The main problem in the strength study of adhesive joints between concrete and carbon fiber on epoxy adhesives is that in most cases the destruction occurs by the separation of concrete. Thus, it is not the strength of the adhesive layer itself that is being investigated, but the strength of concrete for separation. To study the durability of such joints, it is advisable to study their creep. The purpose of this work is to determine the most suitable type of sample for the creep test of an adhesive joint. The objectives of the study are: the development of types of samples with different configurations of adhesive joints, the determination of the samples strength, the study of the samples behavior under the influence of a constant creep load. Results. The results of the study showed that adhesive joints on samples with relatively small adhesive areas have a rather high rigidity in relation to the concrete substrate itself. The strength of the concrete part lags far behind the strength of the adhesive and carbon fiber itself. The rate of creep development on such samples is extremely low. Conclusions. The deformability of samples with a relatively small adhesive area does not allow their use to predict creep, since the rate of deformation development on these samples is extremely low, and the effect of temperature exposure is not significant. To study creep, the most suitable type of samples is a structurally similar sample – a reinforced concrete beam reinforced with an external reinforcement system made of carbon fiber.

Prefabricated monolithic housing construction in Russia and other countries has been actively developing in recent years. There is a constant increase in the volume of construction from precast-monolithic reinforced concrete. Along with this, the features of the deformation process of prefabricated monolithic buildings that arise during installation have not been sufficiently studied. The purpose of experimental research is to study the peculiarities of the formation of the stress–strain state of a flat frame of a prefabricated monolithic framework, taking into account the phased installation and loading. The objectives of the study are: development of a methodology for conducting an experiment of step-by-step installation and loading of a prefabricated monolithic frame; conducting an experiment; analyzing the results obtained. Results. Experimental studies of a prefabricated monolithic flat frame took into account the stages of installation and loading. The first stage is the installation of prefabricated elements (columns, prefabricated parts of crossbars) and their subsequent loading with a load simulating the weight of monolithic concrete and supported elements. The second stage (the load of the first stage is not removed) is laying of monolithic concrete, the set of the required strength and inclusion in the deformation process, the application of an additional load modeling the weight of floor structures, partitions, curtain walls and operational load. As a result of the conducted research, the features of the formation of the stress-strain state of the prefabricated monolithic frame are determined. A change in the nature of the formation of the stress-strain state of the frame of a prefabricated monolithic building after laying monolithic concrete and involving it in the deformation process has been revealed. Conclusions. The conducted experimental studies indicate that the process of installation and step-by-step involvement in the deformation process of both individual elements (columns, crossbars) of the prefabricated monolithic frame and the components of these elements (prefabricated and monolithic parts of the crossbar) determines the nature of the formation of stress-strain of the prefabricated monolithic frame.

The main problem in the construction of steel polygonal arches is the design of a reliable nodal connection, both from the point of view of ensuring load-bearing capacity and reducing steel consumption, while the nodal connection must provide the required outline of the arch. The purpose of the work is to develop a nodal connection of standardized elements without flanges, allowing the construction of an arch of arbitrary span and comparison of the design solution in terms of steel consumption with known analogues. The objectives of the study are: consideration of known nodal connections of steel polygonal arches, identification of advantages and disadvantages, development of a new connection and comparison of steel consumption and manufacturing complexity with existing technical solutions. Results. The paper presents the results of studies of nodal connections of steel polygonal arches. As a result, it was revealed that the polygonal arch proposed in this work has the lowest cost in terms of steel consumption: its cost is 7.7% less than the cost of an arch with ring inserts and 19.3% less than the cost of an arch made of the same type of elements. Conclusions. The significance of the results obtained for the construction industry is that due to the direct connection of the standardized elements of polygonal arches, the need for flanges is eliminated, which makes it possible to lighten the load-bearing structure.

According to Federal Law No. 384 “Technical Regulations on the Safety of Buildings and Structures,” buildings are subject to noise protection requirements, which are implemented by meeting the requirements of SP 51.13330 “Noise Protection.” In this case, noise sources are traditionally transport noise, equipment noise and other sources, which position in space is known at the calculation stage. Characteristics of noise arising in structures as a result of deformation, vibration, friction, etc. are often not defined. The problem of localizing structural noise in architectural and construction practice is not sufficiently covered. There are known methods for localizing a point source of noise based on measuring the signal delay between microphones (triangulation, trilateration, etc.), however, the practical implementation of such systems can be very labor-intensive and expensive. At the same time, the use of these methods can be complicated by the fact that structural noise can differ from point noise since it can spread along extended structural elements. In view of the above problems, the purpose of the study is to develop and test a method for localizing the source of structural noise under operating conditions. The main objectives of the study are formulated in the following way. Research objectives: 1. Development of a prototype of the system for monitoring, recording and localizing the source of structural noise; 2. Development of a noise localization method based on digitization and analysis of audio signal recordings; 3. Testing of the developed method in natural operating conditions of buildings. Results. The results of a study of noise monitoring under natural operating conditions of a building are presented based on the developed prototype of the system for recording and localizing the source of structural noise. A noise localization method has been developed based on digitization and analysis of the sound signal recording by volume. The advantages and disadvantages of using the method of localizing a noise source by volume level are formulated. Conclusions. An alternative method for localizing a noise source in architectural and construction practice is proposed, the main difference of which is the principle of determining the position of a noise source by volume level. The significance of the results obtained for the construction industry lies in the significant reduction in cost and ease of implementation of the noise source localization system.

