Road construction plays an important role in the infrastructural development of any country. Road infrastructure is a network of roads and motorways that move goods and passengers between and within cities and regions. A well-developed road network contributes to economic growth by providing easy access to markets, reducing transport costs and facilitating more efficient logistics. Roads play an important role in providing accessibility to remote and sparsely populated regions, which contributes to the social and economic development of these areas. Modern motorways provide safer and more comfortable travel for drivers and passengers, and reduce journey times. Roads serve as an important part of the transport infrastructure for the movement of goods. They provide access to ports, railway stations and other transport hubs. Well-developed motorways contribute to the development of tourism as they make tourist destinations and attractions accessible. The article provides a statistical analysis of the construction of federal and regional highways in the period 2021-2023 for eight districts of the Russian Federation. Diagrams of the length of constructed motorways in each district are given, and the main parameters of descriptive statistics are calculated.

Keywords: roads, construction, road infrastructure, motorways, motorways, non motorways, statistical analysis

The effectiveness of advanced pavement defect detection algorithms is considered depending on the data collection devices used, such as cameras, GPR, LiDAR and IMU sensors installed in smartphones. Rational use of these hardware and software tools will allow utilities to identify and eliminate road surface defects in a timely manner, thereby improving road safety.

Keywords: transportation sector, pavement defects, mobile road laboratories, neural network algorithms, computer vision

The problem of concrete strength control when using permanent formwork is considered. The results of the analysis of the experience of using the dependences of concrete strength on temperature-time parameters for forecasting and assessing the strength of concrete during its hardening, including the limits of application of the proposed dependencies, are presented. It is established that the methods of assessing the strength of concrete in a structure by its maturity allow for effective control of the strength of concrete structures concreted in permanent formwork, when there is no access to the concrete surface for non-destructive testing. Recommendations are given on the use of temperature-time dependencies for predicting concrete strength and the equipment used to implement the method, presented on the Russian market.

Keywords: non-destructive methods of testing concrete strength, temperature-time parameters, strength prediction, maturity

The article provides a review and systematisation of works devoted to the application of machine learning for solving problems of research, calculation and design of reinforced concrete structures. It considers the aspects, which are relevant today, related to calculation, design, as well as assessment of the technical condition of objects with the help of various approaches that implement machine learning schemes, including deep learning, ensemble algorithms. It is shown that nowadays in the world construction science this area is rapidly developing and improving. Thus machine learning algorithms solve problems of prediction of design parameters, problems of identification of these or those parameters, defects, damages on the basis of classification algorithms and others. The materials presented in the article will allow specialists to choose the subject area of research more precisely and determine the directions of adaptation and improvement of their own developments in the field of machine learning.

Keywords: machine learning, reinforced concrete structures, regression equations, identification, approximation, artificial intelligence

The article considers the causes of the formation of defects to be evaluated. The methods of obtaining information about the condition of metal corrugated pipes are presented. The main defects arising during the operation of metal corrugated pipes are shown. The most effective methods of assessing the condition of metal corrugated pipes have been determined.

Keywords: corrugated metal pipes, wear, durability, defects, factors, evaluation

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 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 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

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

A comparative analysis of the lighting conditions of school premises was carried out based on design solutions for lighting devices from three Russian lamp manufacturers. All projects were carried out using lighting devices based on recommendations to manufacturers to use their range of lamps to illuminate various school premises. The design was carried out using the DIALux program. Each of the three manufacturers is widely known to specialists and has established itself as a reliable manufacturer of domestic lighting products, ready to offer a full range of lamps for various school premises. A technical and economic comparison of the total present costs for all lighting installations (using the example of one entire school) made it possible to conduct a comparative analysis and determine the most profitable options. An analysis of the current state of the Russian market of lighting devices recommended by manufacturers for classroom lighting has been carried out, their characteristics have been reviewed, and their compliance with current energy efficiency requirements has been assessed. Conclusions and forecasts have been made for the further development of lighting equipment with LEDs for lighting classrooms, based on the need to constantly improve the modern range of lighting devices in terms of their energy efficiency and competitiveness.

