The article discusses the methods and approaches developed by the authors for the recommendation system, which are aimed at improving the quality of rehabilitation of the patient during respiratory training. To describe the training, we developed our own language for a specific subject area, as well as its grammar and syntax analyzer. Thanks to this language, it is possible to build a devereve describing a specific patient's training. Two main methods considered in the article are applied to the resulting tree: "A method for analyzing problem areas during training by patients" and "A method for fuzzy search of similar areas in training". With the help of these methods, it is proposed to analyze the problem areas of patients' training during rehabilitation and look for similar difficult areas of the patient to select similar exercises in order to maintain the level of diversity of tasks and involve the patient in the process.

Keywords: Recommendation system, learning management system, rehabilitation, medicine, respiratory training, marker system, domain-specific language, Levenshtein distance

The paper describes the procedure for conducting a competition for regression models based on statistical data for the East Siberian Railway. At the same time, it is assumed to build a set of additive alternative versions of the model with the subsequent choice of the best option based on the involvement of a number of adequacy criteria. The unloading of wagons is singled out as the output variable of the model, and the input variables are: the average gross weight of a freight train, cases of failures of technical means of the 1st – 2nd category of operational nature, the working fleet of freight wagons. The implementation of the model competition allowed us to build over two hundred alternative options, from which the best alternative was selected using multi-criteria selection methods based in this case on a continuous criterion of consistency of behavior.

Keywords: railway transport, mathematical model, regression analysis, least squares method, model competition, adequacy criteria, multi-criteria selection

The article should choose a metal truss based on the initial data for pitched roofs. Defined maximum loads and deflections in each truss. On the analysis of the residually deformed state of the truss, it was concluded that the most authentic in terms of the structural members of the truss. Recommendations are given for the design of load-bearing structures of roofs on metal trusses in the manufacture of a shed roof structure.

Keywords: truss, effort, designing, deflection, roof, load, static calculation, displacements, trapezoidal truss, Molodechno truss

This article analyzes two systems of logistics for construction organizations based on the concept of Material Requirements Planning (MRP) and Just-in-Time (JIT). The main advantages and disadvantages of each system were investigated, and which of them are most effective in the current conditions were determined. Possible options for improving MTO systems are considered, as well as recommendations for the introduction of MRP and JIT into the practice of construction organizations to increase efficiency and reduce costs are proposed. The article will be useful for specialists in the field of construction and logistics, as well as for everyone who works in the field of management and optimization of business processes.

Keywords: logistics, Material Requirements Planning concept, Just-in-Time concept, construction project planning

This article presents the results of a study of the process of decompaction of clay soils when they are used in soil structures. To study this issue, the following factors were chosen: the dimensions of the test samples, the amount of load on the samples, swelling when soils are moistened and shrinkage when they are dried, and the loss of strength of the samples during their decompaction was also estimated. All studies with soils were carried out in laboratory conditions. In the course of the research, dependences of relative decompaction on vertical load and changes in shear forces depending on the degree of moisture during decompaction of soils were obtained. The main conclusions of the work are given.

Keywords: clayey soil, decompaction of soils, mineralogical composition, optimal soil moisture content, density of the soil skeleton

The article deals with the residential development of the period of Stalinist neoclassicism in the city of Saratov. The method developed by the author for identifying the type of volume-spatial solution of a building is described. Using this method, four types of volumetric-spatial solution of residential buildings of the period of Stalinist neoclassicism are identified. A brief review of the placement in the structure of the city and the identified compositional patterns for all types of residential buildings in the city of Saratov during the period of Stalinist neoclassicism is given.

Keywords: volume-spatial solution, typology of buildings, Stalinist neoclassicism, Soviet development, residential buildings

Cement compositions based on slag-Portland cement containing finely ground slag in its composition are considered. Fine-ground slag was obtained by grinding in a laboratory jet mill equipped with an automatic classifier. The upper limit of slag grinding was 20 microns. It was found that the introduction of 1-3% fine-ground slag into the composition of slag-Portland cement made it possible to increase the strength and structural characteristics of cement stone in the early stages of hardening. To ensure the stabilizing effect of finely ground slag particles in the cement matrix, cement compositions were sealed with water with the addition of a sulfonaphthalene-formaldehyde-based plasticizer in an amount of 0.5% of the cement content. In the course of research, it was found that the strength of samples containing finely ground slag and plasticizer increased by 50% at an early age of hardening (1-3 days), by 30% on average at 28 days of hardening, while the porosity of the samples decreased by 19% and 33%, respectively.

Keywords: fine-ground slag, ultrafine grinding, slag-Portland cement, plasticizer, cement stone, strength, porosity, normal density, setting time, degree of hydration

The article contains statistics on the number of destroyed buildings as a result of emergencies that have occurred over the past twenty years. A table has been formed taking into account the factors of selection of the method of erecting buildings.

