The results of studies of the effect of mineral additives of natural and man-made origin on some properties of fine-aggregate concrete with the introduction of a mineral additive from 10 to 25% of the cement weight instead of either a part of cement with an increase in the value of W/ C, or a part of sand with a constant value of the value of W / C are presented. A slight, up to 3%, change in the average density of concrete was revealed. A decrease in the E-modulus from 4 to 14% was recorded when replacing a part of cement, while an increase in the flexural strength, depending on the dosage, was up to 26% (marshallite) and 6% (chemical water treatment sludge), and a decrease in the compressive strength was from 10 to 22%. When replacing part of the sand, an increase of up to 10% of the E-modulus, the flexural strength from 19 to 38% (marshallite) and up to 11% (chemical water treatment sludge) was recorded. The increase in the compressive strength, depending on the type and dosage of the additive, ranged from 8 to 20%. No significant effect of additives on the porosity of cement stone was revealed.

Keywords: mineral additive, fine-aggregate concrete, flexural strength, E-modulus, shrinkage, water absorption

The problem of synthesizing the parameters of the drive control system of the responsible unit of the construction 3D printer - the screw dispenser of the print head using the method of neuro-fuzzy control is considered. An algorithm for building an intelligent drive control system is described. A training sample is obtained from the data of variables determined as a result of modeling the automatic system control with a continuous proportional-integral-differentiating (PID) regulator. Training of a neuro-fuzzy output system in the MATLAB software environment is performed using the hybrid method a. Transient characteristics of the control system with continuous and neuro-fuzzy proportional-differentiating (PD) regulator are obtained. Direct indicators of the quality of the considered control systems are determined, and an analysis of these results is carried out. The use of neuro-fuzzy control of the screw doser drive of the 3D printer print head made it possible to obtain the desired a transient process confirmed as a result of a computational experiment.

Keywords: 3D printer, screw dispenser drive, print head, concrete mix, transfer function, proportional-integral-differentiating controller, neuro-fuzzy output system

The article discusses the conceptual and practical areas of application of BIM-technologies when performing work on the inspection and restoration of buildings and structures affected by natural and man-made emergencies, as well as when modeling the consequences of natural disasters or man-made disasters. The methods of using BIM software systems in case of fires, earthquakes, floods, floods, as well as in organizing the evacuation of people and assessing damaged building structures are considered separately.

Keywords: emergencies, facility restoration, BIM technologies, man-made disasters, natural disasters, building surveys

The seismic activity of the zones through which the pipelines are laid has always caused serious concern. The analysis of emergency situations on pipeline systems caused by an earthquake revealed factors affecting their stability: longitudinal and transverse displacement of the soil, the effect of soil liquefaction, faults resulting in open cracks and shear deformations. To prevent damage to pipelines during seismic impact, it is necessary to take into account the nature of the impact on the pipeline structure, the required level of safety for this seismic impact. Currently, special attention is paid to structural solutions and materials from which pipelines are made. The conducted studies allow us to form an approach to assessing the operability of polyethylene and steel pipelines in earthquake-prone areas, and on the basis of a comparative analysis of their stability, to make recommendations on the use of pipelines under specified conditions.

Keywords: hydrocarbons, analysis, pipeline, reliability, seismic impact, deformation, composite materials

The method of drawing up a project for the conservation of fuel oil facilities related to hazardous production facilities (HIF) is discussed. An algorithm for the development of a real project for the conservation of structures equipped with technical devices, which are hazardous production facilities in the field of operation of explosive and chemically hazardous production facilities, is given. The article was written on the basis of the completed research work No. 21-216.

Keywords: oil production, conservation project, industrial safety expertise, buildings and structures, technical devices, building structures

The article is devoted to the problem of assessing the safety of buildings affected by natural and man-made accidents and disasters. Within the framework of the work, the stages of assessing the safety of buildings affected by natural and man-made accidents and disasters are presented; measures of a technical and organizational nature were proposed to improve the quality of the assessment of the technical condition and safety of capital construction projects; the main directions for solving the problem of timely organization of the process of assessing the technical condition and safety of buildings affected by natural and man-made emergencies are considered.

Keywords: building safety assessment, natural disaster, man-made accident, man-made disaster, restoration work, emergencies

During operation, the pipeline is threatened by various geological hazards, especially in regions with permafrost, where freeze-thaw disasters have a significant impact on the integrity and safety of oil and gas pipelines. Therefore, at the design and construction stage, it is advisable to analyze various methods of laying pipelines, taking into account the topographic environmental conditions, as well as the effect of frost rise and thaw on the soil of the pipeline foundation. An analysis of the existing design schemes for the construction of pipelines, the conditions for passing the route of the projected pipeline, the characteristics of the pumped hydrocarbons makes it possible to justify the choice of a construction method that can ensure the stable position of the oil and gas pipeline both during the construction period and during its operation.

