Over time reinforced concrete construction tend to lose their strength properties. An important factor in maintaining the integrity of reinforced concrete structures is the compliance of the parameters of the erected structure with its design values and operating conditions. Otherwise, the likelihood of defects such as the formation of cracks in the protective layer and corrosion of reinforcement increases. There are methods for restoring reinforced concrete structures that can return the strength characteristics to the design level or even exceed it.

Keywords: restoration of the protective layer, repair, inhibitor, adhesion, corrosion, penetrating waterproofing, chemical anchor, foundation, shotcreting

The article discusses modern methods of conducting construction control (CS) as part of the implementation of the government program for digitalization of the construction industry. The prerequisites justifying the need for automation of the SC are presented. A review of the software used by Russian construction companies to transfer quality control processes into electronic format was carried out. Based on the completed review, a comparative analysis of the most significant and frequently used software functions is presented. The requirements for them have been formed. They are classified based on their integration into digital models of capital construction projects. This allowed the authors to develop an algorithm for conducting a QC taking into account all the requirements of regulatory documents and the interaction of the main participants in the construction process. It provides for automatic data transfer for the generation of as-built documentation in electronic form, the appointment of persons responsible for correcting defects, their photo and video recording with reference to the 3D model of capital construction projects.

Keywords: digital technologies, automation, regulatory documentation, as-built documentation, quality, construction processes, construction control, information model

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

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 problem of choosing the most optimal gas supply scheme for rural settlements with a complex configuration and natural water barriers is considered using the example of x. Shebalino, Oktyabrsky district, Volgograd region. Four options for gas supply schemes with different numbers and locations of gas reduction points have been developed. The material characteristics and projected cost of design, construction and installation work for each option have been determined. Recommendations on the application of selection criteria are given.

Keywords: requirements for the design of engineering networks, gas supply system, material characteristics, projected cost

This paper presents the concept of using fuzzy control methods in the construction of energy efficient systems based on photovoltaic modules. An analysis was made of methods to improve efficiency in the case of weather in Vietnam on a sunny summer day for photovoltaic modules. The results show that the efficiency of the proposed system is increased by 27.91%, 23.30% and 4.95% compared to the PV module, respectively, with a fixed tilt system, a water-cooled system, and a solar tracking system. The simulation results can serve as a prerequisite for future experimental models.

Keywords: Photovoltaic module, thermoelectric model, solar tracking, water cooling, efficiency, fuzzy logic

In the development of cloud providers, not only the types of services they provide play a significant role, but also fault tolerance to service failures. It is important for a cloud service provider to prepare and configure the server and service for fault-tolerant operation so that the customer works with a high degree of readiness and reliability in the system allocated to him. To prepare such a server, it is very important to think carefully about the architecture of the virtual machine, on which all the necessary means of data exchange and integration for the operation of the service will be installed, and protection against network threats that can disrupt the server's performance will be configured. The purpose of the work is to create a virtual machine architecture protected from network threats, which provides customers with access to the iTOP CMDB system. Despite the fact that there can be any number of customers, the iTOP CMDB system should be provided to each customer with its own version, which he can administer. The user can log in using an Internet browser by entering the name of his organization as a domain. The authors present a demonstration of the iTOP CMDB system, which is located on a virtual machine protected from network threats.

Keywords: virtual machine, architecture, firewall, iTOP CMDB system, server, network threat, network attack, IP address, firewall, request

The analysis of N.N. Pavlovsky's method for calculating the parameters of the riverbed in the branches is given. The reasons for the limitation of this method have been established. The Lagrange transform is used to find the extremum of the objective function for equations of uneven fluid motion, which makes obtaining an equivalent resistance modulus highly visual and easy to use. The results of the experiment are presented.

Keywords: calculation method, multi-node sections of rivers, resistance modulus, N.N.Pavlovsky method

The paper describes the process of modeling 3D structures of synthetic gas burners, with the analysis of the simulation results obtained for several types of models and the selection of optimal modes for them. The main use of the burner is planned for boiler equipment for household needs in private as well as apartment buildings, in the absence of central heating. In addition, the article provides a justification for the thermal parameters at the inlet and outlet of the burner.