Keywords: earthquake, construction technology, factor, selection of construction method

The article deals with issues related to the operation of dedusting systems for technological equipment in the production of gypsum and gypsum building materials. The purpose of the research is to identify the features of the layout and operation modes of aspiration systems operated at existing enterprises. Data on the mass of dust determined from the results of measurements entering the working area from individual technological units are given. According to the results of measurements, it was found that from 10% to 20% of the mass of dust released in the technological process enters the working area. Examples of layout solutions for branched aspiration systems serving conveyors, transfer units, crushers of various types are given. It is shown that the reasons for their unsatisfactory work are the lack of aerodynamic linkage and insufficient volumes of removed air. The features of the layout and operating modes of the aspiration system from the gypsum boiler and mill are described. It is shown that individual sections of the system and the system as a whole operate in non-stationary modes, which is due to the variability of the flow rates and dustiness of the moving dust and gas flows.

Keywords: dustiness, dust emission, aspiration system, aerodynamic coupling, flow rate, concentration, dust and gas mixture

The study findings on the utilization of ethyl silicates for enhancing bitumen properties are showcased. The impact of ethyl silicate grades 28, 32, and 40 on the characteristics of BN 90/10, BN 70/30 construction bitumen, and BND 60/90 road bitumen was evaluated. On the basis of the conducted studies, grades of bitumen and ethyl silicate were selected, the compositions based on which have the best performance. The compatibility of ethyl silicates with bitumen was tested. It has been established that a smaller amount of ethyl silicate is combined with high-quality bitumen. Based on the infra-red spectra, it was shown that there is no chemical interaction between bitumen and ethyl silicate, but a hydrolysis reaction occurs with the formation of hydrogen bonds. It has moreover been determined that ethyl silicates exhibit both plasticizing and structuring effects on bitumen, resulting in improved frost resistance of polymer-bitumen compositions. Requirements for materials aimed at waterproofing of structures for soil and concrete constructions have been developed and presented. In order to increase the low-temperature limit of applicability of polymer bitumen compositions, additives of liquid oligomeric rubbers from the Yaroslavl synthetic rubber plant (SK-1), as well as latexes from the Krasnoyarsk and Omsk plants were studied together with ethyl silicates. Recommendations are given on the use of ethyl silicates in waterproofing mastics and asphalt polymer concrete.

Keywords: bitumen, ethyl silicates, compatibility, properties, plasticizing and structuring additives, waterproofing mastics, asphalt polymer concrete, IR spectra, soil and concrete structures

Currently, due to the growing shortage of basic energy resources, the increase in the cost of their production and the presence of acute problems associated with environmental degradation, the integrated use of energy-saving measures and innovative energy-efficient technologies in the construction industry is one of the necessary conditions for the successful development of the country's national economy and maintaining a favorable environmental conditions.

Keywords: energy saving, resource saving, energy efficient technologies, construction industry, alternative energy sources

On the basis of the study, an analysis was made of the capacity of the roundabout according to the existing traffic intensity in the city, taking into account the composition of the traffic flow, the main factors affecting the passage of vehicles at the entrance to the self-regulated intersection are given. The possibilities of reducing congestion within the framework of the existing street and road network of the city are analyzed, conclusions and recommendations are given based on the results obtained.

Keywords: traffic capacity, traffic composition, roundabout, design speed, vehicle spacing, center island, load level, congestion, normalized traffic volume, number of lanes, service level

Air pollution in urban areas contributes to the development of various diseases among the population. In this connection, its environmental monitoring is relevant. Goals and objectives. The aim of the study was to study the redox potential of aerosols in the residential area of the village. Kuporosny (Volgograd, Sovetsky district) (experimental area) in comparison with the conditionally clean zone. The objectives of the study were to select aerosol particles in the leaves of apricot trees (Prunus armeniaca L.); preparation of aerosol suspensions from the leaves of apricot trees; study of the ORP of aerosol suspensions when they are infused for 5 minutes in distilled water; discussion of the obtained results. Methods. Leaves of apricot trees (Prunus armeniaca L.) in the amount of 10 pcs. placed in a glass dish, added 100 ml. distilled water, stirred them for several minutes with a glass rod to wash the particles from the surface of the leaves. As a result, aerosol suspensions were obtained, in which the ORP was studied. The ORP value was measured using electrochemical equipment (SevenCompact pH meter S220, manufacturer: Mettler-Toledo GmbH, Switzerland). Results. Established air pollution residential area in the village. Vitriol based on low values of the redox potential (Eh=30.03+0.27 (mV)) compared to the conditionally clean zone (Eh=140.83+0.81 (mV)). Conclusion. The results obtained indicate the predominance of recovery processes in the atmosphere of the residential zone of the village. Vitriol, the deterioration of its oxygen regime and the development of environmental risks for the population living there. In this connection, it is required to establish sources of pollution and develop appropriate environmental measures.

