Problem statement. A promising method for improving the properties of cement composites is to fill the matrix of the cement binder with highly dispersed mineral particles of various genesis and morphology. The effectiveness of mineral additives increases when such particles act as a seed, i.e. active centers around which newly formed structural elements of the cement stone are grouped, helping to strengthen the contact zone between the cement stone and the filler. At the same time, information on the state of structuring additives in activated solutions, on the effect of their dispersion on the structure and strength characteristics of the cement stone is extremely limited, which complicates the development of scientifically sound approaches to achieving the target effects of improving the physical and mechanical properties of concrete products. The purpose of the work is to quantitatively assess the effect of ultrasonic treatment of aqueous suspensions of mechanically activated wollastonite on changes in the structural-phase parameters and strength characteristics of the cement stone. The following objectives of the study are distinguished: the effect of sequential mechanical and acoustic treatment on the particle size of the dispersed phase of aqueous suspensions was studied; the effect of the dispersed composition of mechanoacoustically activated wollastonite on the phase composition and strength characteristics of cement stone was investigated. Results. As a result of successive mechanical and acoustic treatment, the dispersed phase is discretized to sizes less than 1 m. It was found that the use of aqueous suspensions with mechanoacoustically activated wollastonite for cement mixing helps to increase the mechanical strength of cement stone compared to the control sample. The mechanism of the strengthening effect of the additive is clarified by the results of X-ray phase analysis and assessment of the parameters of the pore structure of cement stone. The data obtained confirm the hypothesis about the role of nanoscale wollastonite particles as active crystallization centers, around which newly formed minerals of cement stone are grouped, promoting the strengthening of cement stone. Conclusions. The significance of the results for the construction industry is that mechanoacoustic treatment can be used to increase the activating potential of mineral additives used to modify cements.

Problem statement. Currently, there is an increase in the use of building materials based on gypsum binders in the reconstruction, repair and new construction of buildings. Unfortunately, high water absorption and low water resistance of this material limit its use for outdoor work. One of the ways to solve this problem is to use surface or volumetric hydrophobization. The purpose of the work is to evaluate the effectiveness of hydrophobing agents for gypsum cement-pozzolan concrete. For this purpose, the following tasks were solved: studying the effect of various hydrophobic liquids on the technological, mechanical and hydrophysical properties of fine-grained gypsum cement-pozzolan concrete with surface and volumetric modification; establishing an effective type of hydrophobing agent and the optimal amount. Results. The paper presents the results of studies of the effect of hydrophobing agents of various compositions on the properties of gypsum cement-pozzolan concrete. The main results of the study showed that surface hydrophobization slightly increases the average density of concrete (by 1-3%). At the same time, the increase in compressive strength was 6%, and in bending - 28% relative to the control samples. At the same time, an increase in the softening coefficient by 7% and a decrease in water absorption by 53% were noted. Volumetric hydrophobization of gypsum cement-pozzolan concrete made it possible to increase the softening coefficient of products based on the studied type of mixtures to one, reduce water absorption to 79%, increase compressive strength by 15% and bending strength by 41%. Conclusions. The significance of the obtained results for the construction industry is that the possibility of using hydrophobic additives to improve the water resistance and strength of gypsum cement-pozzolan concrete has been substantiated.

The efficiency of using fiber-reinforced polymer composites, in particular fiberglass, in elements of building structures operating under constant long-term loads is determined by the resistance to creep deformation. The latter depends on the degree of fiber orientation in the direction of mechanical stress, which is specified during the design of the product (structure). In case of deviation, i.e. misalignment due to technological reasons, long-term deformations increase. In this regard, it becomes relevant to study the effect of the initial (during manufacture) misalignment on the creep of fiberglass products, which was the purpose of this work. The objectives were to experimentally study the creep of flat and tubular fiberglass samples with different degrees of fiber misalignment, determine the difference in the creep modulus in flat and tubular samples, and formulate design recommendations for reducing the creep of fiberglass products during their operation under load. It has been established that misalignment of the reinforcement direction from that provided by the design leads to a significant increase in creep deformation during tension of fiberglass elements (flat and tubular) compared to the same deformation characteristics of similar elements with the designed reinforcement directions. At the same time, under the action of constant tensile stress, with the same reinforcement angle, the creep resistance during tension of tubular elements is greater than that of flat ones. A design method is proposed for solving the problem of optimal design of fiberglass flat and thin-walled tubular elements, on the deformations of which restrictions are imposed.

Problem statement. In concrete and reinforced concrete structures, when eliminating defects and damages using polymer technologies, it is necessary to take into account the features of the physical-chemical processes occurring at the interface of the “substrate (concrete) – adhesive” phases. However, these features are not taken into account in the technologies for repairing defects and damage to building structures. The relevance of the study is due to the need to provide designers and technologists with the knowledge to select reliable polymer repair materials. The purpose of the work is to substantiate the choice of the type of modifiers for epoxy–amine compositions that can be cured without heat supply and to develop compositions for repairing concrete and reinforced concrete structures that eliminate negative processes and provide a high level of adhesion and strength characteristics exceeding the level of foreign repair compositions-analogues. The following tasks were solved: to consider the features of amine curing of the mixture of epoxy oligomers and oligoester cyclocarbonates; to determine the effect of oligoester cyclocarbonates in the structure of epoxydiane oligomers and the contribution of hydroxyurethane fragments to the processes of physical-chemical modification of polymers; to develop import-substituting modified epoxy-amine compositions for the repair of reinforced concrete pressure pipes and other defective building structures that increase the levels of required strength and durability of building structures. Results. It has been established that modification of epoxy-amine compositions as a result of the formation of hydroxyurethane structures prevents the formation of “weak” boundary layers of highly polar substrates and prevents the processes of selective sorption of adhesive components. The developed composite composition surpasses its foreign counterpart Araldit K-79 Kit (Ciba Geigy, Switzerland) in terms of the set of characteristics. Conclusions. The significance of the results obtained for the construction industry lies in expanding the possibilities of choosing and using repair epoxy adhesive compositions that increase the reliability and service life of concrete and reinforced concrete elements in critical structures (tunnel finishing blocks, pressure pipes, etc.).