When reinforcing reinforced concrete structures with an external reinforcement system made of carbon fiber, epoxy adhesives are mainly used. The component of these systems that is most susceptible to the effects of operational factors is precisely the epoxy adhesive. To study the durability of structures reinforced with NEA, it is necessary to study the stress-strain state of the contact layer. The purpose of this work is to study a numerical model of the stress-strain state of a reinforced concrete beam reinforced with carbon fiber. Research objectives: development of a finite element model, reinforced concrete beam reinforced with carbon fiber; calculation and analysis of the results. Results. According to the results of calculations, it can be seen that concrete deformations and carbon fiber deformations are very different. Deformations on concrete are significantly greater than deformations on carbon fiber. This development of deformations indicates a displacement in the zone of the contact layer between concrete and carbon fiber. Conclusions. Finite element modeling of a reinforced concrete beam reinforced with an external reinforcement system has been carried out. As a result of the selection of various models, it was possible to develop the most suitable computational model with good convergence of the results with experimental data.

When designing foundation base, the question arises about the mechanical characteristics of soils used in limit state calculations, especially if cyclic loading is considered as an external influence. At the same time, the “time” factor is not taken into account, that the structure is being built and operated for a long period. One of the ways to solve this issue can be to study the change in soil properties over time. The main purpose of this study is to identify the features of the change in the strength of clay soil samples under conditions of triaxial cyclic loading at different values of the exposure time in the desiccator before and during loading. The objectives of the study are to identify graphical dependencies and patterns of changes in soil strength over time and substantiate the results obtained. Results. Experimental studies were carried out on cylindrical samples made from soil of a disturbed structure. The main results of the studies performed are new data on the change in the strength of samples under triaxial loading depending on the loading mode, taking into account the time of "hold before testing" and "rest during testing". The analysis of the research results is carried out and some regularities of the behavior of clay soils under regime triaxial loading are established. Conclusions. Establishing the influence of time on the change in the values of limiting vertical stresses in a sample of clay soil of a disturbed structure under conditions of triaxial compression is an important task in the construction industry.

In modern construction, the use of underground space becomes an integral part of projects in densely populated cities. The aim of the study is to determine the prospects of development and trends for improving the design and construction of underground structures in the conditions of urban development. The objectives of the study are to analyze the works of Russian and foreign authors aimed at studying underground structures with the use of "diaphragm wall". Results. In the course of research review it was revealed that the most popular way of excavation enclosure execution in conditions of dense urban development is "diaphragm wall". The main trends of research were defined: analysis of the behavior of excavation enclosure structures, possibility of digitalization and automation of selection of design solutions for underground part of buildings, calculation and monitoring of underground load-bearing structures of the building, selection of excavation enclosure and retention system. Conclusions. Due to the done research, the modern tendencies in development of design and construction of underground structures with application of "diaphragm wall" have been established and topical problems have been revealed, which determines directions for formation of further researches.

The relevance of the research lies in several provisions: the period of activity of the provincial architect Foma Ivanovich Petondi is insufficiently studied, the context of the implementation of architectural and urban planning activities in the Kazan province of the first half of ХIХ century is not revealed. The purpose of this work is to establish the principles of the organization and implementation of architectural activities of provincial architects of the specified period, as well as to identify the personal contribution of Foma Ivanovich Petondi to the architectural activities of the Construction Committee of Kazan province, as an urban planner, representative of architectural supervision and a manager. The objectives of the study include a bibliographic analysis of the activities of the provincial architect Petondi, the study of the principles of the structure and implementation of the architectural activities of the provincial architects of the specified period, the identification of the features of the functions of the provincial architect in the role of a manager and an urban planner. Results. According to the results of the study, it was revealed that Petondi was the first provincial architect who acted in accordance with the first edition of the Building Charter and conducted full-fledged urban planning activities in the Kazan province. It is proved that the provincial architect performs the role of architectural supervision, land management and official interaction of the architect with police units and fire department. Prerequisites for the inclusion of changes in the regular city plan are established, and assumptions are made about the revision of the scale of the changes made by Petondi to the regular structure of the city. Conclusions. The significance of the work carried out lies in identifying the features of the architectural activities of the provincial architect, as well as in establishing the real boundaries of the regular plan of Kazan, developed by Petondi in 1838. The materials of this research will help to study the architecture of Kazan deeper and establish the real contribution of Petondi to the development of the city.

