The research aimed to investigate the properties of glass-basalt composite tubes, specifically examining the relationship between structural fractal dimensions, composition, and mechanical properties. Physical experiments were carried out to assess the properties of glass and glass-basalt composite tubes. These tests included measurements of tensile strength, modulus of elasticity, fracture resistance, flexural strength, and additional mechanical characteristics. Fractal analysis of rovings and epoxy binder was performed at the microstructural level to evaluate the impact of structure on mechanical performance. Through predictive modeling of the physical and mechanical properties of glass-basalt composite tubes, an optimal range of properties was identified. This range is defined by specific technological parameters: rovings content of 68–74%, basalt fiber diameter of 7–12 μm, and epoxy binder content of 21–27%. Within this framework, the production of tubes with the following target properties was predicted: tensile strength, compressive strength , and modulus of elasticity.

Keywords: fractal modeling, microstructure, matrix fibers, glass-basalt plastic, composite material, forecasting, strength, fractal dimension, heterogeneity, mechanical properties, composite pipe, glass fiber, basalt, correlation analysis

Technical solutions aimed at preventing and eliminating the consequences of emergency situations in tunnel construction practice (in terms of laying utility lines or subways) are defined. Technical solutions are given taking into account their implementation in the conditions of structures under construction and in operation, characterized by a repeatable and predictable nature of occurrence.

Keywords: building structures, metal structures, energy facilities, stress-strain state, technical expertise

The purpose of this work is to study the thermal stress of the furnace of a fire-tube boiler and its effect on the design of the boiler. To study the effect of thermal stress and furnace proportions on the ratio of heating surface areas, the calculated resistance was tested. Calculations of heat-tube boilers of sectional hot-water boilers with different proportions of the furnace at different thermal loads of the same furnace volume are performed. The calculation of each heating surface is carried out by the method of successive approximations, based in this case on the chord method. In the calculation process, the flue gas temperature at the outlet of the heating surface was first set, and then refined by successive approximations. To reduce the overall balance of the boiler, another global approximation is made when the temperature determined at the outlet of the last heating surface is set at the beginning of the calculation – in the heat balance, where it affects the loss with outgoing gases and the efficiency of the boiler. It is determined that the optimal.

Keywords: energy efficiency, fire-tube boiler, heat supply, thermal voltage, resource conservation

The paper deals with a new composite material for waterproofing the underground parts of buildings and structures. The composite consists of Portland cement, fine aggregate, a complex additive, and chemical additives. Based on experimental data, the main physical and mechanical properties of the material have been determined. The results show that the resulting composite material has high physical and mechanical characteristics and can be used to protect concrete underground structures from groundwater damage.

Keywords: underground structures, durability, protection, waterproofing, composite material, complex additive, strength, crack resistance, adhesion, elasticity

The features of the calculation of nodal joints of frame buildings made of cold-formed steel profiles are considered. The connection of elements of frame buildings made of cold-formed steel profiles for the perception of acting forces is made on bolts using low-carbon steel shapes, the profiles themselves are made of thin-sheet galvanized rolled products. But there are no requirements for the thickness of the shapes and specific thickness values depending on the applied forces in the regulatory documentation, since these compounds are poorly studied in Russia. The calculation of frame buildings made of cold-bent steel profiles and the analysis of nodes with bolted connections was carried out and a method for determining the number of bolts in nodes in two design cases depending on the thickness of the shape was proposed, the need to introduce these requirements into the regulatory documentation for thin-walled structures was shown.

Keywords: cold-formed profile, hot-dip zinc-coated steel sheet, frame building, node, single-bolt connection, shape, crumple, truss, thin-walled structures

The article is devoted to solving the problem of high-precision installation and alignment of kinematic supports on ball rolling bodies, a detailed description of the design solution for precise fixation of ball rolling bodies on a flat monolithic concrete foundation during installation of a seismic insulating support and describes the phased construction of all elements of kinematic seismic insulating supports in the underground part of a high-rise building.A system of seismic-insulating kinematic supports installed in the underground part of a high-rise building is considered. An improved method of high-precision installation of kinematic seismic isolation supports is proposed, which allows to increase the accuracy of installing a seismic support on a system of four rolling elements. The technology of mounting seismic supports on the zero cycle of construction of a high-rise building is described. The advantages are evaluated.

