The trends of modern society require a quick solution to the issues of restoration of emergency buildings and structures. New methods of strengthening the load-bearing structures of buildings are aimed at reducing labor costs, the timing of work and the need for complex equipment. In the field of reinforcement of reinforced concrete structures, such methods are composite reinforcement systems. Having proven itself well in working with bendable and compressed elements, there are areas where their use has not yet been studied. One of these is the reinforcement of reinforced concrete girderless floors, in which the protective layer of concrete is broken. This article is devoted to the development of a method of reinforcement with composite materials, where the protective layer of concrete was violated. At the same time, the internal moment of a pair of forces reduces the bearing capacity of the element by about 30%. The paper presents the advantages of the new composite reinforcement method and provides a possible example of its use on a real object.

Keywords: concrete, reinforced concrete, composite material, carbon fiber, carbon fiber lamellas, carbon laminate, flexibility, compressed elements, girderless overlap

The trend in the development of information system design architectures is their complication and movement towards an increasing distribution of functions and components of the system. One of the options for developing decentralized systems are systems based on blockchain technologies. The article discusses an architectural template for applications developed on the basis of blockchain technology. The main elements of a multi-level architecture, which is the basis for building applications of this type, are considered. There are six layers that describe the infrastructure layer, data layer, network, consensus, application and representation. A brief analysis of the main features and differences of the implementation of each of the levels of the architectural template is carried out. According to the results of the analysis, the most specific components for blockchain-based systems are implemented at the level of consensus and data layers.

Keywords: decentralized application, blockchain platform, information system, multi-level architecture, pattern

Based on the review of methods for constructing distribution systems for microwave power amplifiers, a design of a spatial division-summation of power system in the Q-band and a power amplifier based on it is proposed.

Keywords: distribution system, microwave power amplifier, system of spatial division-summation of power

To solve environmental problems related to the disposal of broken bricks, the preparation of new places for building residential complexes, as well as the expansion of the resource base for the production of building materials, clay brick scrap after the renovation of buildings is considered as a major substitute for concrete mixtures. The main physical and mechanical properties of concretes were studied. It has been established that concretes obtained on the basis of coarse aggregate from brick scrap have the properties of concretes based on natural aggregates of the M250-350 grade. The use of scrap clay bricks as fillers requires a special technology for preparing the latter in order to reduce its water demand. The conducted studies have shown that it is expedient to design concrete mixtures based on secondary resources based on a complex binder consisting of Portland cement, finely ground clay brick cullet and hyperplasticizer.

Keywords: clay brick scrap, coarse aggregate, renovation, binder, hardening, concrete mix, concrete, strength

The guarantee of ensuring the safety of people and material assets in the event of a fire requires a careful approach to the design and installation of smoke ventilation. In order to evacuate people from the smoke zone in a timely manner, technical devices with a normalized limit of resistance to fire are installed – smoke valves. To determine the distribution of the pressure of the air flow in the smoke control valve over its cross-sectional area, the method of mathematical modeling is used. With the help of a mathematical model, visual modeling of the distribution of the gas-air mixture flow is carried out, a detailed analysis of hazardous factors is carried out, an assessment of the possible temperature and time of flame propagation, determination of the probable degree of smoke in the interior space and the ways of smoke movement.

Keywords: smoke, fire, ventilation system, smoke protection, smoke valve, mathematical model