Keywords: synthesis gas, combustion, design parameters, combustion chamber, nozzle, modeling

Using numerical simulation, particle deposition in a porous heat exchanger was studied; the mechanism of sediment formation was sinvestigated, and the influence of sediment on the heat flow was assessed. The influence of porous heat exchanger length, dust particle size, and air flow velocity on particle deposition efficiency, particle breakthrough, and heat flux value was studied. Research results have shown that with increasing length of the heat exchanger, the efficiency of dust particle deposition increases, which leads to the formation of sediment. In turn, the sediment reduces the value of the heat flow from the porous heat exchanger. Depending on the length of the heat exchanger and air velocity, the reduction in heat flow is 3.43-7.27%.

Keywords: porous media, heat exchanger, particle deposition, deposition efficiency, particle breakthrough, sediment, heat flow, numerical modeling, computational fluid dynamics, calculation

The production of nitrogen from air using membrane gas separation processes is widely used in many industries. The problem of controlling the gas separation process is associated with multi-loop control using control of several variables. To build a model of a gas separator, a detailed analysis of the gas separation process was carried out in this work. This article proposes a fuzzy logic controller used to match pressure fluctuations and air flow of a gas separator. The performance of the proposed controller was evaluated in comparison with traditional controllers. The proposed fuzzy logic controller makes it possible to increase the accuracy of the gas separation control system and reduce the duration of transient processes.

Keywords: fuzzy logic, controller, gas separation, membrane technology, nitrogen, control system

The article considers a method of automated formation of a training data set for machine learning algorithms for classification of electronic documents, which differs from the known ones by forming training data sets based on the synthesis of clustering and data augmentation methods based on calculating the distance between objects in multidimensional spaces.

Keywords: teaching with a teacher, clustering, pattern recognition, machine learning algorithm, electronic document, vectorization, formalized documents

The concept of a two-dimensional associative masking mechanism, introduced earlier and necessary for further consideration, is used to protect the data of cartographic scenes represented by point, linear and areal objects. The masking mechanism is the basis of associative steganography. In this case, the objects and coordinates of the scene are represented by code words in the alphabet of postal symbols and are masked with the further formation of stegocontainers. A set of masks is a secret key used further to recognize a scene represented in a protected form by a set of stegocontainers. The article deals with the organization of specialized DBMS for the protection of cartographic scene data with the introduction of two levels of such DBMS – server and client. Mono- and multicluster organization of request processing is offered for the server part of the DBMS. Practical recommendations on the use of mono- and multiclusters are given.

Keywords: associative steganography, masking, stegomessage, cartographic databases, parallel DBMS, mono- and multicluster, scene analysis, cryptography, stegostability, information security

The paper proposes a hybrid method of packet routing in a wireless sensor network based on a genetic algorithm that allows you to build a routing table taking into account restrictions on the maximum number of transmissions through each node of the network and, as a result, increase its energy efficiency. The results of experimental studies on BSS with a random configuration of nodes in space are presented and it is shown that the congestion of data packet relay nodes is reduced by 30-40% with an increase in the total length of routes by 10%.

Keywords: wireless sensor network, sensor node, coordinator node, network structure, packet routing, energy efficiency of a wireless network, network model

The aim of the work is to increase the productivity of the iron ore concentrate dehydration process. In the course of previous research, an automated system with individual control of each vacuum filter technological parameters was developed. In this paper, it is proposed to supplement this system of an extreme step regulator hybrid intelligent control unit. A structural and functional scheme and an algorithm for the functioning of the control system have also been developed. The implementation of the developed control system will improve the productivity of the vacuum filter, reduce the wear of the actuators, reduce the specific consumption of energy resources used, and save the financial resources of the enterprise. The proposed control system can be adapted for a large class of technological units of a similar principle of operation used in various industries.

Keywords: iron ore concentrate dehydration, disk vacuum filter, artificial neural network, fuzzy neural network, automated control system, individual regulation, extreme regulator, vacuum, pulp density, vacuum filter productivity sludge moisture