Keywords: high-rise structure, vibration damping, roller seismic vibration compensation system, seismic insulation, high-precision installation of seismic insulating supports

The article considers the prospects for the development of modular construction of buildings and structures in the North Caucasus, analyzes the stages of formation and development of this direction in the light of modern trends. Modular technology in construction is a modern method that involves assembling buildings from prefabricated modules. This approach can significantly reduce the time of construction of buildings, improve their quality and reduce costs. In the conditions of the Stavropol Territory, where there is an increase in the population and the need for housing, such technologies can play a key role in solving the problem of providing citizens with comfortable and affordable housing. This article considers the possibilities of using modular technology in house building. The advantages of this technology are considered in terms of quality, savings, time and environmental friendliness, as well as the flexibility of designs and safety both in the production process and during installation at the construction site. The disadvantages of modular construction are also mentioned, such as the complexity of transporting modules, the need for coordination between production and construction, as well as the high cost of production and standardization. The North Caucasus has unique natural and climatic conditions, which opens up opportunities for the use of modular technologies. Modular housing construction is a fairly efficient construction technology that leads to a reduction in waste and ensures greater precision in the manufacture of components.

Keywords: modular technology in construction, construction production, construction technologies, architecture, environment, module, frame buildings, ergonomics, volumetric modular design, modular construction

The composition of the lightweight plaster mix includes the following components: hydraulic binder, crushed volcanic tuff-scoria (as a fine lightweight filler), reinforcing fiber and synthetic additive. The hydraulic binder consists of Portland cement and finely ground volcanic tuff. Plaster mixes based on volcanic tuff are in demand in regions with a warm or sharply continental climate: high temperatures during the day or low at night, including Ethiopia. The purpose of the research presented in the article was: to form material structure models that allow evaluating the material properties and evaluating the solutions obtained during the implementation of an active experiment. As a result of the experiment, optimal values ​​​​of the main components of the plaster mix based on volcanic tuff were established, which is present in the mixture as a light fine filler and as a component of the hydraulic binder. Modeling of the material structure and engineering interpretation of its properties were carried out.

Keywords: plaster material, tuff-scoria, pozzolanic activity, mathematical modeling, analytical optimization

The article discusses the issues of organizational and technological approaches in the design of facilities to be reconstructed. During the operation of buildings, the reliability of their structures is subject to cyclical changes. The dynamics of loads, as well as damage resulting from operation, can have a significant impact on the strength and durability of construction facilities. The reasons for the technical inspection during reconstruction are analyzed. The diagnosis of structural failure is analyzed. In most cases, emergencies are the result of missed errors at the design stage of the project, construction of the construction site and its operation. To minimize such risks, additional measures are being implemented aimed at quality control at all stages - from design to commissioning. A number of conditions have been identified under which most defects in the design and operation of structures can be prevented even at the stage of development of the reconstruction project.

Keywords: reconstruction, construction and technical expertise, reliability, organizational and technological solutions, defects, quality control, efficiency

The article examines the history of the formation of the architecture of university campuses in the South of Russia (the territory of the modern Southern Federal District and Stavropol Krai) - from the creation of the first universities to the present day. The architectural, stylistic and planning features of campuses of different periods of construction are outlined in the context of the development of domestic architecture. The main factors of development and types of campuses in the South of Russia are identified.

Keywords: university campus, history of architecture, types of campuses, material and technical base

Bamboo as a building material has its own characteristics. It works well in stretching and bending. Bamboo has only longitudinal fibers that are prone to splitting, however these fibers are twisted in a knot. This phenomenon reduces the tensile strength. The mechanical properties of bamboo describe its reaction to physical influences. In general, bamboo has a high tensile strength parallel to the fibers. This article describes the mechanical properties of a bamboo rod depending on the loads, as well as modulus of elasticity of various types of bamboo. This article summarizes the experience of building buildings made of bamboo elements.