A monolithic plate is the most reliable type of foundation. The design is selected if the future building or structure will stand on a site with difficult soil. Three variants of organizational and technological solutions are considered - a ribbed foundation plate a solid foundation slab and a box-shaped foundation plate For each technology, two options for reinforcement are considered - steel and fiberglass reinforcement. The analysis of existing technologies for the installation of a monolithic foundation plate carried out in the first section of this work, showed that the use of these technologies is hampered by a number of factors related to the design and technological features of the object being built. The choice of a rational technology for the installation of a foundation plate is carried out by assessing the influence of organizational, technological and design factors. Based on the results of a comparative analysis of the methods for constructing a foundation plate, it was revealed that the most rational in terms of labor intensity and cost for the structure under consideration, a reinforced concrete plate 15.6x544 m, is technology No. 1 - a ribbed foundation plate using MSC formwork and reinforcement with fiberglass reinforcement. The analysis of the dependencies obtained and the calculation of the coefficients showed that the factors affecting the laboriousness of the installation of a monolithic foundation plate can be arranged in the following order in terms of significance: 1) structural characteristics (the presence of ribs, a solid slab or the presence of voids); 2) thickness of the foundation plate; 3) type of reinforcement used for reinforcing the foundation plate; 4) the area of the constructed plates.

Keywords: monolithic foundation plate, steel and fiberglass reinforcement, factorial analysis, labor intensity and cost of construction, work performance

The design of energy-efficient buildings is based on the analysis of the external climatic effects on buildings for various purposes, the parameters of the air environment inside which are well defined. Climate systems of buildings should neutralize the negative impact of the external environment, in particular wind exposure. It determines both the temperature regime of the room and the purity of the air inside them. The complexity of both theoretical research and the organization of field experiments or blowing models of buildings in a wind tunnel makes it necessary to resort to mathematical modeling of the wind impact on the school building based on the StarCCm+ program. Velocity fields were obtained for different directions of wind load, the excess heat loss of the building in certain directions was determined. The possibility of conducting such studies in a wider range of initial and boundary conditions is shown.

Keywords: aeration of residential buildings, mathematical modeling

The features of the mathematical, algorithmic and software of the developed simulator-training system (STS) for the control of visual modeling skills in the preparation of students in areas of automation, informatization, robotization are considered. The use of STS allows you to automatically generate individual options for practical tasks for the development and analysis of visual models, automatically evaluate the correctness of the tasks performed by students, form advising influences for the student (remarks and recommendations for a better understanding of the topic under study). The use of STS in the process of monitoring the initial skills of visual modeling in students will: reduce the need for manual compilation of a large number of options for tasks by the teacher and subsequent verification of the results of their implementation; improve the quality of education, taking into account the specifics of the areas of student training under consideration.

Keywords: information systems in education, training system, automated control of knowledge and skills, visual modeling, unified modeling language (UML)

The use of information modeling at all stages of the life cycle of a construction object requires a revision of existing approaches to organizing the work of specialists, a more thorough study of the processes of information exchange, the search for new more effective ways of managing information and organizing the use of models. By the period of operation of the constructed object, a significant amount of various data and documents is generated, and during the operation of the building or structure there is a need to collect and analyze significant amounts of information. Damage detection and prediction of structural behavior, search for the current location of a building element can take a lot of time, and a systematic approach to information flow management will ensure an increase in the efficiency of operation services by reducing costs during unscheduled repairs and increasing the life of buildings. This article discusses a model of the integration process of data received or transmitted by Radio Frequency Identification technology tags and data stored and used in an information model. Tags can be placed on critical structures, in complex nodes or on cracks to monitor their disclosure. The approaches to managing information flows depending on the tasks solved at the operational stage, taking into account the preventive maintenance of building elements, are given.

Keywords: radio frequency identification, building information modelling, building maintenance, digitalization, internet of things, industry foundation classes, maintenance and repair, building condition analysis

The purpose of the study is to establish the regularities of a stable hydrodynamic regime by applying a fluoroplastic–containing composite polymer material to the support profile. Research methods: new models have been proposed describing the movement of a lubricant with truly viscous rheological properties in the laminar motion mode in the approximation for a "thin layer", in the working gap of a radial bearing with a support profile having a polymer coating with a groove, the continuity equation. A comparative analysis of the obtained results is carried out, confirming the approximation of the obtained model to practice. As a result of the study, a significant expansion of the possibilities for assessing the operational characteristics of the bearing has been achieved: the magnitude of hydrodynamic pressure, load capacity and coefficient of friction.

