The paper studies the problems of heat transfer intensification in shell-and-tube heat exchangers used in the heat supply of buildings. The solution to this problem is to use the circulation of the coolant flow in a pulsed mode, with different frequency pulsations. Based on experimental studies to determine the efficiency of a shell-and-tube water-to-water heat exchanger, a method has been proposed, in accordance with which it has been proved that the pulsed mode, compared to the stationary one, is the most effective in terms of key indicators, such as the heat transfer coefficient and thermal power.

Keywords: intensification, heat transfer, heat exchanger, coolant, fluctuations, efficiency, thermal power

The article studies the thermal conditions in the heating system of a two-storey building of the laboratory building of the Medical Institute. The analysis was carried out on the basis of data obtained from thermograms of heating devices. The study of thermal conditions in a two-pipe heating system is carried out, the actual and estimated power of each heating device is determined, as well as the temperature inside the premises.

Keywords: Coolant regulation, heating system, thermostat, thermal modes, thermogram, coolant, balancing, heating system

The support in the bottom-hole zone of the trunk is a system of rings made of monolithic concrete having a different hardening period, which increases from the face up the trunk and is determined by the duration of the tunneling cycle. The strength and deformation parameters of the concrete support depend on the age of the concrete. Thus, to determine the strength of concrete in the early stages of concrete hardening, various empirical dependencies are used that link the strength of concrete at the design age with the strength at the required age. Based on a series of calculations performed by the finite element method, it was found that the change in the penetration rate does not significantly affect the relationship between stresses and deformations when static equilibrium is reached in the ""support – array"" system, which occurs at a high penetration rate at a greater distance from the bottom of the trunk. At the same time, intensive loading of the support at an early age can disrupt the process of natural hardening of concrete, lead to a violation of its structure, the development of fracturing, which will entail a decrease in the bearing capacity and water resistance of the support, a decrease in its durability.

Keywords: shaft, sinking, support, concrete, stress, deformation, strength, bearing capacity

The problem of removal of combustion products during the reconstruction of existing boiler houses is considered. The issue of determining pressure losses due to friction in steel and brick gas ducts when performing an aerodynamic calculation of gas ducts from gas-fired boilers is considered. Nomograms have been developed that make it possible to determine the specific pressure loss depending on the volume of flue gases and the diameter of the gas ducts.

Keywords: reconstruction, boiler units, aerodynamic calculation, friction pressure losses, gas ducts

The article discusses the history of the creation of heat generators. the main parameters of work and errors associated with the operation of this equipment. a brief description of such parameters as excess air coefficient, chemical underburning is given. on the example of an industrial enterprise in the city of Volzhsky, the relationship between the main indicators of heat generators and the adjustment of a gas burner is shown.

Keywords: energy saving, natural ventilation, the mechanical central zone ventilation system, the single apartment ventilation system, recovery, a planning solution for a building, energy saving, heat generator, boiler unit, gas burner, efficiency

The article examines the modern protection of the population of dual-use facilities, an analysis of it's effectiveness and further protects for the development of solving this problems. Yhe analysis was performed on the example of comparing the provision of the population with buried and other underground spaces in federal districts.

Keywords: protection of the population, infrastructure composition, types of protection, main activities, security of the population, garrison

The problems of modern monolithic construction, namely errors in the installation of sound insulation in monolithic construction, require special attention, since the increased level of noise and vibrations during the operation of premises affects the psychophysical state of a person. Modern enclosing structures are often used in standard solutions without the necessary additional sound insulation. Therefore, in order to develop and introduce effective measures to prevent existing defects in the premises, this paper lists the main factors affecting the high level of permissible noise in the premises. The practice of applied methods and solutions used to improve the sound insulation of individual structures is given. The technology of performing works on the device of sound and noise insulation in residential premises, with an indication of the maximum permissible noise level, is considered.