Keywords: bamboo, fibers, knot, joint, strength, construction, deformation, stretching, mechanical properties, anisotropic material

In this article, the authors consider the main aspects of maintaining the temperature and relative humidity of the premises of library collections and archive repositories using specialized engineering equipment. The preservation and preservation of material assets is designated as one of the priority tasks of preserving the cultural heritage of Russia. Conservation includes all types of activities and engineering support to guarantee the physical safety of any objects intended for long-term storage, such as library and museum. Currently, both the national program for the preservation of cultural values and the strategy for the development of librarianship have been adopted, including engineering methods for maintaining microclimate parameters for storage facilities and archives of various types: library, museum and federal purposes. Previously, the authors studied the reports provided on the preservation of library collections in Russia and abroad. It has been revealed that in a significant number of cases, the conditions for the preservation of both paper and other funds intended for storage and use as necessary to work with them are not provided. The authors conducted a study and analyzed changes in microclimate parameters when using central air conditioners of various configurations serving two separate sections of one library storage, which is a single-tier room type. The disadvantages of using a simplified basic modification of the central air conditioner based on the results of temperature and relative humidity control in each of the rooms, performed daily from January to June 2022, were confirmed. Variants of changing the configuration of engineering equipment with insufficient functionality with a limited area of the ventilation chamber are proposed.

Keywords: library, engineering equipment, central air conditioning, preservation of funds, conservation, microclimate, storage

One of the important parameters of shaping historical and cultural monuments of the tower type are the dimensions in plan, the thickness of the external walls varying with height, and the angles of inclination of the external and internal sides of the external walls. The article defines the average values ​​of the angles of inclination of the external and internal sides of the walls of tower structures from the vertical using visual and instrumental methods using optical devices, plumb lines, and goniometers. A system of equations is compiled that determines the patterns of shaping cultural heritage monuments of the tower type. An example of calculating the geometric parameters of the designed tower based on the compiled dependencies is considered. The parameters of shaping tower structures must be taken into account when developing design documentation for repair and restoration work, as well as when drawing up process maps for the construction of destroyed or physically worn out wall structures.

Keywords: repair and restoration binders, repair and restoration compositions, hydraulic lime, hydrated lime, gypsum, anhydrite, dolomite, magnesian binders, carbonization, decarbonization, carbonate raw materials, cement raw materials, clays, limestones

The article discusses the results of the analysis of the stress-strain state of the junction of the column and the beam of a monolithic reinforced concrete frame - in particular, the cornice nodes of the outer columns, which have an L-shape. In these nodes, part or all of the tensile (upper) reinforcement of the beam, bending along a certain radius R, passes into the column. The subject of the study is the stress state of concrete in the frame node, as well as the features of the operation of the curvilinear section of the tensile reinforcement. The study of the features of the concrete operation was carried out by setting up a computational experiment. Modeling was performed in the Lira-SAPR software package. The characteristics of the model (finite element scheme) and the main results of the calculation are given - the distribution and numerical values ​​of stresses. To assess the actual work of the tensile reinforcement of the node, an analysis was made of the influence of the loading history of the reinforcement bar - its plastic bending to give the required outline. It was established that the stress state of concrete of a bisecting section differs fundamentally from the stress-strain state of concrete in normal cross-sections of a beam and a column. Taking into account the loading history of the reinforcing bar (preliminary inelastic bending) allowed us to conclude that, with the same tensile force, the deformations of a pre-bent bar exceed the deformations of a rectilinear bar. Obviously, this circumstance leads to an increase in the crack opening width.

Keywords: ramny node, reinforced concrete, reinforcement, stresses, deformations, bisector section, normal section, plastic bending, bending radius, loading history, finite element, Lira-SAPR

Ferrous metallurgy enterprises emit a significant amount of fine dust into the atmosphere every year. The article presents the results of a study performed to determine the dispersed composition of the dust of the ingredients in the emissions of the furnaces of the chipboard steelmaking workshop. The combined use of energy dispersive spectroscopy (EDS) and energy dispersive X-ray spectroscopy of the analysis made it possible to obtain the fractional composition of the ingredients, the values of equivalent dust particle sizes and the integral dependences of the distribution density for equivalent sizes (diameters) were obtained D ingredients containing dust from chipboard furnaces in the samples. Based on the conducted research, it was concluded that it is possible to use certain types of dust collectors in dedusting systems to achieve an acceptable value of their effectiveness to improve the environmental safety of the steelmaking shop.

