The article considers the problem of sediment formation, sludge and corrosion on the heat transfer surface during the operation of heat exchange equipment at housing and communal services facilities. A new method of non-selective mechanical cleaning using a water hammer is proposed. The description and principle of operation of this cleaning system at the central heating station of the Ogarev Moscow State University are given. To confirm the effectiveness of the proposed technical solution, the results of thermal and hydraulic tests are presented.
Keywords: deposits, sludge, corrosion, cleaning, heat exchanger, water hammer, heat transfer
As part of the work on the PhD thesis on the creation of new systems and calculation devices for the design of reinforced concrete tanks for the storage of liquefied natural gas, work was done to determine the properties of concrete mixtures used in the construction of tanks in Vietnam, namely in the Hanoi area. A feature of the materials used for the manufacture of concrete is the use of local rocks, which have distinctive properties, which affects the strength and deformation properties of concrete. The article presents the results of experimental studies of the properties of concretes made with Vietnamese materials. A relationship was established between the modulus of elasticity of concrete and its prismatic compressive strength. As part of the study, 16 formulas of concrete mixtures on different materials from Vietnam were compiled and studied. As a result of the conducted research, the dependence of the modulus of elasticity and the intended strength of concrete was revealed, which will later be used in the creation of calculation devices for the design of reinforced concrete structures.
Keywords: concrete, reinforced concrete, materials, structures, modulus of elasticity, prismatic strength of concrete, deformations
This article discusses the main factors leading to a decrease in the bearing capacity of the support bases and the possible loss of stability of the offshore platform, which will entail emergency consequences. The impact of free gas in the upper sections of the soil and dynamic external loads on the safety of construction and operation of oil platforms has been assessed. Calculations for the bearing capacity of the pile foundation of the support bases of the SPBU Astra in the Caspian Sea, performed according to existing methods, were analyzed. The determination of the strength of the soil is carried out for the calculated support surface – the section of the column having the maximum area.
Keywords: geodynamic effects, bearing capacity, pile foundation, indentation depth, free gas
The results of a study of the influence of shrinkage deformations on the basic physical and mechanical properties of concrete are presented depending on various production and technological factors. The research methodology took into account the choice of the period of aging concrete in a dry, hot climate to study the influence of physical processes in concrete on its physical and mechanical properties. The influence of shrinkage deformations on the strength characteristics of concrete was studied. an increase in the intensity of mass transfer processes between concrete and the environment leads to an increase in destructive shrinkage deformations, mainly plastic shrinkage of concrete, which lead to changes in the structure and physical and mechanical properties of mature concrete. The consistency of the concrete mixture also influences the amount of strength reduction. with a greater value of plastic shrinkage of concrete, its compressive and tensile strength in bending decreases. the destructive effect of plastic shrinkage on concrete caused depends on a number of technological factors (consistency of the concrete mixture, w/c, temperature and humidity hardening conditions, etc.).
Keywords: curing period, mass transfer processes, plastic shrinkage, concrete structure, concrete strength, reconstruction, buildings and structures
The article examines the application of properties of polyethyleneimine (PEI) and polyacrylic acid (PAK) polycomplex composition for soil strengthening. During the studies, the ratio of PEI and PAA (by dry weight) was established, at which the reagents most fully enter the complexation reaction. The polycomplex composition of the optimal composition was used to strengthen the soils of some varieties. When studying the properties of hardened soils, dependencies were obtained: the ultimate strength of the hardened soil on the relative humidity and the thickness of the layer of hardened soil on the consumption of complexing reagents. The paper concluded that the use of polycomplexes for soil strengthening is promising.
