The article discusses the areas of application of the deformation model and reviews studies related to its use for various design solutions and operating conditions. A method for calculating eccentrically compressed reinforced concrete elements that takes into account second-order effects is presented. This methodology takes into account the current provisions of regulatory documents. A selection of experimental data was made for flexible eccentrically compressed columns. Calculations of bearing capacity and deflections for selected samples were performed. Various forms of concrete deformation diagrams were used in the calculations. Based on comparison with experimental data, conclusions are drawn about the applicability of various types of diagrams for calculating bearing capacity and deflections.

Keywords: deformation model, stress-strain diagram, eccentrically compressed element, flexibility

The article deals with a unique historical structure of Karachay-Cherkessia, the Adiyukh Tower, which several centuries ago was surrounded by an inaccessible wall of the settlement of the same name. In the article, in connection with the history of the construction of the tower, the era is analyzed, and the importance of this building in the life of the population living in the surrounding area is determined. The relevance of the study lies in the fact that the historical monuments of Karachay-Cherkessia remained unstudied until a certain time, although they certainly reflected the life and culture of the people. Reconstructing the past by excavating and studying the ruins left behind by external destruction and located in the North Caucasus has long been a priority for many local (and not only) scholars, particularly archaeologists and historians. The main result of the research was a detailed description of the structural and cultural features of the Adiyukh Tower, which is naturally one of the most important values of the history and culture of Karachay-Cherkessia.

Keywords: Adiyukh tower, Karachay-Cherkessia, legend, North Caucasus, settlement, architectural structure, fortress, loophole, window openings, parapet

The main properties of slag-alkaline binders were studied to determine their optimal composition. The possibility of controlling the properties of binders developed on the basis of phosphorus and blast furnace slag by introducing corrective additives into the aluminosilicate component of slag-alkaline binders, as well as by changing the type of alkaline component, has been experimentally proven. The conducted studies confirm the effectiveness of the use of sulfate-containing alkaline components for the production of slag-alkaline binders. As a result of the conducted experiments, slag-alkaline binders with an activity of 30 to 110 MPa were obtained. The possibility of regulating the properties of the developed slag-alkaline binders has been established. The required binding strength is achieved by adjusting the composition of the aluminosilicate component by introducing additives and the type of alkaline component.

Keywords: alkali-silk binders, slags, optimal composition, basicity, chromium peak, construction materials, reconstruction, work technology

Main tacks of ecology are determine the safety margin of the planet; Identify the parameters that have the greatest impact on the state of the world; Predict the likely outcomes of current economic and industrial policies. Professor  Gaia Herrington concludes that the “standard scenario” is most comparable to the current situation. This has led to the creation of numerous (over 1,500) inventions to reduce environmental threats.   Chemists at the New Jersey Institute of Technology have created a new laboratory method to detect traces of PFAS in food packaging, water and soil sample. Most existing models of the terrestrial biosphere that are used to estimate carbon sequestration account only partially or not at all for the complex mechanisms associated with vegetation, and are at the lower end of the complexity spectrum.

Keywords: environmental threats, limits to growth, inventions on ecology

This article is devoted to determining the main characteristics and properties of concretes made from different concrete mixtures based on Vietnamese materials. A total of 16 formulas of concrete mixtures were studied. Concrete samples were tested to determine deformations under prolonged loading. Based on the data obtained, the main creep characteristics were determined, these are the creep measure C0 and the creep coefficient ϕ, as well as additional characteristics including prismatic strength and the initial modulus of elasticity of concrete. The main purpose of this study was to determine the dependencies of the prismatic strength of concrete Rpr, as its main indicator, in relation to the creep coefficient of concrete ϕ. In conclusion, experimental data on the creep coefficients of concrete ϕ were compared with the normative values found according to SP 63.13330 and conclusions were drawn on the effect of concrete creep on its prismatic strength of concrete Rpr made from concrete.