Keywords: sound insulation, shock noise, residential buildings, noise insulation, air noise, monolithic house, comfortable environment, noise, construction, materials

The article is devoted to the selection of the mobility of the concrete mixture for monolithic densely reinforced reinforced concrete columns directly on the construction site. The main defects in pouring concrete mixtures are described, the causes of their occurrence are analyzed. Empirically, the mobility of the concrete mixture, the technology of laying and the organization of work during the concreting of structures of heavily reinforced columns were selected. Recommendations are given for eliminating defects in monolithic reinforced concrete columns.

Keywords: column, densely reinforced structure, monolithic structure, concrete mix, cone slump, plasticity of concrete, workability, composition selection, monolithic defects

The article is devoted to assessing the influence of errors in the experimental determination of initial data by non-destructive methods for recalculating the bearing capacity of building structures. When conducting an inspecting procedure the technical condition of the building structures that have been in operation for a long time, one of the main tasks is to determine their current operational suitability and predict their durability. The author considers possible errors or inaccuracies in the measurements of the physical, mechanical and geometric characteristics of a reinforced concrete beam (concrete class and reinforcement parameters). The degree of their influence on the change in the bearing capacity of the beam is compared. The conclusion is made about the greatest influence on the actual value of Mult (up to 34.5%) occurs from an incorrect determination of the diameter of the working reinforcement. Errors in determining the class of concrete remain within 1%; accuracy of determining the thickness of the protective layer - within 1.5% and they have a significantly smaller impact on the value of Mult.

Keywords: inspection of existing structures, methods of non-destructive testing, calculating of bending structures, reinforcement parameters

The relevance of this study lies in the fact that the mutual influence of existing transport facilities and the newly erected underground part will be taken into account and the ways to minimize the geomechanical impact on each other will be determined. The subject of the study is the stress-strain state of the system ""structure - massif - structure"". The purpose of the study is to minimize the mutual influence of the subway, the railroad and the underground part of the designed building.

Keywords: geotechnical screen, mathematical modeling, FEM, underground structure, mutual influence, stress-strain state, subway station, minimization of influence

From the standpoint of controlling the behavior of steel floor beams during the operation of a structure, the use of elastically compliant joints in the beam support nodes at the construction stage is considered. Elastic joints are an intermediate link between an ideal hinge and an absolutely rigid connection of the beam ends to the main load-bearing structures and can provide an effective structural solution for connecting elements of any materials with a real reduction in their stress-strain state. The use of resilient joints can be an effective solution for running roofs and ceilings, in load-bearing structures of steel frames, multi-span beam structures. This approach, in principle, is also applicable to beam structures of a through section.

Keywords: system behavior control, steel structure nodes, elastic joints, joint stiffness, analytical solution, finite element method, high-strength fiber

The article is devoted to the architectural and artistic analysis of the vernacular development of Rostov-on-Don in the second half of the 19th century, to identifying the ways of its formation, determining the regional conditionality and systematization of vernacular elements in residential buildings. The scientific novelty of the article is due to the fact that a detailed study of the vernacular buildings of Rostov-on-Don in the second half of the 19th century is being undertaken for the first time, the identification of vernacular features in an ordinary historical building allows us to consider it as an integral component of the regional identity of the architectural heritage that deserves to be preserved.

Keywords: architecture of Rostov-on-Don in the second half of the 19th century, vernacular buildings, Cossack hut, neo-Renaissance, neo-baroque, neo-rococo

According to available literary and graphic sources, the components of urban space, its structural units and their methods of formation are analyzed. The possibility of forming public spaces inside buildings and structures by methods of forming urban spaces is revealed.

Keywords: space, microspace, mesospatial, macrospace, methods of formation, urban structure, public space, levels of spatial organization, public structure, formation of a public complex

The article deals with the need for reconstruction of rehabilitation institutions. The relevance of this issue today is difficult to overestimate, since the vast majority of medical institutions built in the Soviet era are still working, but over the period of operation they have accumulated significant moral and physical deterioration. That is why the issue of their reconstruction is acute, the implementation of which can significantly increase the comfort of incoming patients and ensure the provision of medical care at a high level.