Keywords: polycomplex composition, soil strengthening, polyethyleneimine, polyacrylic acid, impregnation method, dedusting, optimal humidity
The construction industry is undergoing regular changes these days, influenced by many different factors. Large and structurally complex construction projects reveal more and more imperfections in traditional construction methods, e.g. increased time or production costs, downtime, delays, etc. Lean construction and its principles have emerged in search of solutions to problems in construction. In the search for solutions to problems in construction, the term - lean construction and its principles appeared, which replaced traditional methods and aimed at finding new approaches in the implementation of construction activities. In this scientific article the definition of Lean Construction is given, and also the history of Lean Construction and its chronology are considered. The comparison of the traditional construction model and Lean model is given, and also the connection of Building Information Modeling (BIM) with Lean Construction principles is analysed and an example of this connection is given.
Keywords: lean manufacturing, lean construction, construction, lean construction principles, lean technology, lean model, lean philosophy, life cycle of an object, information modelling technologies, engineering
An important condition for the high-quality development of the construction industry is the further increase in energy efficiency and environmental friendliness of design solutions in the field of roof enclosing structures. Therefore, solving the problem of correctly choosing the most effective roof instalation to increase the life cycle of the entire building becomes more relevant. The widespread use of a wide variety of both traditional and more durable and reliable roofing coverings in modern construction practice makes it difficult to choose the most effective option. The article develops a methodology for choosing an effective roof instalation option based on the use of economic and mathematical tools, based on the analysis of organizational and technological calculations and technical and economic comparison of various options
Keywords: additive optimality criterion, roofing, roofing covering, operation, methodology, organizational and technological calculations, rational technology, roof tiles, operating costs, efficiency, economic and mathematical modeling
The purpose of this paper is to examine the architectural and planning strategies used by universities to expand their campuses to accommodate growing student numbers. It provides a comprehensive analysis of four case studies that highlight successful methods used by universities to expand their campuses. The article focuses on analyzing the practical experience of three types of expansion strategies for existing campuses: vertical campus expansion, underground campus expansion, and horizontal campus expansion. Campus expansion strategies were discussed in terms of advantages and disadvantages and a comparative analysis was carried out. Lessons learned from each strategy have been drawn to benefit and offer solutions to other regions whose universities are suffering from the challenge of increasing university enrollment.
Keywords: urban planning, higher education facilities, vertical development, underground development, horizontal development, university enrollment
The capture and disposal of harmful emissions is an urgent task of our time. This article describes various methods of improving the environmental friendliness of industrial enterprises by cleaning flue gases. The most promising purification technology is adsorption. Therefore, the paper presents laboratory studies of the testing of some adsorption materials for the efficiency of carbon dioxide capture. The key formulas of sorption purification methods are displayed, and the results are presented. Based on experimental studies, an adsorption material was selected that has a potentially high absorption efficiency after activation and refinement of a composition that can be regenerated.
Keywords: flue gases, adsorption, absorption, carbon dioxide, greenhouse effect, sorption materials, absorption efficiency
This article analyzes trends and examples of the use of digital technology in order to increase the efficiency and improve the quality of construction projects. BIM technologies already at the design stage make it possible to provide as much as possible all the signs that affect the construction object at the beginning of construction and its further operation. The number of these signs increases, due to the fact that the complexity of the construction process of construction objects increases, as the scale of construction increases, the volume of construction products and building materials increases. In this connection, the requirements for the general designer, contractor, customer, etc. are increasing. At the same time, the customer expects to find, in addition to the project, a solution to reduce costs and increase the functionality of the construction object with the highest parameters. The need for high-performance special technologies and methods of organizing the management of construction works is becoming more acute. BIM technologies are the physical and functional characteristics of a construction object presented in digital form. Digital technologies are an integrated special resource of competencies in order to obtain information about a construction object. It provides the basis for the possibility to accept special decisions of a construction object from construction to the moment of its demolition. This model provides an opportunity to delegate a virtual digital model from the creators of the project to the subcontractor, general contractor, owner, as well as the manager of the construction object. The technical tasks of using information modeling technologies are the starting point for planning an investment project both from the customer's position, since they define the scope of using a BIM model at all phases of the operation of a construction object according to the criteria for evaluating information, and from the position of the contractor, since it acts as the basis for generating a plan when a BIM project will be implemented. The list of characteristic technical tasks of BIM modeling application at different stages of the construction object life cycle is determined. The BIM project algorithm is proposed.