Keywords: technical and economic comparison, levelized cost method, comparative analysis, school lighting, lighting device, lighting modeling, energy efficiency

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

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

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 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

This article presents the results of experimental study of the strength of wood and concrete specimens under local buckling by a flat die under short-term loading action. At joint operation of a reinforced concrete slab and a timber beam in the connection there is buckling of timber and concrete elements, therefore it is necessary to know values of strength at these types of loading of timber and concrete. The strength values of timber, concrete on expanded clay aggregate, compression and buckling strength ratios of materials, as well as physical properties of materials according to the requirements of normative documents have been determined. The values of timber deformation were obtained and the graph of deformation dependence on stresses and graphs of deformation growth were plotted; the coefficient of soil stiffness was obtained to determine the strength for local crushing of materials

Keywords: short-term loading, strength, flat die, compression, buckling, coefficient of subgrade reaction, timber, concrete

The article presents a method for determining the stress-strain state of pile foundations for metal supports of power transmission lines during technical examination of power grid facilities in the Far North. An example of calculation using the LIRA automatic software package is given. The most stressed sections of structures are determined. The prospect of using CAD during technical examination of power grid facilities is proved.

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

The article examines modern construction technologies used in the North Caucasus region of Russia and their impact on the efficiency and sustainability of the construction industry. In the context of growing economic and environmental challenges, as well as changing social needs, automation is becoming a key factor in optimizing construction processes and project management. The main focus is on the analysis of the current state of the construction sector in the North Caucasus, its main problems and prospects for the application of new technologies. Innovations such as Building Information Modeling (BIM), robotics, drone technologies, 3D printing of buildings and the use of Internet technologies for monitoring and managing construction processes are considered. Examples of the successful application of these technologies in various projects in the region are described in detail, which allows us to assess their impact on the productivity and quality of work performed. The article also examines the issues of financing the implementation of innovations, training personnel and creating the necessary infrastructure to support automation. The barriers and challenges that contractors and construction companies face when switching to new working methods are considered. Attention is paid not only to economic but also to environmental aspects - how automation can help reduce the impact of the construction industry on the environment. In addition, the paper presents a forecast for the development of the construction industry in the North Caucasus, taking into account new technologies, as well as recommendations for their implementation to achieve sustainable growth and increase the competitiveness of regional construction. Given the specifics and needs of the region, the emphasis is on the possibility of adapting global trends to local realities. Thus, the article emphasizes the importance of innovative automation technologies for the modernization of construction production in the North Caucasus, their role in increasing the efficiency and sustainability of the industry, and also offers strategies for the successful implementation of these technologies in the conditions of a particular region.

Keywords: construction, additive technologies, modern trends, construction production technologies, construction industry, additive technologies, ecology, construction processes, North Caucasus

This paper is the first of a series of works, which the authors have devoted to the analysis of experimental data available in the literature on the influence of various factors on the strength of reinforced concrete monolithic walls of civil buildings. Among them the most significant ones were identified: the ratio of height to wall width, the ratio of height to wall thickness, the class of concrete and the class of reinforcement, the reinforcement scheme and the loading scheme, etc. The most important factors were identified. It is established that the scientists of the past and present in their works, due to the complexity and costliness of experiments, considered a limited small number of factors in a separate study - 1...3, often without taking into account their mutual influence. There is no theoretical interpretation of the results obtained in these works, and no scientific publications summarising the accumulated experimental material have been found. This paper and our subsequent publications are an attempt to eliminate this gap. In the present paper, a classification of all factors is given and the joint action of factor No. 1, which takes into account the H/B aspect ratios, and factor 15c, which takes into account the joint action of vertical and horizontal loads, is considered. The results of this analysis will allow us to make the next step towards the improvement of the methodology for calculating the strength of monolithic reinforced concrete walls, which will take into account the different types of influencing factors as much as possible.