Keywords: aerosols, redox potential, environmental monitoring, residential areas, atmospheric air pollution

The relevance of forensic construction and technical expertise in the Russian Federation increases with the increase in the level of urbanization and at the same time the community of forensic construction experts with deep knowledge in the construction field obtained as a result of professional education is growing rapidly. The article raises the issues of lagging the level of preparedness of construction experts in procedural matters, in the skills of mastering the art of polemics, in the ability to flawlessly design the results of the examination in the form of an expert opinion. The authors of the article, based on the study of the practice of conducting judicial construction and technical examinations, analyzed the organizational and legal problems arising from the expert in connection with the violation of the principle of unity of form and content during the examination, underestimating the importance of putting evidence in a strict procedural form.

Keywords: construction and technical forensic examination, special knowledge, forensic expert, examination production, examination procedure

In connection with improvement of public welfare, coming to the fore are requirements enabling comfortable living, which primarily depends on conditions of indoor air environment. This article provides arguments to suggest that, during reconstruction and overhaul of residential buildings, natural ventilation systems, failing to provide the required air exchange, need to be replaced with hybrid ventilation systems, allowing to maintain stable ventilation in existing multi-storey buildings throughout the year and involving minor capital and operating costs. Based on the example of a typical nine-storey residential building, two variations of hybrid ventilation have been developed: containing an ejector and roof fans, with economic feasibility of using both determined.

Keywords: microclimate quality, air exchange, natural ventilation, hybrid ventilation, an ejector, a roof fan, economic feasibility

The article presents the results of theoretical and experimental scientific research on the problem of monitoring the safety of a coal-mining region at the stage of closing unpromising mines. To achieve the goal of research - the formation of an effective methodology for this problem - the following main tasks have been solved: - assessment of the negative impact of mining operations on the technosphere of the region; - selection of the basic characteristics of the natural-technogenic system; - comparative analysis of methods and technical and technological systems for environmental control. The authors of the article formulated the concept of a safe region and the hypothesis of its implementation. In particular, scientific and methodological approaches have been developed that provide an objective assessment of the results of research and the adoption of managerial decisions on the formation of a safe environment for the life of the population. The article shows that the effectiveness of the developed methodology in specific conditions is 85-90%.

Keywords: coal mining region, liquidation of mines, coal rock massif, methodology, natural-technogenic system, safety concept, proactive monitoring

The paper considers an example of solving a plane problem of the theory of plasticity as applied to concrete, which occurs when an absolutely rigid stamp acts on a concrete base. In this case, the solution was sought in the form of isolines of characteristics, the position of which made it possible to determine the stress state of the foundation. In this case, three areas were distinguished, differing in the stressed state. In the work, it was possible to analyze the effect of friction on the surface of the stamp on the boundaries of these regions and the isolines of stresses in them. Three conditions were considered: friction is absent, friction is constant, friction is proportional to the greater principal stress. The influence of various boundary conditions on the surface of the stamp on the stress state of the concrete base is revealed.

Keywords: concrete, theory of plasticity, plane problem, stress-strain state, stresses, friction, corner punch

The development of modern cities, caused by the need to improve the living environment, contributes to the creation of new buildings and structures. As a result, the density of typical urban development increases, mainly with rectangular buildings. Such buildings, with closed areas of courtyard spaces, create extreme microclimatic conditions and aggravate the air exchange of territories, thereby violating thermal and environmental comfort. This situation is especially acute in the southern cities. The article analyzes the influence of modern typical building on the microclimatic conditions of yard spaces. The factors influencing the formation of the heat and wind regime of urban areas have been identified. On the example of a building with a characteristic orientation for the conditions of Dushanbe, a graphical-analytical calculation of the duration of facade insolation was carried out. The role of insolation in the formation of convective flows of thermal origin is determined. On the basis of field studies, changes in the maximum speed of convective flows near the walls of the building were determined. The role of convective flows of thermal origin in the formation of the heat-wind regime of yard spaces is indicated.

Keywords: spherical buildings, ecology, energy consumption, energy efficiency, heat loss, air exchange, environment, enclosing structures

The possibility and expediency of switching from qualitative regulation of heat supply to quantitative in centralized heat supply systems for the existing network from the district boiler house No. 1364 of Volgograd is substantiated. The main advantages and disadvantages of each method of regulating heat supply to consumers are considered. The basic formulas for determining the thermal loads required depending on the outside air temperature, the hydraulic calibration calculation of the existing network from boiler house No. 1364 are described. Volgograd, determination of the internal hydraulic characteristics of the resistance of the heat network and determination of the required hydraulic regime for consumers of the microdistrict No. 1364, depending on the change in coolant flow due to the regulation of the speed of rotation of the pump impeller. As a result, the implementation of the transition from a qualitative to a quantitative method of regulating heat release is possible without serious hydraulic interventions.