This article explores typological examples of historical residential buildings located in the coastal zone of the city of Samsun in the northern provinces of Turkey. The study is based on the architectural, planning, and design characteristics of these houses, considering their historical and socio-cultural context. The article highlights the unique architectural details, the use of wood material, and the influence of natural and climatic conditions on the formation of these houses. The purpose of the work. Based on the architectural, planning, and design features of these houses, the article aims to identify the influence of historical, sociocultural, and natural factors on the formation of architectural traditions in the residential construction of this region. The objectives of the study are reviewing the ancient history of Samsun Province, including its geographical location, population, natural conditions, and cultural heritage. Special attention is given to various types of residential buildings, such as village, semi-urban, and manor-palace houses, which reflect social differences and class divisions within society. The study allows for a deeper understanding of the historical and cultural significance of residential construction in this region. Results. The study identified several types of residential buildings typical of the coastal area of the city of Samsun in the northern provinces of Turkey. The architectural solutions in these houses reflect the variety of historical, social, and cultural factors, including natural and climatic conditions, the social status of the population, and trade and applied crafts. Conclusions. Overall, the article provides an overview of the typological features of the historical residential buildings in the city of Samsun, tracing the influence of historical, sociocultural, and natural factors on their formation. The study is important for understanding the architectural heritage and cultural identity of this region of Turkey.

The relevance of the study is due to the fact that stone building structures in historical places represent one of the fundamental elements of architectural buildings and structures. These objects are often unique monuments of architecture and cultural heritage, reflecting historical periods and technologies of past eras. The aim of the study is to analyze modern methods and techniques of masonry restoration, compare and evaluate them, and identify optimal solutions for restoring and preserving the appearance of historic buildings. The objectives of the study are to review modern methods and techniques of restoration of the facades of historic masonry buildings, including analysis of existing restoration approaches and assessment of their effectiveness; to analyze the best known restoration methods and techniques, taking into account the physical and mechanical characteristics of the considered types of building materials; to propose recommendations for the protection and restoration of damaged masonry facades of cultural heritage objects, taking into account the current regulatory requirements and standards. Results. The main result of the study is the development of an integrated approach to the restoration and rehabilitation of damaged facades of historic stone buildings. Conclusions. The significance of the findings for architects and project designers is that they provide specific and science-based recommendations that will help preserve and restore historic masonry buildings while respecting their unique characteristics and meeting modern standards of sustainability and durability.

In modern conditions of high mobility and increasing competition for human capital, the semantic identity of urban areas becomes an integral criterion of a modern comfortable urban environment. The purpose of the study is to develop a semantic approach to the design of open urban public spaces in residential areas. The tasks include determining the main material and non-material components of the urban environment that form its semantic (meaningful) characteristics, developing a methodology for semantic coding of the urban environment and its planning elements. Results. The basic concepts related to the semantic coding of open urban public spaces are formulated, including “semantics of public spaces”, “semantic code of urban public spaces”. The methodology of semantic coding of urban open public spaces has been formed. The projects for the improvement of open urban public spaces of city and district significance in Kazan and Naberezhnye Chelny were developed. Conclusions. The method of semantic coding of open urban public spaces has been developed, which makes it possible to design public spaces having a high degree of “imaginability” and forming the image of the surrounding area.

After the collapse of the Soviet Union, with the end of persecution of religion, an active process of construction of new religious buildings and restoration of destroyed churches throughout Russia began. In the early 90s, mosques began to be actively built in Tatarstan, Bashkortostan and other Russian republics with a predominantly Islamic population, but their architecture, for the most part, was not distinguished by any particular artistic merit. The interruption of tradition in the design and construction of religious buildings for more than seventy years caused this impact. The purpose of the article is studying the special features of modern Islamic religious architecture. Research objectives: to study various options of mosques buildings in the aspect of urban development of the existing territory; description of the possibilities of ornamental decoration of mosque interiors; the role of a mosque as the center of cultural and social life of residents of small settlements. Results. An analysis of implemented mosque projects both in the Russian Federation and abroad was carried out. Thus, when designing the construction and reconstruction of both cathedral and quarterly city and rural mosques, it is necessary to take into account the traditions of Tatar architects, the need to create a non-secular sacred image that does not copy Arab or Ottoman motifs. Conclusions. The results obtained on the basis of the examined examples of mosques allow us to trace their main features that form a sacred image that emphasizes national identity.

The creation of a comfortable living environment for city residents is directly related to the availability of areas for joint recreation and social contacts. People have the opportunity to meet and communicate in theaters, exhibition spaces, shopping centers and cafes, gyms, but the most complete interaction between people and recreation is possible, in our opinion, only in nature. In this regard, the development of recreational park areas within cities is significant. The purpose of the article is to consider a set of measures for the reconstruction of the Uritsky Park. The research objectives are studying the history of the park, the project for the reconstruction of the territory, formulating the basic principles for creating comfortable public spaces. Results. The analysis of the historical prerequisites for the development of the recreational area was carried out - it appeared around a lake of natural origin. The design of works for the reconstruction of the territory was carried out on the basis of public hearings to take into account the opinions of the majority of residents of the area. Thus, the following principles for the development of public urban spaces were formulated: functional zoning, citizen involvement; environmental improvement. Conclusions. The results obtained on the basis of the considered principles contribute to the formulation of effective recommendations for the reconstruction of other recreational areas within cities.