Keywords: information modeling of the construction of objects, labor productivity, physical wear, defects, reliability, diagnostic tasks
Industrial enterprises place high demands on the quality of demineralized water, the economic feasibility of this process, as well as its environmental friendliness. The water treatment plant begins with pre-treatment, which allows the removal of dissolved suspensions, mechanical impurities and organic substances. Most often, the pre-cleaning process is organized using clarifiers. The type of clarifier used significantly affects both the efficiency of the process and its economic characteristics. The paper presents a comparative characteristic of the operation of vertical cylindrical clarifiers of the Central Research Institute, VTI and high-speed clarifiers with a pulsating column. The main operational characteristics are highlighted, and the cost of clarified water is calculated when using different types of clarifiers.
Keywords: clarifier, pre-cleaning, cleaning quality indicators, thermal power plants
The article presents a way to increase the load-bearing capacity of a reinforced concrete column due to metal clips from the corners with an increase in the load on it. To ensure the joint operation of the existing column and the metal cage, the corners are subjected to prestressing, which is achieved by compressing the corners with jacks.
Keywords: reinforced concrete column, column reinforcement, metal cage, prestressing of the cage
Concrete paving slabs for road construction are made from mixtures consisting of hydraulic binder, fine and coarse aggregates and water. The prepared mixture of a given humidity is subjected to vibration molding under the following technological conditions: process duration 5–10 seconds, vibration frequency 30–50 Hz and pressure 70–80 kg/cm2. Hardening of freshly molded samples is carried out in a heat and humidity treatment chamber. It has been established that it is possible to replace natural coarse aggregate with fractionated scrap concrete. The compressive strength of concrete with aggregate based on recycled crushed stone is 300 - 400 kg/cm2, water absorption 4.8 - 6.2%, frost resistance F2 200 - 300. The proposed technology allows solving both economic and environmental issues for regions with large amounts of concrete scrap at temporary industrial waste storage sites.
Keywords: concrete mixture, vibroforming, modifiers, filler, waste, concrete scrap, strength
The functional and spatial aspects of the formation of the architectural environment of medical rehabilitation and rehabilitation centers for injured athletes are investigated. The theoretical basis on the problems of functioning of similar facilities - rehabilitation centers for the disabled is considered, the characteristic components of the environment are identified, as well as the technological stages of the rehabilitation process. The generalization of the best Russian experience and existing architectural and planning solutions of medical institutions with rehabilitation functions is carried out. A comparative analysis of analog facilities was carried out in three conditional groups: a) large medical centers with rehabilitation functions for the disabled; b) multidisciplinary rehabilitation centers; c) specialized rehabilitation centers for athletes. A number of promising approaches and trends are identified that can be applied to the formation of conceptual models and adaptive architectural and environmental solutions for sports medicine and rehabilitation centers.
Keywords: rehabilitation center for athletes, functional-spatial, architectural-planning, environmental solutions, models, approaches
Performance of construction and installation works in the conditions of existing health care facilities requires participants of the construction industry to take into account technical equipment of facilities, their specifics, influence of various factors and external conditions on the organisation of construction production, architectural and design solutions of facilities, preservatThe performance of construction and installation works in the conditions of existing healthcare institutions requires from the participants of construction production to take into account the technical equipment of facilities, their specifics, the impact on the organisation of construction production of various factors and external conditions, architectural and planning solutions of facilities, preservation of the functionality of medical institutions and the possibility of their current operation. This article raises the question of searching for new or existing techniques in organisational and technological design, which help to increase the validity of organisational and technological solutions. The practice of reconstruction of medical institutions in modern construction production does not take into account enough factors influencing the development of architectural and planning solutions. However, it is these factors that are determined at the stage of formation of medical and technological task. Such insufficient attention to the factors can significantly affect the organisation of the construction process. The article considers the experience and peculiarities of the organisation of construction production in the reconstruction of healthcare facilities, reflected in the works of domestic and foreign scientists and researchers.