Keywords: metallurgy, aerosol, dust, ingredient, particle, dust collector, electric steelmaking shop, dispersion analysis, distribution density,average median diameter, dh 50

The specifics of the development of organizational and technological solutions for the reconstruction of outdoor lighting in St. Petersburg are devoted to solving the problems of organizing the reconstruction of outdoor lighting facilities in St. Petersburg. The features of the development of organizational and technological solutions (OTP) for linear objects are analyzed. The specifics and factors of OTR for the production of works in the cramped conditions of a large city, in the absence of the possibility of placing storage sites and temporary buildings and structures, are considered. It is proposed to use production line method of construction for the formation of calendar plans for the reconstruction of the facility.

Keywords: reconstruction, outdoor lighting, organizational and technological solutions, cramped conditions, production line method of construction

Polymer composite materials have been widely used in the construction industry. Currently, these materials are used to restore the operability of buildings and structures, regardless of their functional purpose. To date, the production process is carried out manually and in this regard, there is a need to develop tooling and organizational and technological methods to strengthen structures with polymer-composite materials that increase labor productivity. Due to the insufficient amount of research in this area, the regulatory documentation regulating the procedure for performing quality control of construction and installation works at all stages of restoration of building structures with polymer-composite materials is very limited. In this article, typical solutions for strengthening building structures are considered, various types of polymer-composite materials used in reinforcement are indicated, and the structure of the reinforcement process is described. In addition, an assessment of the time spent in the production of work manually and using small-scale mechanization with the use of additional equipment was carried out. It should also be noted that based on the study of domestic and foreign experience, issues requiring a systematic approach to their solution have been identified. The development and improvement of the regulatory framework, organizational and technological solutions will ensure the further development and application of composite materials in the construction industry.

Keywords: reinforced concrete structures, reinforcement, composite materials, technological solutions, entrance control, operational control, acceptance control

The article presents the results of experimental tests of a number of reinforced concrete eccentrically compressed structures reinforced with composite materials in the longitudinal and transverse directions. During the study, it was found that the composite external reinforcement does not work the same in reinforced concrete structures, but depends on the area of ​​​​the composite materials on the structure. This is due to different stress concentrations along the length of reinforced concrete structures from the action of bending moments and transverse forces. The consequence of this uneven stress state in composite materials is their premature delamination and an underestimation of the overall efficiency of the reinforcement system. This article presents the results of experimental data on the values ​​​​of relative deformations εf of composite materials of reinforced concrete pillars, flexibility λh = 10, tested at a large eccentricity of load application (e0 = 4 cm or 0.32h), going beyond the core of the section. This paper considers various options for composite reinforcement located both in the longitudinal and transverse directions. The deformations were recorded by strain gauges with a 2.0 cm base, at all load levels. As a result, the maximum relative deformations of composite materials were recorded, the most effective zones of transverse clamps location and places where deformation along the fibers did not develop were identified, therefore, the composite in the reinforcement system did not work. The obtained data make it possible to develop the most rational reinforcement options.

Keywords: concrete, reinforced concrete, composite material, carbon fiber, external reinforcement, deformations, compressed elements

The features of the functional-planning and architectural-environmental organization of rehabilitation centers for injured athletes are investigated. A comparative analysis of the functional process of existing rehabilitation centers for the disabled and rehabilitation institutions for athletes is carried out; a system of additional specific measures and functional blocks influencing their architectural, environmental and planning characteristics is identified. For the stabilization, adaptation, recovery and consolidation stages, a specific group of rooms, spaces and equipment is offered, including: individual exercise machines, halls and rooms for group classes, simulators of psychological stress, as well as universal gyms and outdoor playgrounds for demonstration performances of athletes (at the "consolidation" stage). The presented proposals on the functional organization serve as a methodological basis for the formation of adaptive architectural and planning models of rehabilitation centers for athletes.