Keywords: radial bearing, increased wear resistance, antifriction polymer composite coating, groove, hydrodynamic mode, verification

The article considers the problem of optimizing the scheme of portages in a cutting area. The mathematical model of the cutting area is a polygon - a bounded closed broken part of the plane. The portage scheme corresponds to a root graph (forest, tree) of a special type. We have introduced the concept of covering a polygon with a rooted forest. The cover is interpreted as the possibility of cutting and collecting all the trees in the cutting area while moving the harvester and forwarder along the trails. The trails are laid according to the found covering root forest. Two variants of the algorithm for solving the problem are proposed, which are a modification of the local search. The first algorithm uses the greedy method we described earlier[18] to find the underlying solution. The second algorithm uses the branch and bound method to find the basic solution. Comparative experiments were carried out on polygons sized 12x12 and 18x18. Experimental results show that both modifications of the algorithm improve the basic solution. The first algorithm improves the solution by an average of 11% for a 12x12 polygon and by 24% for a 18x18 polygon.

Keywords: portage schemes, cutting area, polygon covering the root forest, local search, coverage

This paper presents the results of a study of the nature of lifting the tail lift of a truck with a hydraulic drive that supplies the working fluid to the cylinders in series for two positions of the center of gravity of the load on the lifting platform. A diagram of a hydraulic drive is presented, which supplies the working fluid to the hydraulic cylinders in series. Mathematical models describing the operation of the hydraulic drive are compiled according to the scheme. Simulation modeling was carried out using the MATLAB Simulink environment.

Keywords: wheel tyre, suspension module, wheeled vehicle, MATLAB Simulink, mathematical model, modeling

The paper presents the properties and nomenclature of products made of ceramic fiber used for insulating lining in steam reforming furnaces. On the example of the lining of the radiant chamber, the technology of mounting ceramic blankets on anchor studs, which is currently used in the construction and repair of reforming furnaces, is considered. The shortcomings of the existing technology are noted. These include the complexity of the process, the complexity of installation control and the high probability of uneven thermal conductivity of the lining surface due to hidden defects, as well as the spraying of ceramic fiber particles in the air that cause diseases. The nomenclature and technology of installation of insulating lining with ceramic blocks along guide tubes with subsequent resistance welding with the camera body is proposed. The technology will reduce the repair time, improve the thermal conductivity of the camera, reduce the risk of diseases.

Keywords: gas reforming, radiant chamber, insulation lining, ceramic fiber, thermal conductivity of the furnace

This article is devoted to the study of the effect of photocatalytic oxidation together with successive layers of sorbents (shungite, celite) on the efficiency of cleaning the supply air of premises from pollutants of motor vehicles. The studies were carried out with the help of a developed supply ventilation valve with air purification.

Keywords: intensity of ultraviolet radiation, shungite, zeolite, titanium dioxide, adsorption limit, supply air, ventilation valve

Bottom sediments (UP to) are media in which both longitudinal and shear acoustic vibrations can be present. The presence of several velocity components in bottom sediments makes it possible to excite various types of waves, both longitudinal and shear. In this paper, methods of excitation, generation and reception of difference frequency shear waves (RF) created by parametric systems in (DO) in location modes are analyzed. The analysis of their work in the DO is presented, and their comparative characteristics are given in comparison with the excitation, formation and propagation of the field of longitudinal RFCs in the DO. Prerequisites are given for the creation of a parametric profiler working using the method of excitation, generation and location of shear waves in a complex multiphase medium ""water-DO"". A block diagram is presented and the principle of operation of a parametric profiler on shear waves is described. The advantages and disadvantages of this method of location are shown. The conclusion is made about the possibility of creating and ration.

Keywords: parametric antenna, bottom sediments, shear waves, difference frequency waves, parametric profilogaf