Keywords: reconstruction, healthcare facilities, organizational and technological solutions, documentation, workspace, time, labor costs, transactional model, productivity
The presence of a large number of undeveloped areas within the city - now inactive enterprises - creates a negative impact on the urban environment. Since these territories are depressed spaces, the design of new residential areas with characteristic high-rise buildings seems to be a logical path for the development of the city. However, uncontrolled urbanization and dense multi-storey buildings represent a fundamental change in the human environment. The consequences of this approach lead to a deterioration in the air exchange of areas and contributes to the formation of “heat islands” that affect air pollution. This contributes to the deterioration of the environmental and social situation and the emergence of a negative perception of the environment among the population. The worsening of this problem may cause a deterioration in the social climate in large cities. The article analyzes the impact of dense high-rise buildings on the environment located on the territory of non-operating enterprises. Methods for solving this problem are indicated. The results of field observations and studies of the interhouse space are presented, on the basis of which the role of convective flows of thermal origin in the air exchange of urban space is revealed. A comparative analysis of projects for the development of the territory of a former house-building plant with complexes for various functional purposes is presented.
Keywords: urban area, air exchange, convective flows, temperature conditions, standard buildings, renovation, leisure facilities, depressed spaces
The practical significance associated with the development of automated software systems for calculating joints of steel structures of buildings and structures is noted. Using the IDEA Statica software package as an example, the calculation and analysis of the operation of a steel unit connecting the lower chord of a truss to a column was carried out. The order and sequence of entering the initial data for calculating the connection is shown. The calculation results present in tabular and graphical forms the equivalent stresses and plastic deformations of the main elements, as well as the results of inspections of bolted and welded connections of these elements to each other. A comparative analysis of numerical and analytical calculations was performed. Conclusions are formulated based on the results presented in the article.
Keywords: calculation model, connections, steel structures, component finite element method, design, nonlinear analysis, work analysis, stress, plastic deformation, bolted connection, welded connection
The article considers ecological and landscape features on the example of modern realized objects of wine tourism in the South of Russia. Based on the analysis of a number of new winery facilities and publications on this issue, some features in the context of modern architecture and its enotourism component are identified. Conclusions are made about the conformity of these features to the global modern trends in the design of buildings, such as environmental friendliness and resource conservation, respect for the landscape. On the example of the considered objects the hypothesis that the techniques of architect's work with the environment in conjunction with the original architecture increase the tourist attractiveness of wine production in general is confirmed.
Keywords: architecture, winery, enotourism, agritourism, landscape, project, landscaping, volume and planning solutions
The cases of uneven compression of a concrete cylinder in the case of simple loading and comprehensive uneven compression of a spiral-reinforced concrete cylinder under disproportionate loading are considered. The dependences of longitudinal, transverse and volumetric deformations on longitudinal stress are obtained.
Keywords: longitudinal stress, circumferential stress, longitudinal deformation, circumferential deformation, spiral reinforced concrete strut, shear strain intensity, shear stress intensity
The main means of seismic protection for increasing the seismic resistance of buildings and structures are described. The main problems associated with the design of special seismic protection equipment are outlined. The basic requirements for the design and calculations of steel frame frames taking into account seismic impact in accordance with the current design standards in the Russian Federation are analyzed. There is an insufficient description of the requirements specified in the standards for performing calculations and design of structures and their connections. Recommendations and instructions are given for taking into account the requirements of the standards for the design of steel frame frames. Schematic diagrams of special units for coupling columns with crossbars, necessary for design in seismically hazardous areas, are presented. Conclusions are formulated.
Keywords: special units, columns, beams, seismic impact, seismic protection, steel frames, plastic hinges, excess strength factor, forces, plastic moment, design.
