This tendency was especially pronounced in the context of a pandemic that changed the attitude of people towards distance work. It is emphasized that in the near future, each employee will have to have digital skills for work and social integration. WEF identifies five separate groups of demanded skills: business, specialized industry, general and soft skills, technical basic skills, technical breakthrough skills. Despite the fact that communication and thinking skills are brought to the forefront, digital skills allow people to create and share digital content, communicate and solve problems, to learn, perform work and social activities in an effective and creative way as a whole. The high level of employees with digital competencies at different levels in the company will provide it with a number of competitive advantages. Neoclassical models that reflect the relationship between economic growth and the growth of human capital are considered. State support for investments in education, research and development, accumulating new knowledge can be considered as the most important endogenous growth factor.

Sustainable development is possible only on the basis of the growth of innovation and the introduction of digitalization in modern conditions. Therefore, it is necessary to speak about the concept of systemic competitiveness, the basis of which is sustainable competitive advantages. This paper is devoted to the problems of forming the competitiveness of construction in the modern economic conditions of the transition to a new technological structure and a digital economy, based on the implementation of sustainable competitive advantages predicted on the basis of foresight and activated by creating “points of innovative growth”.

In this article the influence of aggregate of geopolymer concrete used in concrete printing of buildings and structures, architectural elements on its thermal conductivity is studied. All tests were conducted on device for measuring thermal conductivity called PIT-2 designed to measure the thermal conductivity of building and heat-insulating materials under stationary thermal conditions in accordance with ISO 7345:1987* and ISO 9251:1987. As the fine aggregate most commonly used river sand, quartz sand, ceramic foam, as well as one new coniferous shavings were taken. The results of 4 tests to determine the thermal conductivity of geopolymer concrete with various aggregates are listed in the summary table in the study. According to the test results, the lowest coefficient of thermal conductivity has geopolymer concrete on ceramic foam. In this study geopolymer concrete is considered as the main material for concrete printing of the houses and architectural forms. This material reduces CO2 emissions in the atmosphere.

The authors determined the trends of sustainable development of the complex and the limitations obstructing them. The dynamics of investment and construction complex is considered as a self-organization process basing on information interchange, which allowed presenting a conceptual scheme and lifecycle of the changes in the system as a process of accumulation and dynamics of different innovations. The theoretical assumptions on the essence of the management process were proved thanks to empirical analysis of control system changes of investment and construction complex basing on the model of converging development spiral.

Providing sustainable development of underground construction enterprises in conditions of an unstable environment is implemented through forming and introduction of innovative activities management strategy. In the authors’ view innovations in particular create the basis for sustainable development alongside with forming an integral spectrum of organizational and economic transformations needed by the enterprise. In this article methodic basics of construction enterprise innovative strategies forming using the synergetic approach are given. Implementation of the introduced instruments promotes continuous sustainable development of a construction enterprise on the innovative basis.

In order to develop scientific and methodological tools for sustainable development of the construction complex in Russia the authors justified the concept of economic sustainability, made system components simulation, proposed an assessment method. The article presents proposals of the methodology testing in relation to the definition of the sustainability of a construction company and the construction sector of the economy in Russia. The methodology implementation allows to objectively assess the degree of stability in order to forecast future dynamics while economic conditions changing, to identify priorities for state support and the development of strategies for organizational and economic reforms.

The article deals with the application of combined reinforcement of concrete with steel and basalt fibers. A model of a high-rise building was calculated in the LIRA-SAPR 2013 software. Design and characteristic strength of steel fiber and basalt fiber reinforced concretes to compression and tension and the initial elastic modulus were determined to calculate the model. Comparison of the effect of B40 concrete steel fiber reinforced concrete (SFRC) and basalt fiber reinforced concrete (BFRC) on column reinforcement was performed by comparing the required areas of reinforcement, as well as the percentage of reinforcement, taking into account crack resistance. The total area of reinforcement decreased with the addition of steel fiber by 36.9% and basalt fiber by 39.9%. The percentage of reinforcement also decreased, taking into account crack resistance, from 0.694 for columns with concrete B40 to 0.437 for SFRC columns and to 0.417 for BFRC columns. The addition of fiber increases the strength characteristics of concrete: compressive strength increased by 35.8% and 77.2%, tensile strength by 150.2% and 75.7%, crack resistance by 37% and 39.9%, the initial modulus of elasticity of the material increased by 8.7% and 3.7% for SFRC and BFRC respectively compared with concrete B40.

This article considers ways of the construction printing of models for agriculture, road, civil and also industrial construction using concrete mixtures. For acquaintance with technology, the architectural element with width of layer of 4 cm and 8 cm all model high has been taken with height of one layer of 2 cm. This model has been prepared with use of two packages of the program complexes having different functionality, namely AutoCAD+SheetCAM+Mach3, the second Sketch-Up+Simplify3D. Each software package was used for design of model in 2D or 3D perspectives, division of model into layers, identical on height, by means of technology of slicer, and also for creation of task of the model printing by concrete for the construction printer of model S 6044. Ready mixes for geopolymer concrete have been taken. By results of the printing, comparison of quality of the models printed on the construction printer and technology of each package of program complexes have been made. The printing of models has shown that quality of the printing is identical. In this case, the second method using a bundle of 2 programs (SketchUp + Simplify3D), which allows printing volumetric models of any shape both in plan and in the future, has an advantage.

Existing approaches to assessing the sustainability of an economic system that is in a state of reform or in a transition period (industry, region) have some disadvantages. Some approaches can be applied only to static systems or systems with a stable structure, while others do not have predictive properties. Therefore, there is a need to develop a methodology that can provide a more accurate conclusion about the sustainability and prospects of an industry or region undergoing organizational reform. The authors proposed methodological approaches to assessing the level of stability of the functioning of the region and the industry in terms of deregulation, based on existing ratings, differing in the use of econometric methods.