The article examines commercial apartment buildings and complexes of the turn of the XIX and XX centuries in the ethnic district of Kazan - the Old Tatar quarter. In the XXI century they began to fall into disrepair, some of them are completely lost. The relevance of the work is due to the need to research, study and preserve commercial apartment buildings and estate complexes in the development of the Old Tatar Qarter to ensure its sustainable development in the future. The purpose of the study is to identify their architectural identity using the example of the Apanaevsky Compound. The research objectives: to find out the identification codes of commercial apartment complexes (regularities of the location of objects in the structure of the Old Tatar Quarter, identification of architectural features, the nature of the functional filling of commercial apartment complexes and buildings, determination of the identity of the object under study). Results. A comprehensive analysis of the materials of object’s field surveys and historical and archival documents showed the multifunctional nature of the commercial appartment complexes of the Old Tatar Quarter. Following identification codes of the Apanayevsky Compound were determined: urban planning, architectural-historical, functional, national-ethnic, event, revealing its identity. Conclusions. The vast majority of commercial apartment complexes were located in the area of the Sennaya Square of the Old Tatar Quarter. As a rule, the main building of the complex was solved in an eclectic style, later - in Art Nouveau, remained unplastered in red or painted brick. The significance of the research for Kazan and the Republic of Tatarstan is to identify the architectural identity of the commercial apartment buildings of the complexes, manifested in identification codes. The commercial apartment complexes of the Old Tatar Quarter have value both as architectural objects and as monuments bearing an intangible component of the identity of Tatar culture and history. Their loss will negatively affect the historical appearance of Kazan and lead to the loss of sustainable development of this area.

Today, the problem of the development of the former outskirts of the city, “gray” zones, concerns many cities of the Russian Federation. A socio-economic imbalance has arisen between the areas of the city core and the former outskirts. In the process of industrialization, development and growth, the urban environment of core cities begins to move closer to the territories of former industrial centers, previously located on the outskirts. The purpose of this work is to propose an option for reorganizing the territory of the Flax Mill in Kazan. The research objectives are comprehensive urban planning analysis; development of the main provisions of the development concept of the study area; development of a territory planning project. Results. The characteristic features of the redevelopment of historically formed industrial territories have been identified. A comprehensive pre-design urban planning analysis of the territory bounded by the St. Nesmelov from the southeast, Proezd No. 21 Avenue from the southwest, the territory of the Zilantov Monastery and the borders of the Flax Mill territory from the northwest, St. 1 May and St. Gladilov from the northeast was carried out, which identified the resources and problems of the territory. It is proposed to create a cultural and creative quarter on the territory of the Flax Mill, taking into account the preservation of the “spirit of the place”, the placement of creative industries, the formation of a system of open public spaces, a comfortable pedestrian environment and the disclosure of the tourist potential of the territory.

Often, when comparing the results of field studies of cultural heritage sites with information from bibliographic sources, one has to deal with inaccuracies and errors in names, dates, and authorship. Determining the reliability of information reported about historical and cultural monuments is the central task of “historical criticism”. The purpose of the work is to determine the construction periodization of the Church of St. John Chrysostom in the village of Ivanovskoye (Republic of Tatarstan). The objectives include a brief historical and architectural description; comparison of archival materials and results of field studies of the church; clarification of the dating of the construction of the church. Results. Previously unpublished archival documents were introduced into scholarly discourse; а recurring error was identified in all bibliographic sources, i.e. incorrect dating of the construction of the church and the bell tower and incorrect identification of authorship. This error was discovered as a result of field research and proved by the found archival material with drawings and a brief description. Conclusions. A critical analysis of the sources made it possible to correct the error in the dating of the object. The example of this study demonstrates the possibility of reconstructing the stages of the “life” of an almost three-hundred-year-old monument based on a comparison of the results of field and bibliographic research.

When determining the principles of architectural and planning organization of research and production complexes, the main forms of which, in essence, are centers for testing technical systems, it is necessary to identify the functional and technological purpose of such complexes, as well as the main elements of infrastructure and their technical equipment. This article is devoted to the architectural and planning organization of the construction of specialized centers for testing technical systems. The functional and technological features of specialized centers for testing technical systems have been identified. The research objectives are to classify the main elements of the infrastructure of technical systems testing centers; determine their technical equipment; develop logistics schemes for the organization and interaction of the main elements of the infrastructure of technical systems testing centers. Results. Based on the analysis of world experience in the creation and operation of domestic and foreign laboratories, sites and test sites for testing the reliability of various materials, products and structures, the main elements of the infrastructure of the research object are classified, and their technical equipment is determined. Functional and technological features have been identified and logistics schemes for the organization and interaction of the main elements of the infrastructure of technical systems testing centers have been developed. Conclusions. The significance of the results obtained for architectural science lies in the fact that for the first time, functional and technological prerequisites have been identified, and logistics schemes for the organization and interaction of the main elements of the infrastructure of technical systems testing centers have been developed, which will make it possible to formulate the principles of the architectural and planning organization of such centers as a separate design object.