A technological scheme for the production of biostable materials based on monoethanol-modified (N→B)-trihydroxyborate (MEATHB) stems of Sosnovsky's borer and polyurethane binder has been developed. This technological scheme differs from the traditional one in that it includes the process of plant raw material modification to ensure its biostability. The paper presents the results of determining the thermophysical properties of the obtained thermal insulation boards, as well as the results of assessing their biostability. The obtained results correspond to the current requirements for thermal insulation materials. The paper analyzes the main stages and processes necessary to create a high-quality and environmentally friendly product. The main types of plant raw materials used in the production of thermal insulation materials are considered, as well as the features of technological processes associated with its processing and formation. In addition, the advantages of using plant materials in the production of thermal insulation materials from the point of view of ecology are presented.
Keywords: technological scheme, biostable composites, Sosnovsky's borer, modification, biostability, monoethanolamino(N→B)-trihydroxyborate, heat-insulating material
The effect of organomodified silica particles on the extraction of dissolved diesel fuel from water was studied. The dependence of the efficiency of water purification on the concentration and type of solid particles, as well as the concentration and type of surfactant, is shown. When using a short-chain surfactant to modify the surface of silica particles, the minimum residual concentration of diesel fuel was 2.71 mg/l at a concentration of 4% Aerosil-380 and hexylamine 57 mmol/l. Replacing the short-chain surfactant hexylamine with the long-chain CTAMB led to an 8% improvement in the quality of water purification due to an increase in the surface activity of the organic cation. The use of modified clay particles to purify water from diesel fuel showed lower efficiency compared to Aerosil-380 particles at similar concentrations of the solid phase and surfactant modifier.
Keywords: Pickering foam, foam emulsion, diesel fuel, water purification, silica, cationic surfactant, hexylamine, cetyltrimethylammonium bromide
The article considers the possibility of using methods of integrated development of the territory in order to solve the problems of dilapidated and dilapidated housing in large cities of the Moscow region on the example of the city of Sergiev Posad.
Keywords: integrated development of the territory, residential areas, dilapidated and dilapidated housing, large cities, Sergiev Posad
The paper presents a solution to the problem of accelerating the process of visualizing the results of numerical simulation. The volumes of such data can be very large and the development of tools to speed up the process of analyzing modeling results is an urgent task. This article proposes a solution to the problem based on the development of a set of programs that automate the process of processing large-volume scientific data of the same type to create high-quality visualizations of the results of numerical modeling. The results are presented using the example of solving problems in astrophysics, but the proposed methodology can be quite easily applied to other subject areas in which models based on the dynamics of particle systems are used. The research described in the work is devoted to solving issues related to converting data obtained from numerical modeling into a format that can be read by the ParaView softwart, which implements many methods that allow obtaining very high-quality visualization. The work also describes the process of automating batch processing of a large amount of data that has the same structure, presents the results of an analysis of the acceleration of the visualization process when using the NVIDIA IndeX plug-in, and considers the possibility of improving the quality of visualization results when applying Delaunay triangulation to the original data.
Keywords: data visualization, Delaunay triangulation, rendering acceleration, ParaView, NVIDIA IndeX, VTK
Reducing the loss of thermal energy in heating systems and increasing their reliability is an urgent task for the thermal power industry. The use of polyurethane foam insulation of pipelines is currently considered as the most promising solution to this problem. However, the construction of a durable and economical pipeline with PU insulation requires certain conditions. Despite the advantages of using PU insulation, the experience of implementing such pipelines has revealed problems arising from emergency situations that directly affect the reduction of energy efficiency. To solve these problems, an operational remote control system is being introduced to eliminate accidents and monitor insulation moisture. The paper presents an analysis of the implementation of LoRaWAN-based SDCs on heating networks in the Republic of Tatarstan. The study shows that in the first year of operation, the number of defects was higher due to the establishment of an information collection system and the installation of sensors. However, the second year of the experiment demonstrated a decrease in the number of defects and accidents, which indicates an increase in the efficiency of the system. It is recommended to introduce pipelines with PU insulation and SOD to increase the reliability and efficiency of heating networks.
Keywords: pipelines, heating networks, polyurethane foam insulation, reliability, durability, energy efficiency, operational remote control system