Wiliness to expand cooperation with European scientists has been triggered by profound study of European standards and codes. Having learnt European standards will make it possible to break technical trade barriers down and make it possible to have common-used design rules for buildings and structures. It is essential to start learning entire array of supporting documents. First of all standards for materials and standards for testing methods should be analyzed. This article deals with research of the European standard technical documentation in terms of specifications and testing methods for concrete mixes and concretes to be compared with the Russian standards.

The features of the application of FRP reinforcement for concrete reinforcement. The results of mechanical tests. Shows the influence of the proportion of glass reinforcement on the physico-mechanical properties of rod fiberglass reinforcement.

Brickwork is one of the most convenient of enclosures. It combines supreme thermal insulation, durability, aesthetic appearance. However, masonry is subjected to plurality of destructive factors, one of which is salt corrosion. Survey of buildings of Saint-Petersburg has been described in this article. Experimental data that proves vulnerability of mortar to salt efflorescence has been obtained. Several solutions of this problem have been recommended and necessity of future researches has been stated.

At the current stage of the economy development the efficient control of the enterprise activity based on the anticipatory adaptation to continuous changes of the environment in tune with the trend of the internal medium dynamic self-organization is the most important prerequisite of the success, so the issues of scientifically substantiated control of changes become especially urgent. The authors have substantiated the essence and comprehensive nature of the process of business changes, and its predominantly innovative character has been determined. The algorithm of controlling business changes at the enterprise based on graph theory methodology has been suggested based on identification of the communication basis of business processes. Using the algorithm enables making scientifically substantiated decisions facilitating achievement of the enterprise functioning goals at some period of time. Based on the algorithm, the authors have developed methodology for optimization of innovation-based organizational enterprise management structure implemented in business practice of RZhDstroi JSC Holding. The results of the suggested methodological tooling validation have shown the appropriateness of the tools in the enterprise business activity.

Based on systematization of methods and criteria of evaluation of competitive ability the present authors have substantiated the comparative principle of competitive ability. Selection algorithm of methodological instrumentarium for analytical competitiveness assessment was developed; a modification of a rating-based model of evaluation of competitive ability with the application of calculation and expert based methods have been presented as consequence. Obtained results in terms of time series provide representativity of arrays of information and significantly increase reliability of assessment. The method was tested by evaluating the competitive ability of several large real estate development companies and that of the construction industry.

The article considers the problem of effective protection of the cooling tower shell using the screen with a ventilated air gap. The aim is to determine the optimal parameters of the air gap. In operation, the calculations were performed showing the effects of temperature conditions and the thickness of the gap on the aerodynamic and thermal modes of operation. The article made conclusions based on the done calculations. The optimum thickness of the gap, provided heating air inlet, which provides the ability to assimilate air moisture throughout the layer and delete it in the atmosphere, which in the future will eliminate condensation on the cold surface of a concrete shell.

The corrosion is one of the main deterioration reasons of structural concrete and reinforced concrete. The corrosion is a consequence of unsatisfactory construction maintenances, poor diagnosis of defects' causes and no fracture control of concrete structures and also incorrect repair specifications and incorrect products and techniques selecting for the repair inevitably lead to the concrete structures' deterioration. The most countries are taking care to developing of the national standards for using as manuals for the protection and repair of concrete structures against corrosion to avoid these negative factors. The article authors are offering the comparative analysis of the harmonized Russian state standards and Eurocodes for the protection and repair of concrete structures against corrosion.

When carrying out design and survey and construction and installation works for such an innovative type of activity as high-rise construction, the problem of personnel qualification becomes urgent. The article poses a research problem, identifies the main reasons for the need for training highly qualified specialists in construction, and suggests areas for improving training. The expediency of development of mentoring system was proved, the corresponding model of interaction between educational institutions and construction enterprises was offered, key interaction effects were evaluated.

The purpose of this article is the development of management process of redevelopment of industrial real estate, based on the criteria-based approach for accepting the form of development. Developing the proposed approach was feasible due to the study of the efforts of foreign experts and experience of the redevelopment projects in Russia. In addition, the article presents the classification of redevelopment of non-residential property, based on three main criteria’s. The proposed algorithm extends the core taking into account the specifics of the three forms of development of objects of real estate (reconstruction, modernization and redevelopment) and is focused on the development of the industrial estate.

One of the important conditions of effective renovation of accommodation in region on the base of realization of high-rise construction projects is attraction of investments by forming favorable investment climate, as well as reduction if administrative barriers in construction and update of main funds of housing and communal services. The article proposes methodological bases for assessing the state of the investment climate in the region, as well as the methodology for the formation and evaluation of the investment program of the housing and communal services enterprise. The proposed methodologies are tested on the example of the Voronezh region. Authors also showed the necessity and expediency of using the consulting mechanism in the development of state and non-state investment projects and programs.

In this article we introduced conducted experiments to determine the basic characteristics of composite reinforcement fiberglass reinforcement on the example of the same diameter, but with a different number of rovings. We have established strength along the reinforcing fiber and the corresponding class of the steel reinforcement.

In this article describe reinforced fiberglass. Fiberglass – fiber or complex yarn, formed from glass. The main application area of fiberglass and fiberglass textile materials is their use as reinforcing elements of fiberglass plastics and composites. For its consideration, conducted laboratory tests were conducted. As a result of the research was chosen the best of the characteristics of fiberglass.