Keywords: hydrocarbons, analysis, pipeline, construction methods, reliability of pipeline structure, permafrost soil, pile support

As the number of low-orbit satellite constellations (LEOs) increases, the probability of destructive impact from alien spacecraft (SC) will increase. One of the most effective impacts on the NHS is the setting of relay interference, which is an intercepted and delayed signal. This problem can be eliminated by using the "friend or foe" identification system for the spacecraft. At the same time, in order to reduce the probability of selecting the correct transponder signal by a foreign spacecraft, it is proposed to reduce the time spent on calculating the status of the satellite through the use of parallel calculations using codes of the polynomial residue number system (PRNS). A characteristic feature of these codes is the independent and parallel execution of calculations based on the bases of the PRNS. However, this property of the PRNS code can also be used to correct errors that occur during the operation of the identification system. In this case, the algorithm must perform this procedure at a lower time cost. Therefore, the modification of the error correction algorithm, which makes it possible to provide a higher speed of searching and correcting errors, is an urgent task. The purpose of the work is to reduce the time spent on the execution of the procedure for detecting and correcting errors during the operation of the identification system, by modifying the correction algorithm based on the Chinese residual theorem

Keywords: satellite identification system, codes of the polynomial residue number system, positional characteristic, error detection and correction algorithms

A review of methods for calculating microclimate parameters is performed. The possibility of using existing mathematical models to describe the aerodynamic characteristics of ventilation valves and optimize their performance indicators: productivity, hydraulic resistance, density, response time and other parameters that form their efficiency is considered. In order to assess the correspondence of the obtained mathematical dependencies, a physical experiment was conducted. The adequacy of the mathematical model was verified by comparing the results of calculating the parameters of the internal environment in the SolidWorks software and computing complex with experimental data.

Keywords: microclimate parameters, heat and mass transfer, mathematical modeling, heat transfer resistance, experimental study of microclimate, air mobility, valve

This work highlights the architectural and urban planning structure development of Rostov-on-Don in the first half of the twentieth century. The article reflects the main problems identified by architects in the 1920s and 1930s and attempts to solve them in the pre-war and post-war periods. The stages and conditions of restoration of the destruction of the city caused by two occupations during the Great Patriotic War are presented. The restoration concept of 15 RSFSR cities is described. The principles of restoration and their implementation on the example of Rostov-on-Don are considered. The evolution of the city’s architectural appearance is presented. The Triumph of Victory over the Nazi occupiers is shown.

Keywords: urban planning, restoration, architectural appearance, Rostov-on-Don, history of architecture, reconstruction, planning structure, general plan, urban landscaping structure, post-war restoration, preservation of architectural heritage

The article considers one of the ways to improve the reliability of mining equipment, by eliminating sudden failures and reducing the severity of their consequences, based on the use of digital technologies and automated control systems for its technical condition and online diagnostics. It is proposed to use the methods of diagnostics and automated control of the technical condition of power electrical machines, which consist in monitoring the current with subsequent spectral analysis of the recorded signal. The method allows to determine the current technical condition of the engine elements with sufficient accuracy. A high-performance RISC microcontroller of the AVR ATmega16 family was adopted as the constituent elements of the diagnostic complex, which contains a fast Harvard processor, program memory, data memory, input / output ports and various interface circuits.

Keywords: reliability of mining equipment, diagnostics, automated control, current monitoring, spectral analysis

The article presents the results of checking the adequacy of the method of online diagnostics and automated control of the technical condition of the electromechanical drive of the KP21 mining machine with an asynchronous squirrel-cage motor, proposed earlier by the authors. The method of experimental production studies provides for the connection of the measuring complex to the stator winding of one of the phases of the electric motor. The measurements were carried out under various operating conditions of the combine, corresponding to various technical conditions of the facility. A comparative analysis of the technical condition of the diagnosed nodes and the values ​​of the normalized amplitudes of the corresponding frequencies led to the conclusion: the defect must be fixed if the signal amplitude exceeds the value of 10% of the maximum, and the defect is significant and needs to be eliminated if the amplitude value exceeds 30%. To use the obtained research results in practice, an integral nomogram of the correspondence between the operating time of the combine harvester and the amplitude - frequency characteristic of the stator current of the drive motor of the cutting body is proposed. The results obtained are taken as a basis for correcting the schedule of preventive maintenance and maintenance of the cutting body of mining machines KP21 when operating in the appropriate mining and geological conditions.

Keywords: reliability of mining equipment, online diagnostics, automated control, current monitoring, maintenance and repair

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

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

The article considers the directions of development of energy, transport and water facilities through the use of liquefied natural gas.

Keywords: liquefied natural gas, energy, methane, motor transport

The object of the research is the utilization heat exchanger. The purpose of the work is to develop a design of a heat exchanger (HA) used to recover the heat of exhaust gases from a gas turbine unit (GTU) with an increased thermal power. In the process of work, the calculation and numerical modeling of the new design of the heat exchanger was carried out. The result of the research was the design of a gas-air heat exchanger, which requires 6.5% less flow rate of the coolant (exhaust gases) compared to the prototype.

Keywords: heat exchanger, heat utilization, energy efficiency of a gas turbine unit, numerical modeling, gas-air heat exchanger