Keywords: reconstruction, construction, operation, rehabilitation institutions

This article attempts to consider some of the features of the calculation and operation of light trusses from rolling corners. Is given brief information about the history of the use of trusses from single corners, their advantages and some disadvantages, as well as the prospects for the use of structures of this type in modern construction practice. Based on the analysis of the design documentation for a number of industrial facilities built over the past two decades in the Khabarovsk Territory, are analyzed the most common mistakes that designers make when developing roof structures using trusses from single rolling angles.

Keywords: farm from single rolling corners; corrosion resistance of elements; eccentricity of the acting effort; loading nodal moment; the value of the coefficient of working conditions; farm support node; additional forces in compressed rods

Studies of building control issues are one of the most topical for industries and human life. The construction industry is one of those. The problem of safe and high-quality unique buildings is closely related to quality construction control.The article discusses the main stages of the documents regulating construction control in the implementation of unique objects, their systematization is given. The schemes of interaction of the main construction participants at the stage of construction and installation works with the obligatory involvement of experts in scientific and technical support of construction for the purpose of further study are presented.

Keywords: construction control, unique buildings, scientific and technical support of construction, construction quality, Camunda BPM

At various stages of the life cycle - during manufacture, transportation, installation and operation, defects and damages may occur that affect the stress-strain state of structures. Some examples of survey the technical conditions of load-bearing structures of enterprises in the city of Ivanovo are given in the article. Defects and damages in operated bending structures are revealed. The results of experimental studies of reinforced concrete beams with initial cracks are presented. The tables show: the beam loading scheme, defect parameters, the location of initial cracks, the main characteristics of materials, as well as experimental data in the form of the relative moment Mult / Mtest, where Mult is the breaking moment of a beam with initial cracks, Mtest is the breaking moment of a similar beam without defects. The degree of influence of defects on the bearing capacity of beams is determined. Empirical coefficients are calculated that take into account the type and parameters of cracks, the cross-section reinforcement coefficient and concrete strength of the beams. A formula for determining stresses in concrete compression zones for beams with cracks is derived based on the theory of destruction mechanics and using experimental coefficients. A method for calculating of reinforced concrete bending structures bearing capacity with defects and damages is proposed. An analysis of experimental and theoretical studies confirming the correctness of this technique is made.

Keywords: reinforced concrete bending elements, beams with cracks, load-bearing capacity, calculation method

This article discusses the features of the pitched roof for typical residential buildings. The design of gable space-roof structures is carried out within the framework of the application of the constructive system of coverage of panel residential buildings with longitudinal load-bearing walls. The formation of the structural form of the cover is solved by the sequential development of the modular system of blocks. The modular system is based on the regular block, which consists of a double-slope deck of bent sheet profiles, fused by folded joints, and a supporting spatial-rod load-bearing system. The design and calculation provisions for the modular unit are presented, taking into account the peculiarities of the layout of the structural form of the cover. The main findings on the use of double-slope roofs are given. The conclusion gives the prospects for the development of the double-slope roofs with the deck of the bent sheet thin-walled profiles. The use of lightweight structure of the roof allows to expand the possibilities of designing the reconstruction of residential buildings of typical construction with a shallow sloping roof without a significant increase in the load on the foundation. The structural solution makes it possible to implement at the construction site an enlarged assembly of the gable roofing, minimizing the use of multiple hand labor and increasing the safety of construction work.

Keywords: configuration of the gable roof, modular block, bent-sheet thin-walled profile, folding seam assembly, spatial rod system

The article provides a solution to the problem of optimizing air ducts with a rectangular cross-section for ventilation and air conditioning systems. Based on the use of the methodology for optimizing air ducts according to the above costs, the optimal proportions of the sides of the rectangular cross-section of the duct are determined, depending on the amount of material costs for the duct device and the cost indicators of its operation. The obtained optimal aspect ratios of the cross sections of the ducts are universal and do not depend on the location of the duct relative to the system fan. These conditions allow, at the design stage of the ventilation system, to assess the degree of optimality of the decisions made on the choice of the dimensions of the cross-sections of the ducts and, if necessary, to make appropriate changes to the design solutions of the ventilation system. The obtained optimality conditions allow them to be included in the calculation programs of the air.