Keywords: concrete, reinforced concrete, structures, materials, creep, deflections, deformations, prolonged loading

This paper analyzes the shortcomings of the existing organizational and technological documentation, namely the construction organization project and the project of work production. It is concluded that the main task of organizational-technological documentation is to minimize construction risks at the earliest stage, to increase knowledge about the project and to transfer the process of development and decision-making to an earlier stage of construction. As a solution to these problems, it is proposed to consider the use of building information modeling technologies (BIM) in construction, and move to the development of digital construction organization project (4D model of the construction process), which is a digital information model of the capital construction object (3D model), the elements of which are interconnected with the work on construction production. Two projects where the building information modeling technology was applied and a digital construction organization project was developed are considered: construction of an underground tunnel and reconstruction of a power unit of a combined heat and power plant. The advantages of using a digital construction organization project are proved, which makes it possible to forecast the planned duration of works, as well as the duration of works, taking into account the occurrence of risk events, necessary resources and equipment.

Keywords: digital project of construction organization, 4D model, building information modeling, project of construction organization, capital construction object

The article deals with the peculiarities of the study objectives and test methodology for characterization of different contact zones organized in different ways and requiring different methodological approach for specimen fabrication and testing. The steel plate-concrete contact zone organized by stamping on the steel plate requires the use of steel molds to prohibit horizontal movement. The contact zone between the steel plate and the concrete, organized by the stamping on the steel plate requires the use of steel molds to prohibit horizontal movement. The contact zone of two wooden bars organized by epoxy glue with reinforcing fabric placed between the layers of glue is tested for shear without organizing the prohibition of horizontal movement. The contact zone formed at the connection of a steel plate and incompletely gained strength concrete, with the association of steel bars has features of fixing the actual strength of the concrete part of the specimen. The considered methods have both a number of common features and differences, which are taken into account in the proposed methods of fabrication and testing.

Keywords: contact zone, contact characteristics, test methodology, shear tests, stamping, composite construction

Using numerical modeling, we performed studies of the influence of the angle of inclination of the plates of the regenerative heat exchanger element on the heating time and pressure drop. The studies were conducted for models of heat exchange elements with lengths of 6 and 20 mm. Depending on the length of the element, the angle of inclination of the plates was: 10°, 20°, 30°, 40° (at L=6 mm) and 3°, 6°, 9°, 12° (at L=20 mm). At the boundary of the calculation area, the air flow velocity and temperature were established, namely 1 and 3 m/s, and 303 and 973 K. The research results demonstrated that increasing the angle of inclination of the plates helped reduce the heating time of the regenerator by 38.56-49.1%, depending on the length of the heat exchange element, the speed and temperature of the air flow.

Keywords: heat recovery, honeycomb heat exchanger, numerical modeling, calculation, heating time, pressure drop, heat exchanger geometry, angle of plate, air flow velocity, air flow temperature

A large number of pipelines are designed and constructed using steel pipes. The article analyzes statistical data on the corrosion damage of underground steel gas pipelines. The main failures occur in the areas where the insulation is damaged. During operation, the main focus is on controlling the condition of the pipelines' corrosion protection. In addition, it is important to inspect the pipeline route to analyze the condition of its surface. The analysis of underground gas pipeline damage revealed that the majority of corrosion malfunctions are found in pipelines that are 35–40 years old. Therefore, special attention should be paid to pipes that have been in operation for a long time when managing underground gas pipelines. Operational experience has shown that the majority of faults occur in gas networks with a pipe diameter of 100 mm. Moreover, the article presents an analysis of damage to underground gas pipelines, which found that the greatest amount of damage occurs on pipes laid at a depth of 1.5–1.8 meters. This is due to the increased soil moisture at the specified depth, which contributes to the occurrence of corrosion.