Keywords: reinforced concrete, monolithic walls, experimental data, strength, stiffness, crack resistance, influence factors, geometrical parameters, loads, deformations

This article presents a new method of strengthening reinforced concrete columns using metal and composite materials. The analysis of existing traditional and modern methods of strengthening of reinforced concrete compressed elements has been carried out and their main disadvantages have been identified, taking into account which a new reinforcement method has been developed. This study presents the results of testing the effectiveness of a new reinforcement method, describes in detail the basic schemes, technology and procedure for performing reinforcement work. The results of the conducted experimental studies are presented. The strength of the control samples was compared with the reinforced ones. Proposals have been developed to strengthen reinforced concrete columns with metal elements arranged longitudinally and composite materials glued in the form of clamps with fibers arranged in the transverse direction.

Keywords: steel, reinforced concrete, heavy concrete, test, rack, composite material

The article considers the parameters of rational use of additional support faces of reinforced cylindrical mesh shells. The assessment of the features of shaping has been carried out and the choice of the topology of surfaces within the limits of ensuring the stability of the structure has been justified. Recommended ratios of overall dimensions are proposed and corresponding calculation models are formed. The criteria for determining the sensitivity of the grid are given, taking into account additional support faces and the fulfillment of the conditions of limit states. A range of acceptable values of curvature and geometric parameters for the creation of reinforced cylindrical mesh shells has been obtained. The effect of increasing stiffness and increasing height on the performance of the mesh surface is analyzed. The characteristic patterns of changes in nodal deviations and internal force factors of vulnerable zones are revealed.

Keywords: cylindrical mesh shells, additional support surfaces, shaping, parameter ratios, reinforcement, stability

The article provides a brief overview of foreign experience in the application of information modeling technologies (BIM) in "green" construction. The work carried out a scientometric assessment of publications on the topic of BIM in "green" construction. As a result of the review, it was found that BIM has recently been increasingly used in the field of "green" construction, forming a new stage of resource efficiency and minimizing the negative impact on the environment.

Keywords: information modeling technologies, "green" construction, sustainable development, building life cycle, resource management, energy efficiency and environmental friendliness

Modern designs of water heating systems are saturated with different types of regulators, but their use is more often justified not by a systematic approach, but by solutions necessary for the operation of the system in its individual parts. The objectives of the presented work are to obtain and systematize experimental data to study the variable hydraulic mode of operation of horizontal water heating systems using apartment stations. In this paper, a problem in the field of development of modern water heating systems that needs to be solved is formulated. The analysis of the schematic solution of the heating system, as well as possible design options, was carried out. A simulation of the multivariate hydraulic mode of operation of the heating system of an apartment building was carried out on the simulator stand. The results of an experimental study are presented, and based on changes in design costs and the value of the adjustable pressure drop in parts of the system, proposals are made to reduce the cost of water heating systems for buildings under construction, as well as suggesting an increase in the ease of setup and quality of system regulation.

Keywords: balancing fittings, hydraulic characteristics research, water heating system, automatic regulators

The development of methods for calculating structures made of ultra high-performance steel fiber-reinforced concrete (UHPC) in terms of strength and deformations is an important step towards the introduction of this innovative material into the practice of design and construction. This paper presents the results of finite element modeling of the operation of UHPC I-beam in the area of action of shear forces. The SMM model integrated in the OpenSees framework application is used for the walls of beams under conditions of flat stress. The authors have added new classes of materials that implement the averaged deformation laws of UHPC (with and without fiber) and the reinforcement placed in it. The calculations showed good convergence with the authors' own test results of the UHPC I-beams, as well as with the results of experiments by other researchers.

Keywords: shear strength, shear force, ultra high-performance steel fiber-reinforced concrete, I-shaped beams, OpenSees

The choice of the method of force calculation of building structures is preceded by an analysis of the static determinacy and immutability of the rod system using structural formulas, while for different types of structures - for beams, trusses, frames, arches, etc. - sources offer different formulas. It is shown that for the structural analysis of all rod systems it is sufficient to determine the degree of structure anomaly using the formula of P.L. Chebyshev. The development of the linear-monad theory of structure makes it possible to formalize the dependence of the number of rods and hinges on the number of external and internal contours in the synthesis of both normal and anomalous structures

Keywords: beam, truss, frame, arch, structure, analysis, synthesis, immutability, definability, degree of anomaly, rods, system, contour, monad, hinge