Keywords: rehabilitation center for athletes, architectural and planning organization, functional blocks

The article examines the history of the development of a children’s educational center and the influence of society’s social needs on shaping the architectural image of educational and cultural leisure institutions.

Keywords: education, school, leisure, culture, social institution, planning, structure, multifunctionality, monastery, university, cultural center, design principles

The existing classification of social objects is considered, using the example of school buildings with a link to the capacity of pupils and the location in settlements of different types. The key external and internal factors that influence the decision of the construction organization to sign a contract for the construction of school institutions are identified, the problem is described - insufficient transport accessibility, lack of resource base, Construction time lag in the implementation of social projects. The influence of the chosen design solution, as well as climatic conditions on project implementation dates was considered.

Keywords: classification of social purpose objects, influence of constructive decisions on the realization of construction object, the ratio of transport accessibility of regions, supply of resource base

The schematic solution of the heating system is analyzed, as well as possible variants of design solutions. A multi-variant hydraulic mode of operation of the heating system of an apartment building is simulated on a simulator stand. The results of the experimental study are presented, and based on the change in design costs and the value of the adjustable pressure drop in parts of the system, proposals are made that allow reducing the cost of water heating systems of buildings under construction, as well as suggesting an increase in the simplicity of adjustment and quality of system regulation.

Keywords: water heating system, oxygen permeability, gas permeability, polymer pipes, gas solubility

To check the efficiency and correctness of the implementation of primary and secondary signal processing algorithms in onboard radar systems for Arctic purposes in the functional tasks of detecting weather conditions that are potentially hazardous to flight, it is advisable to use numerical modeling of radar signal simulators. This is due to the fact that during preliminary tests under adverse weather conditions there is a potential danger of losing control over the flight of the radar carrier, especially in the case of developing unmanned aircraft platforms. In addition, there are very rare weather phenomena, such as wind shear, the detection of which during tests is an unlikely event. All this leads to the fact that the development and debugging of onboard radars for low-altitude carriers that solve the problem of meteorological navigation during flight, it is advisable to carry out the method of semi-naturalistic modeling, using databases for the formation of reflected signals that contain a set of initial parameters that allow imitation either in real time or according to a pre-planned flight scenario and a prepared special set of signal signature records. This article proposes an algorithm for working with a database and subsequent numerical modeling, which allows estimating the necessary spectral components of signal signatures for a pulse-Doppler radar that estimates the radial component of wind speed in each resolution element, which is used for further calculation of the F-factor of wind shear hazard.

Keywords: airborne radar, database, simulation, numerical modeling, meteorological navigation, Arctic, wind shear

In this paper, heat transfer in a staggered tube bundle under steady and pulsating flow conditions is analyzed using numerical simulation. The numerical study was conducted for tube bundles with 5, 10, and 15 longitudinal rows. The Reynolds number Re and the Prandtl number Pr were 3400 and 3 respectively. Flow pulsations were characterized by both symmetrical and asymmetrical reciprocating flow. The effect of pulsations was estimated using the product of the relative dimensionless pulsation amplitude and the Strouhal number A/DSh, which corresponded to values of 0.1, 0.25, and 0.4. The numerical study was conducted using Ansys Fluent. The flow hydrodynamics in the tube bundle was described using the Reynolds-averaged unsteady Navier-Stokes equations. Based on the results of numerical simulation, it was found that the effect of pulsations on heat transfer in the tube bundle varies depending on the number of longitudinal rows. It is shown that an increase in the number of rows leads to a decrease in the Nusselt number ratio in a pulsating flow compared to a steady flow. It is established that the thermal-hydraulic efficiency increases with an increase in the number of rows. It is shown that asymmetric pulsations are more effective than symmetric ones for intensifying heat transfer when taking into account energy costs

Keywords: heat transfer intensification, staggered tube bundle, heat transfer, numerical simulation, flow pulsations