The revolution in Russia caused the process of development of industrial zones of cities. One of them is known in Kazan as Yagodnaya Sloboda. The relevance of this study is caused not only by the low level of study, but also by the inconsistency of existing historical industrial buildings with the requirements of modern industries and, as a result, their lack of demand, desolation and the need for reconstruction. At the same time, historical industrial sites are architectural and urban heritage and reflect the stages of industrial development in Tatarstan and Russia as a whole. Insufficient knowledge of industrial complexes does not allow making adequate decisions on their preservation and adaptation to modern requirements. The subject of the study is the stages of development of the spatial and planning structures of the territory under consideration, complexes and architecture of buildings. The research methodology includes the study of archival, bibliographic materials, cartographic analysis and field surveys of industrial facilities The purpose of the work is to study the historical architectural and urban planning aspects of the development of industrial territories and facilities in the “Yagodnaya Sloboda” district of Kazan on the example of the Alafuzovs factory complex. The objectives of the study are: 1. Conduct bibliographic and archival research on the subject of the study. 2. Based on the identified archival materials, trace the process of formation of industrial zones in the suburbs of Kazan on the example of the Alafuzovs factory complex in “Yagodnaya Sloboda” district and establish its features. 3. Compare the results obtained with the peculiarities of the development of similar industrial zones in other regions of Russia. Results: The work carried out made it possible to identify the features of the spatial and compositional development of the complex before the beginning of the XX century and its connection with the stages of development of industrial architecture of Tatarstan and the country as a whole. The conclusions of the study allow us to establish general patterns of development of industrial zones in the historical settlements of Kazan, as specific architectural and urban-planning formations of Russia in the second half of XVIII - early XX centuries.

A university campus is a multifunctional complex with hierarchical compositional and spatial connections at different levels of spatial planning organization. The article discusses the issues of forming the architecture of university campuses. Foreign and domestic experience in organizing their territories of architectural and spatial construction of the space-planning system of a university campus as a complex design object is analyzed. The purpose of this study is to develop principles for the integrated development of university campuses based on architectural planning models. The research objectives are identifying the main architectural and planning elements of the university campus and their types; the formation of a cross-cutting typology of university campuses and the creation of basic typological models for their further development; development of a conceptual proposal for the comprehensive transformation of the KSUAE university campus. Results. The architectural typology has been developed that identifies the main space-planning types of university campuses. The main functions and volumetric-spatial components formed in the compositional and planning structure of campuses as separate objects of research have been identified. The composition, principles of construction and placement of university campuses are analyzed and systematized.

The article aims to analyze the architectural buildings that constitute the social center of the neighborhoods in the central district of Beyoghlu, Istanbul. The study focuses on eight districts, which are divided into three regions: northern, central, and southern. The purpose of the work is to analyze the architectural buildings and historical districts of Istanbul, specifically Jihangir, Dolapdere, Kasimpasha, and Tarlabashi, considering their significance and contribution to the formation of the city’s social center. The objectives of the study are to analyze the role of each studied area in shaping Istanbul’s rich historical and cultural heritage, to investigate the changes and developments in these districts during the first decade of the 21st century and analyze their current state from architectural and social perspectives, to explore Istanbul’s role as a tourist center and examine how these historical areas attract the attention and interest of travelers. Results. The study highlights the geographical location of the Beyoghlu district in Istanbul and its historical importance as the city’s initial center. It focuses on various architectural elements, including theaters, public buildings, hotels, restaurants, squares, galleries, mosques, churches, and other religious structures that have played a significant role in shaping the community centers within the area. Conclusions. The article concludes by noting the changes that have taken place in the Beyoghlu area in recent years, including its transformation from a residential area to an entertainment centre. In general, the methodology of the article includes research and analysis of architectural features and historical context of the Beyoghlu district.

The formative spatial code of architectural solutions is the possibility of integrating artistic concepts, the worldview, the architect, city residents and other participants in the design process. The use of spatial code is universal regardless of the architectural style, the typology of the object, the creative method of the author, profile or conceptual designer. The awareness of where we are and what role we represent opens up the freedom of creativity and maturity of decisions. The object of the project search is space. The material elements are the boundaries that form this space. Everything that is and everything that happens between them is the subject of a project search. The article is devoted to the development of a single spatial code when creating architectural and other objects. An object is an architectural space. The aim of the research is to develop a universal spatial code for the creation of architectural objects that allow preserving their cultural tradition, taking into account the identity and trends of modern development of society. The following tasks are set in the study: to study the ways of forming an architectural object; to identify its main elements; to identify the boundaries of the possible application of a universal spatial code in the design process. Research methods: systematization, generalization of information from literary sources, graphical method of presenting information. The main results of the study represent that we found out the interrelation of formative elements in the process of creating an architectural object as a space. The study revealed the formation of an architectural object in its narrative time continuum. A single mechanism for creating architectural objects has been developed. The key elements of the architectural object are highlighted. The "part-whole" approach is indicated. Conclusions. The results obtained offer a universal and simple model for creating an architectural object, i.e. space.