Keywords: heat supply, control methods, heat carrier temperature, heat carrier consumption, boiler room, heat network, pump, frequency-controlled drive, hydraulic modes, thermal energy saving

At the beginning of 1908, the Tsarskoye Selo Community of the Sisters of Mercy of the Red Cross was organized in the city, which was allocated a plot for the construction of a building for an outpatient clinic and a dormitory of the sisters of mercy with a church. The development of the project and supervision of the construction was carried out by architect S.A. Danini. Construction of the building was started in 1912 and completed in October 1914. The internal load-bearing structures of the building were made of monolithic reinforced concrete, central water heating and ventilation system were used. Building survey in 2017-2019 it has shown that it is possible to reconstruct it for a day-stay boarding house for disabled children.

Keywords: Tsarskoye Selo, S.A. Danini, Community of the Sisters of Mercy of the Red Cross, architectural planning solutions, reinforced concrete structures, building surveys, church in honor of the Icon of the Mother of God of All Sorrowing Joy

One of the methods for strengthening connections in steel trusses made of cold-formed welded profiles is the use of plate overlays. This article presents their influence on increasing the strength of connections according to the criterion of bearing capacity under compression. The investigations were conducted using the component finite element method. The obtained dependencies of the increase in bearing capacity are demonstrated based on the width and angle of the brace connection. An engineering methodology has been developed to assess the strength of the reinforced connection under compression, utilizing a traditional formula from Russian design standards with the substitution of the thickness of the chord by the equivalent thickness.

Keywords: : reinforcement, connections, cold-formed profiles, bearing capacity, compression

There are a lot of monolithic and precast-monolithic reinforced concrete structures in construction. The relevance of the issue of ensuring reliable contact of concrete in the seams and joints in the contact zone of newly laid (""new"") concrete with already gained a certain strength (""old"") concrete is increasing. In the work, the influence of the pH of the medium on the adhesion strength of ""new"" and ""old"" concrete, which occurs when making joints in prefabricated monolithic structures and organizing technological seams of concreting in monolithic construction, was considered. Standard methods were used. Experimental data have been obtained that indicate the influence of the pH of the ""new"" medium on the adhesion strength of the ""new"" concrete with the base of the ""old"" concrete. The analysis and comparison of the received results with the data of the researches conducted earlier is carried out. Recommendations are formulated to improve the strength of concrete contact in seams and joints during the construction of monolithic and precast-monolithic reinforced concrete structures.

Keywords: new-to-old concrete bonding, technological concreting joint, monolithic reinforced concrete structures, precast-monolithic reinforced concrete structures

A review of the literature in the field of construction heat engineering and regulatory requirements for thermal protection of buildings is given. A study of methods of increasing thermal protection for reconstructed and designed buildings, taking into account modern requirements, has been carried out. A methodology for strengthening the thermal protection of building structures has been developed.

Keywords: thermal performance of building , energy efficiency, heat-efficient enclosing structures, thermal insulation materials

The expediency of using a finely ground mineral additive from burnt mudstone clay for the production of heat-resistant expanded clay concrete based on Portland cement with a rational dose of the additive of 30...50% by weight of the binder is shown. Compositions of heat-resistant expanded clay concrete with a maximum permissible application temperature of I10 classes in compressive strength up to B15 and an average density of up to 1500 kg/m3 have been developed. The efficiency of the technology for obtaining heat-resistant expanded clay concrete using pre-forced electric heating of the concrete mixture up to 60°C is substantiated and rational technological parameters of electric heating are determined. The residual strength of heat-resistant expanded clay concrete obtained using the developed technology, after short-term heating to 1000oC, exceeds 0.65 of the initial, which is higher than the values for analogues according to SP 27.13330.2017. The coefficient of linear temperature expansion of the developed heat-resistant expanded clay concrete in the temperature range of 200...1000oC varies within 2 ...5,8ˑ10-6 1/oC. The increase in the coefficient of thermal conductivity of the studied concretes with an increase in temperature up to 1000°C is up to 34%. The heat resistance of heat-resistant expanded clay concrete at 800oC, obtained using the technology of pre-forced electric heating of the mixture, was 12, 14 and 15 air heat changes, respectively, at a temperature of pre-forced electric heating of 60, 80 and 90 оC.

Keywords: heat-resistant expanded clay concrete, fine-ground mineral additive, mudstone, thermal conductivity coefficient, coefficient of linear thermal expansion, residual strength