The paper analyzes existing 3D printing technologies in the context of application in construction. The experience of 3D printing application in commercial projects is considered. Scientific research on the improvement of various technologies is summarized. 3D printing technologies promising for construction - wire-arc and ultrasonic additive manufacturing - are identified.

Keywords: 3D printing, construction, additive technologies

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 analyzes modern approaches to the use of innovative materials to create an inclusive environment in residential buildings. The paper examines the main problems associated with the obsolescence of building materials, and offers promising solutions based on the use of adaptive and environmentally friendly technologies that enhance accessibility and comfort.

Keywords: inclusive environment, the problem of outdated materials, innovative materials, innovations, trends and prospects, bioplastics, carbon concrete, OLED panels, adaptive structures, accessibility, comfortable environment, design

The article considers the strengthening of the upper chord of the triangular strut system as a method for restoring the bearing capacity of a glued laminated timber element according to the 1st group of limit states. The strengthening allowed us to obtain as a result of calculations a strength utilization factor not exceeding the limit value.

Keywords: triangular spacer system, upper chord, glued laminated timber element, modulus of elasticity, volumetric weight, compressive force, bending moment

The article discusses the use of carbon anchor harnesses to strengthen building structures. Their design features, installation technologies, and key advantages, including low weight, high strength, corrosion resistance, and durability, are described. An overview of existing experiments demonstrating the reliability of anchor harnesses under load, their effectiveness in preventing the stratification of external reinforcement elements and increasing the strength of joints is given. The shortcomings of the regulatory framework and the lack of practical recommendations on the selection and design of anchor harnesses are indicated. The authors emphasize the need for further research to optimize the interaction of the elements of the reinforced structure-external reinforcement-anchor system.

Keywords: anchor harness, carbon fiber, load-bearing capacity, structural reinforcement, teamwork

Determining the deformability of the bearing structures of the coating, as an indicator of the use of the stiffness of the cross-section of the elements, is an urgent task, which is aimed at solving the current work. The purpose of the article is a comparative calculation of frame structures under the assumption of a different coating truss solution. The following types of load-bearing roof trusses should be considered: segment truss, trapezoidal truss, triangular truss. The calculation of frames using wood as load-bearing structures for the total effect of permanent and short-term loads causing maximum vertical deformations is given. In this paper, the coefficients of using the rigidity of truss structures using wood are determined and the dependence of the stiffness value on the type of outline of the coating truss is established. A comparison of the calculation results with the normative maximum permissible values allowed us to establish the most effective type of outline of the wooden roof truss.

Keywords: coating truss, modulus of elasticity, stiffness, upper belt, slant, lower belt, computational study, through-hole construction, segmental truss

The modern building material, slurry infiltrated fiber concrete - SIFCON, has not only high compressive and tensile strength, but also flexibility and ductility. These properties allow it to be used in nodes of building structures that perceive dynamic, shock, explosive loads, friction, as well as in the area of penetration of reinforced concrete slabs by columns. The paper describes experimental studies of the mechanical properties of samples from ordinary concrete and SIFCON. A comparison of the test results showed the superiority of SIFCON strength indicators over ordinary concrete by 2-4 times. For a wide range of specialists and students in the field of construction design, production of building materials.

Keywords: slurry infiltrated fiber concrete, steel fibers, cement mortar, flexibility, plasticity, energy absorption, water-cement ratio, superplasticizer, compressive strength, bending strength, splitting strength

The use of methods for strengthening soils with Portland cement makes it possible to increase the physical and mechanical properties of soils: strength, frost resistance, water permeability, etc. A technical understanding of the processes of structure formation in reinforced soils makes it possible to regulate the final properties and quality of the layers of highways. To describe the processes of structure formation, it is possible to use the theory of contact interactions and the theory of DLFO. The final properties of the reinforced soil are influenced by the following factors: mineralogy and specific surface area of the soil, water content, amount of cement, curing time and method of compaction.

Keywords: stabilized soils, structure formation of stabilized soils, stabilization with Portland cement, properties of stabilized soils

The paper presents the methodology and results of experimental studies of concrete strength under uniaxial and biaxial compression under dynamic impact. The research results are presented in the form of illustrative tables and graphs. The effect of loading rate and the second principal stress on concrete strength is assessed. Ways for further research development are proposed. The studies have shown that under both static and dynamic loading, the type of stress state and the stress level σ2 significantly affect the strength of concrete. The most noticeable increase in strength occurs during the transition from uniaxial compression to biaxial, even with a small value of the second principal stress σ2. With an increase in the level of lateral compression from 0.2Rb to 0.6Rb, the strength of concrete also increases. Thus, the increase in strength at σ2 = 0.6Rb both under statics and dynamics is more than 40% compared to the strength in uniaxial tests with the corresponding loading rate. The type of stress state and the level of lateral compression affect the dynamic hardening coefficient, but to a lesser extent than the loading rate. A slight increase in k_(b,v) (σ_2) compared to kb,v was observed under biaxial compression with a lateral compression level of 0.4Rb and 0.6Rb.

Keywords: concrete, strength, strength criterion, experimental study, uniaxial compression, biaxial compression, dynamic loading, dynamic hardening coefficient

The article discusses the parametric dependencies of cylindrical rod shells in terms of their effect on the state of force and movement of nodes in the grid area. Critical condition factors are analyzed, taking into account the degree of cell filling and the magnitude of the discrepancy between the specified characteristics. The analysis of the formative parameters is carried out and the rational limits of their possible use are established. The factor of taking into account the size of the cell with the location of the rods inside the faces has been introduced. The basic ratios are obtained and the degree of sensitivity of the calculated models to changes in geometric shape is estimated. The limiting angle of the outlined circle has been found, beyond which the operation of the structure is impossible. The level of dangerous increase in the total parameter along the arc at the lowest possible height of the structure has been determined.

Keywords: cylindrical rod shells, mesh area, degree of cell filling, parametric dependencies, force state, stiffness

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

We continue to study the stress-strain state of reinforced concrete bonded and unbonded prestressed beams. In this article, we consider the process of crack formation in such structures, relying on the results of testing experimental reinforced concrete samples of bonded and unbonded prestressed beams, as well as their three-dimensional models created in the Abaqus software complex. The results of calculating prototypes according to current standards are compared with experimental data and calculation of a finite element beam model in the Abaqus complex software complex, on the basis of which recommendations are proposed for calculating the crack resistance of prestressed reinforced concrete bonded and unbonded structures. In the course of the analysis, the following conclusions were made: 1) The real crack resistance exceeds the theoretical and obtained during testing of finite element models. When the effect of reinforcement is taken into account, the discrepancy is considerably reduced, so it should be included in the calculation for a more accurate determination of crack resistance. 2. Unbonded prestressed structures have lower crack resistance compared to classical bonded reinforcement.

Keywords: reinforced concrete beams,prestressed structures, bond, rainforcement, crack resistance

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