The total accumulation of waste ash and slag mixtures today in the Russian Federation reaches about 1,5 billion tons. At the same time, only 1,5-2,1 million tons of annual emissions are recycled or used in various industries. It is obvious that in the coming years there will be a danger of large-scale environmental pollution, overfilling of ash and slag dumps, limiting the capacity of coal-fired generation and, probably, their removal from the energy balance. In this regard, the purpose of the work was to assess the effectiveness of ash and slag mixtures from thermal power plants for the production of building ceramics products. The objectives of the research include studying the properties of these mixtures and establishing the influence of technological factors on the strength of a raw ash ceramic sample during the drying process using the traditional production method of semi-dry pressing. Results. Using regression analysis, mathematical equations were obtained for the raw strength of samples based on ash and slag mixtures both before and after drying, depending on such technological factors as pressing pressure, molding humidity and specific surface area. The results of the main physical and mechanical parameters of ash ceramic samples after firing are presented: density, compressive strength and water absorption. Conclusions. The significance of the results obtained for the construction industry lies in the development of construction ceramic compositions based on such large-scale waste as ash and slag mixtures without changing the method of its production by semi-dry pressing. In terms of technological and physical-mechanical indicators, they meet modern regulatory documents and can be recommended for wide use in the production of ceramic products for construction purposes.

The development of hybrid polymer composites (with heterofiber filling) for structural purposes is inextricably linked with the need to increase the strength and stiffness characteristics of composites. For successful implementation of hybrid composites in construction practice it is necessary to improve modeling and evaluation of their stress-strain state at various stages of development. The aim of the study is to develop and evaluate the stress-strain state of products from hybrid composites made by vacuum infusion at three-point loading scheme. The objectives of the research are fabrication of composites from fiberglass, carbon fiber, and their hybrids; determination of physical and mechanical characteristics of composites; verification of analytical and numerical model with field tests. Results. Glass fiber-reinforced plastic, carbon fiber-reinforced plastic and hybrid composites with different combination of glass and high-strength carbon fibers and low-viscosity epoxy resin were produced by vacuum infusion method. Tensile, compression, interlayer shear, and three-point bending tests were performed and the physical and mechanical characteristics of the materials were determined, as well as the density, mass loss on ignition of the cured reinforced resins. A numerical model of multilayer composites was developed, the stress-strain state of beams was obtained, and verification of the analytical and numerical model with experiment was carried out under three-point loading scheme. Conclusions. The significance of the obtained results in the construction industry lies in the evaluation of the stress-strain state of hybrid composites for the purpose of further implementation in construction practice and it is recommended in solving scientific and engineering problems.

The development of the production of building ceramics is associated with the need to find effective technologies for replacing natural raw materials with industrial and household waste in the production of building ceramics. Compositions made from low-grade clay raw materials and ashes of various origins have recently been increasingly considered as a potential large-scale source of raw materials. However, the unsatisfactory rheological properties of molding compounds from clay-ash mixtures make it difficult to obtain high-quality building ceramics by plastic molding. The purpose of the work is to evaluate the possibility of controlling the rheological behavior of molding compounds from a clay-ash mixture by modifying them with silicon oxide hydrosol. The objectives of the research are to study the structural organization of ultrafine silica in an aqueous suspension, as well as to study the effect of silicon oxide hydrosol on the rheology of clay-ash molding compounds. Results. Through IR spectrometry, thermal and photocolometric analyses, optical and electron microscopy, it was established that silica sol contained in an aqueous suspension of sand after its processing in a ball mill plays the role of a surfactant in the clay-ash mixture, contributing to an increase in the thickness of the adsorption layer on the surface of ash and loam particles. Modeling of the combined influence of loam, ash and silica sol on the magnitude of the given deformations showed that SiO2 particles in a colloidal state provide a change in the ratio between free and bound water, which makes the molding mass more mobile and deformable. Conclusions. The significance of the results obtained for the construction industry is that in the processes of structure formation of clay-ash masses, silica sol contained in an aqueous suspension of sand should be considered as a nanostructured additive capable of effectively influencing the rheological behavior of molding masses and activating the processes of structure formation in the production of building ceramics.

In conditions of high traffic loads on road surfaces, the use of more durable asphalt concrete becomes necessary. This can be achieved by introducing asphalt concretes that are resistant to plastic and low-temperature deformations. Asphalt concretes made with bitumen-polysulfide binders have similar properties. However, to achieve the required effect, the amount of polysulfide introduced into bitumen should be up to 40% by weight. The purpose of the work is to develop a composition of organic polysulfide based on sulfur, higher fatty acids and amines, capable of increasing the technical characteristics of bitumen when introduced into bitumen in an amount of 5-10 wt.%. The objectives of the study are: selection of the composition of organic polysulfide; synthesis of organic polysulfide; study of the properties of bitumen binders modified with organic polysulfide. Results. At work presents the results of studies of bitumen modified with organic polysulfide based on sulfur, polyamines and higher fatty acids. The structure of organic polysulfides has been studied. Using optical and electron microscopy, it was established that the resulting polysulfides have a crystalline structure. Conclusions. It has been established that modification of road bitumen with polysulfide based on sulfur, polyamines and higher fatty acids in an amount of 5% allows increasing the softening temperature, as well as the adhesion of the bitumen binder to the mineral material.