Keywords: operation of underground steel gas pipelines, corrosion damage, protection of underground gas pipelines from corrosion

The paper proposes mathematical models that make it possible to describe the electrical conductivity of a nanocomposite based on carbon nanotubes, taking into account the waviness effect and the dispersion index. The model takes into account the contribution of various parameters, such as the concentration of nanotubes, the length, diameter and orientation of the tubes, as well as the electrical properties of the nanocomposite matrix. Using the proposed model, numerical experiments were carried out to evaluate the effects of waviness and dispersion index on the electrical conductivity of the nanocomposite. Comparisons of model data with experimental data are presented, confirming the adequacy and accuracy of the model. The results obtained can be used to optimize the process of creating nanocomposites based on carbon nanoturbines, as well as to increase the efficiency of their use in various fields, including electronics and energy.

Keywords: mathematical modeling, software package, nanocomposites, electrical conductivity, carbon nanotubes, computational experiment

The intensification of technological processes in modern industries is accompanied by an increase in the volume of ventilation and technological emissions, which have an extremely adverse effect on the environment. As is known, wet dust and gas cleaning devices are widely and successfully used to solve this problem. However, the presence of a droplet dispersion of the working fluid in the purified air flow, which can pollute the atmosphere with components captured during the cleaning process, does not allow achieving the required degree of purification. The article presents designs of radial-inertial droplet eliminators, optimized for functional and energy characteristics, proposed for installation in intensive wet dust and gas purification devices for effective separation of droplet moisture.

Keywords: gas-liquid flow, inertial louver separators, separation of droplet moisture, separating elements

The quality of asphalt concrete mixture at the output of an asphalt concrete plant is unstable due to disturbances that we cannot control or control with significant delay. Disturbances may include factors such as inaccuracies in the existing relationships between the properties of asphalt concrete mixture components and the parameters of the technological process with the quality of the finished product. Disturbances can also be attributed to our lack of knowledge about the relationships between individual indicators and the quality of the mixture. Forecasting these disturbances to determine the actual quality at the output becomes a key task. Previously, determining the optimal length of data series for forecasting was a challenging task. Nowadays, with the use of modern technologies, this problem has been successfully solved. In this article, the authors propose an adaptive forecasting method to determine the optimal length of data series. The research results include forecasting error values with and without adaptation. The adaptive forecasting method demonstrated smaller values of mean absolute error (MAE) compared to the non-adaptive forecasting method (where the length of the time series is always equal to 100). This allows for more efficient and accurate prediction of cumulative disturbances, which is critically important for ensuring high and stable quality of asphalt concrete mixture.

Keywords: asphalt concrete, asphalt concrete mixture, disturbance, control system, autoregressive model, forecasting, adaptive forecasting method, optimal length of series, forecast accuracy, mean absolute error

Using numerical simulation, we carried out studies on the effect of the length of a porous heat exchanger on the deposition of dust particles. The heat exchanger models with lengths of 5, 10, 20 and 30 mm were the subject of the studies. At the boundaries of the computational domain, we set the air velocity at 0.1, 1, and 5 m/s and the diameter of dust particles from 10-7 to 10-4 m. Research results have shown that with increasing length of the porous heat exchanger, the efficiency of dust particle deposition increases. This can lead to a decrease in the thermal and hydraulic characteristics of the heat exchanger.

Keywords: porous media, heat exchanger, numerical simulation, calculation, deposition of dust particles, heat exchanger length, air flow velocity, particle diameter, air cooling, microelectronics

The procedure for filling positions of teaching staff of universities belonging to the teaching staff is regulated by federal laws and local regulations. At the same time, it becomes necessary to store and exchange a large number of documents between various participants of competitive events. The aim of the work was to automate the process of holding competitive events and use a common data warehouse, with the help of which it is possible to speed up paperwork, save time and consumables, ensure the safety of storing, transmitting and processing information. The article reflects the obtained results of automation of the competitive selection process at the St. Petersburg State University of Architecture and Civil Engineering.

Keywords: higher education institutions, competitive election, teaching staff, automation

The publication discusses the definition of a shared data environment. The main criteria for choosing SOD are put forward. A generalized analysis of the weaknesses of all existing ODS systems is provided. The article will help you better understand ODS and make the right choice of system.

Keywords: general data environment, design, construction, information, information modeling, ODS, criteria, management, information organization, information transfer