Keywords: fan, air heater, ventilation system, heating and ventilation system, energy, power, energy efficiency, energy conversion, mechanical power flow, thermodynamic system

This article presents the results of a research work devoted to the use of ultrafiltration membranes in the technology of purification of natural waters and wash waters of a contact clarifier unit, as well as design proposals developed on their basis for the reconstruction of existing water treatment plants.

Keywords: membrane technology, ultrafiltration, membrane module, natural water treatment technology, flushing water treatment technologywater treatment facilities, patent research

The article provides an analysis of the possibility of using carbon fiber-based external reinforcement systems to strengthen the load-bearing structures of beam arches along steel beams. The main conclusions based on the results of previously conducted laboratory studies on full-scale samples, as well as the results of the work performed on reference objects are presented. As a result, general conclusions have been drawn regarding the calculation and design, as well as recommendations for further research on the calculation and design of these systems.

Keywords: vaults, prussian vaults, monier arch, external reinforcement, carbon fiber, reinforcement, restoration

Frameless arched coverings are one of the varieties of prefabricated structures for various needs: sports facilities, hangars for various equipment, warehouses for vegetable storage, etc. They are economical compared to other structures, since due to their light weight they do not require massive foundations, compared to frame and wall structures and can be laid with a small depth, which in turn saves on land work. Due to this, they arouse interest in their design and in the development of structural improvements, especially for conditions with a sharply continental climate with high precipitation and strong winds. In this paper, frameless arched coverings made of U-shaped profiles were considered, depending on the span of the coating and on the method of insulation for the sharply continental climate of the Republic of Khakassia. As a result, we have received that constructive solutions are required to strengthen these coatings for large spans, for example 15, 20 and 25 meters, or measures to reduce the snow load on the coating.

Keywords: frameless arched coverings, U-shaped arched profile, sharply continental climate of the Republic of Khakassia, polyurethane foam, mineral wool

This article discusses the advantages and perspective for the use of biogas in the conditions of the Republic of Crimea. The ecological and economic aspects of the use of biogas technologies at winemaking enterprises are touched upon. Describes the methods of using biogas at the winery "Massandra" in the Republic of Crimea. The calculation of the use of natural gas in the boiler house of a winery is made. A calculation was made for the use of biogas in a boiler house. It can be concluded that when using biogas in the boiler house of a winery, fuel needs are fully covered. The surplus of the remaining fuel is proposed to be used in a cogeneration plant to generate electricity.

Keywords: biogas, cogeneration plant, grape plant residue, recycling, interchangeability, granulate, natural gas, grapes, thermal energy, electricity, winery

The article presents the results of experimental studies of crack resistance of inclined cross sections of I-shaped beams using basalt fibre reinforced bars as a transverse reinforcement . The data of previously conducted experiments were studied and the test of own samples was carried out. The beams had the same geometric characteristics and differed from each other in the angle of inclination of the transverse reinforcement, the percentage of transverse reinforcement and the shear span to depth ratio. The influence of variable parameters on the load of formation of inclined cracks and the width of their opening is analyzed. In most cases, the width of the opening of inclined cracks does not exceed the permissible values established by the codes of different countries. The exceptions were mainly samples with the lowest percentage of transverse reinforcement.

Keywords: crack resistance, I-shaped beams, transverse reinforcement, inclined cross sections, shear span, basalt fibre reinforced bars, inclined cracks

The article analyzes the peculiarities of the organization and technology of repair of urban roads in conditions of dense traffic. The technological parameters of pavement repair, considering uneven temperature and peculiarities of compaction of hot asphalt-concrete mixtures, have been substantiated.

Keywords: Urban roads, multi-lane highways, pavement repair, roadway, asphalt pavement, defects