One of the ways to introduce hybrid (with heterofiber filling) polymer composite materials of structural purpose into the construction practice is to improve their numerical modeling of the stress-strain state at various stages of development, which allows performing a preliminary assessment of optimal options at an early stage. The purpose of the study is to determine the ultimate load that the composite will withstand in bending, tension and compression, to assess the influence of the content of different phases with recommendations for the assignment of geometric parameters and mechanical characteristics of the composite. The objectives of the research are performance of strength calculations in tension, compression, bending of hybrid beams, comparative analysis of different reinforcement on strength and stiffness parameters, preliminary evaluation of the optimal variant of reinforcement of hybrid composite. Results. Numerical modeling of stress-strain state of hybrid polymer composite materials, namely, tensile, compression and bending calculations have been carried out. Comparative analysis of different reinforcement on strength and stiffness parameters has been carried out. The method of preliminary estimation of the optimal variant of reinforcement of hybrid polymer composite material has been analytically developed. Conclusions. The significance of the obtained results in the construction industry lies in the fact that numerical modeling of the stress-strain state of hybrid polymer composite materials allows expanding the field of their application, the model is recommended to be used in solving scientific and engineering problems.

The object of the study is the lining blocks of the tunnels of the Kazan metro. The metro is a structure of the most important economic importance. Therefore, increased durability requirements are imposed on it. The durability of structures, in turn, depends on the durability of the building materials from which they are made. The purpose of the work is to assess the actual strength of concrete in the Kazan metro tunnels manufactured in different periods and to construct a kinetic curve of changes in strength over time. The objectives of the study are: the formation of a database of controlled parameters and the creation on their basis of a predictive model of changes in the characteristics of the structure during operation. Results. In the work, a function was obtained that makes it possible to predict the change in the strength of reinforced concrete blocks of the lining of the Kazan metro during operation. Analyzing the data for the 22-year period of operation, an increase in strength by 20.8% was found in relation to the design indicator. This result testifies to the positive dynamics of the durability of reinforced concrete structures and indicates their continued use in the future. Conclusions. The results of the study will allow us to draw conclusions about the most effective methods of selecting asphalt concrete from the point of view of resistance to the formation of a plasticity track. The data obtained can be used in the construction and operation of the road surface to increase its durability and stability. Conclusions. The results of the study allow us to conclude that the durability of the considered reinforced concrete lining blocks depends on the technical condition of their elements.

It is known to use individual modifiers – water repellents from a number of organosilicon compounds to improve some technological and operational properties of soil-cement. However, systematic studies on the influence of the structure and volume of the aliphatic radical in organosilicon compounds on the efficiency of modification of road soil-cement have not been carried out. The relevance of the study is justified by the need to ensure the required level of strength and frost resistance of cement-soil layers of road pavements in road-climatic zones with seasonal and daily temperature changes, especially with frequent transitions through 0 °C. The purpose of the work is to analyze and study the effectiveness of the influence of organosilicon compounds, differing in the volume of aliphatic radical, on the physical and mechanical characteristics of road soil-cement. Results. It has been established that modification of soil-cement with potassium propyl and methyl siliconates provides an increase in the compressive strength in the range from 30 to 45 %, the tensile strength in bending from 28 to 40 %, and the freeze-thaw resistance coefficient from 64 to 88 % compared to unmodified compositions. It has been shown that at equal levels of strength parameters of modified soil-cement, the influence of potassium propyl siliconate contributes to a more significant increase in the level of frost resistance – by 10-20 %. Conclusions: The positive effect of modification with water repellents - organosilicon compounds containing an alkyl radical, differing in structure and volume - has been shown. It has been established that the highest level of freeze-thaw resistance and strength is provided when modified with organosilicon compounds containing propyl radical (C3H7). It has been revealed that with an increase in the volume of the radical of an organosilicon compound, it is possible to reduce the optimal content of the modifier in road soil-cement while increasing the characteristics of road pavement materials. This pattern is confirmed by the results of determining the optimal content of the studied modifiers, in which there is a 20% decrease in the amount of potassium propyl siliconate compared to potassium methyl siliconate for different compositions of soil-cement.

Children are the most vulnerable road users who are at increased risk of injury as a result of road accidents due to the simultaneous impact of multiple risk factors. The road situation near educational institutions is quite difficult for children to perceive. The purpose of this study is to determine the level of road safety near educational institutions. The main objectives of the study are to identify problem areas in the field of road safety and to survey the engineering support of the road network near educational institutions. Results. To determine the level of road safety in the vicinity of educational institutions, we pointed out the main criteria by which the assessment was carried out. The assessment of the organization of traffic near 27 educational institutions of Kazan, Naberezhnye Chelny and Bolgary was carried out by the method of a full-scale survey. Conclusions. Road infrastructure and traffic management are of great importance in the field of road safety near educational institutions. An assessment of the organization of traffic near 27 educational institutions showed that, in general, there is a positive trend in the field of road safety today. Collecting and analyzing data on road safety and key performance indicators of the road network around educational institutions is an important step to support and improve the effectiveness of road safety decision-making and cost-effective measures.

The purpose of this study is to determine the capacity of traffic lanes at an unsignalized junction at the same level with pedestrian traffic at different positions of the pedestrian crossing on the main road. The objectives of the study are the application of the developed mathematical model of traffic and pedestrian flows at an unsignalized junction at the same level in accordance with the proposed hierarchy; the development of computational schemes for the movement of cars and pedestrians; the determination of the capacity of the lanes of the secondary road. The article presents the results of the study of the influence of the pedestrian crossing position on the main road on the capacity of the right-turning direction of a secondary road. The study was carried out by the method of mathematical modeling of the movement of cars and pedestrians at an unsignalized junction according to the developed schemes. The mathematical model takes into account the priority of movement at an unsignalized junction and it is a complex system of stochastic-deterministic equations. The proposed model and the results of the study can be used to determine the capacity during the design, reconstruction and overhaul of unsignalized junctions at the same level with pedestrian traffic, as well as when choosing the location of a pedestrian crossing on the main road.

A constant increase in traffic load and traffic intensity leads to a decrease in the resistance of asphalt concrete to rutting and other defects. The use of crumb rubber in road construction is one of the promising methods for recycling waste and improving the characteristics of asphalt concrete. The purpose of the work is to study the physical and mechanical properties of bitumen modified with crumb rubber (rubber-bitumen binder). The objectives are to study the influence of the amount of crumb rubber and preparation time on the physical and mechanical properties of rubber-bitumen binder; determine the composition of rubber crumbs using IR spectroscopy. Results. Depending on the amount of rubber crumb and preparation time, the following physical and mechanical properties of the rubber-bitumen binder were studied: needle penetration depth at 25 °C, softening temperature along the ring and ball, ductility at 0 °C, Fraas brittleness temperature. Determination of the amount of cellulose and crumb rubber was carried out by IR spectroscopy. Conclusions. It has been established that with the introduction of additives RK-1, RK-2 and RK-3 into bitumen in the amount of 8 to 24% and preparation time of 5 to 15 minutes: penetration at 25 ° C decreased by 14.92%, 17.19%, 12.90%; the softening temperature increased by 12.47%, 23.12%, 18.23; ductility at 0 °C decreased by 32.43%, 23.68%, 37.50%; the brittleness temperature increased by 31.25%, 34.54%, 35.71% respectively. It has been established that the main component (at least 80-90% by weight) in all three samples of rubber crumb is cellulose, as evidenced by the intense characteristic peak of 945 cm-1 of pyranose cycles, which is the main structural unit of all high-carbohydrates and, in particular, cellulose.

The use of modern methods of numerical simulation (CFD-methods) for investigation indoor air fields makes it possible to calculate the air distribution and determine the necessary air exchange for complex ventilation flows in public buildings, such as theaters, ice arenas, atriums. In particular, CFD-methods make it possible to obtain the air exchange coefficient for flows with simultaneous action of free and forced convection, that is, where classical approaches have no solution. At the same time, in order to increase the validity level of CFD-methods for ventilation purpose, it is necessary to show their reliability. The objectives of the study are to compare the results of using classical methods for calculating air exchange and the method of CFD simulation for various air distribution schemes: air supply by inclined jets, from top to bottom by jets spreading on the ceiling, horizontal constrained jets, into the occupied area with low-speed velocity. Results: it was found that the differences in the values of the air exchange coefficient by temperature obtained with numerical simulation and the most accurate of the classical methods ranged from 2% to 5%, depending on the air distribution scheme.

When designing ventilation systems in modern buildings, atypical schemes that include a large number of shaped elements are increasingly used. At the same time, the aerodynamic calculation is carried out using the local resistance coefficients of single elements, when their mutual influence on each other is not taken into account. The purpose of the study is to determine the influence of the settings and models of the computer complex on the adequacy of modeling the flow in a node consisting of a sequentially located exhaust hole and elbow. To achieve this goal, the following tasks are solved: determining the influence of the numerical model settings on the convergence of the iterative process; validation of the KMR values and outlines of vortex zones obtained using different combinations of turbulence models and wall functions, average velocity in the exhaust channel, for design options - “straight”, “long” and “short” channel. Results. The influence of the combination of turbulence models and near-wall functions on the adequacy of the resulting flow in a node containing an elbow and an exhaust hole at different speeds was determined, flow patterns and outlines of vortex zones were obtained for the considered node configurations, and local resistance coefficients were calculated. Conclusions. The results of the study indicate that closely spaced elements have a significant impact on the overall resistance of the node. This fact must be taken into account when performing aerodynamic calculations of ventilation and air conditioning systems.