Problem statement. The safety of buildings and structures depends on the reliability of the foundation. When designing foundation bases, the question of the deformation characteristics of soils arises. Gray clays are the least studied at the moment, since in their natural state they lie at significant depths, and were not previously included in the compressible thickness. The main goal of this study is to identify the features of the deformation of gray clays of a disturbed structure under triaxial loading at different values of humidity, the value of exposure in a desiccator and the presence of the first stage of loading. The main objective of this study is to identify the deformation features of gray clays with a damaged structure under triaxial loading at different humidity values, the length of exposure in a desiccator, and the presence of the first loading stage. To achieve this goal, the following tasks were solved: identical samples were created from clays with a damaged structure; triaxial experimental studies were conducted; the ultimate strength of the samples and deformation characteristics were determined; graphical dependences of strength, deformation modulus, and shear modulus on humidity and loading conditions were shown. Results: Experimental studies were performed on samples, made of soil with a disturbed structure. Three values of specified humidity are adopted: 38%, 40% and 42%. The first stage of loading simulates the presence of soil defects in the form of a plane of destruction. The main results of the studies are new data on the development of vertical deformations and modules of general deformations, also shear modules under triaxial loading conditions depending on different values of soil moisture, the time of holding the samples in a desiccator before testing, the magnitude of lateral pressure and the presence of the first stage of loading. An analysis of the research results was performed and some patterns in the behavior of clay soils under triaxial static loading were established. Conclusions: Establishing the influence of humidity, holding time, lateral pressure value and the presence of the first stage of loading on the development of vertical deformations and on changes in the moduli of general deformations and shear of a clay soil sample under triaxial compression conditions is an important task for the construction industry.

Problem statement. In weak clay soils, the effectiveness of the improvement technique using crushed stone columns may be limited due to insufficient lateral pressure on the soil. The crushed stone columns should be reinforced by providing the minimum required lateral confining pressure. Plaxis 2D 20 software package was used to verify the numerical analysis. The numerical model was validated based on previous studies and the same material properties and boundary conditions were chosen for the analysis as in the experimental study conducted by A. P. Ambili and S. R. Gandhi [21]. After confirming the validity of the model, four variants of concrete and crushed stone composite stone columns were considered keeping the same material properties and boundary conditions. The aim of the present study is to investigate and evaluate the effect of concrete part on the behavior of concrete-crushed stone composite stone columns compared to conventional crushed stone column. This is accomplished by comparing experimental and numerical results, including the following objectives: 1. To compare the results of the conventional stone column study with the previous experimental study to confirm their consistency and accuracy; 2. To modify the form of the numerical simulation while maintaining all established material properties and boundary conditions. Results: The paper presents the results of numerical investigations of the bearing capacity of concrete and crushed stone composite columns with increasing concrete part within the range of 0.5 to 2.0 stone column diameter. The results showed that the vertical stress increases with increasing the length of the concrete part. The concrete part increases the stiffness of the crushed stone column, which in turn increases its bearing capacity. When the length of the concrete part approached half the length of the crushed stone column, the stress doubled to 2000 kPa at 30 mm settlement. The maximum bulging of the crushed stone column occurs at a depth equal to approximately one stone column diameter, which proves that the horizontal deformation decreases with increasing length of the concrete part of the stone column. Conclusions: The significance of the results obtained for the construction industry lies in the fact that the concept of composite concrete-crushed stone columns successfully combines the advantages of various conventional crushed stone columns. These stone columns have a high bearing capacity superior to that of conventional crushed stone columns, and this is achieved at a competitive price. In addition, composite concrete-crushed stone columns show better bearing capacity compared to bored piles of similar diameter and length. In addition to these advantages, composite concrete-crushed stone columns provide significant resistance to bulging failure. The level of deformation associated with bulging decreases as the length of the concrete portion increases. Also, the stiffness of the concrete-crushed stone composite column increases if the concrete portion is located close to the ground surface.

Problem statement. Ensuring the strength and reliability of prefabricated buildings directly depends on the design solution, strength and deformation characteristics of vertical and horizontal joints, technology and quality of their execution. This task becomes more complicated when designing buildings, taking into account the progressive collapse, predetermining the need to modernize standard solutions. The necessity of developing solutions that increase the resistance of large-panel buildings to emergency impacts leading to instant or prolonged destruction of individual structural elements and assemblies is considered. Due to the presence of elements of the loop joint that differ in nature and properties, this connection of elements of prefabricated load-bearing systems undergoes a complex stress state during an emergency. The purpose of the work is to determine the stress-strain state of the loop joint of wall panels during progressive collapse. The objectives of the study are: determination of maximum stresses in the elements of a large-panel building with progressive collapse; numerical modeling of a loop joint and analysis of its stress-strain state; development of structural solutions for the joint, taking into account the identified features of its operation. Results. The maximum efforts in the panels and joints of the modernized structural solution of a large-panel building in case of emergency impact are determined, and options for upgrading the structural solutions of the loop joint are proposed. Multifactorial numerical modeling of the loop joint was carried out, taking into account the work on emergency impact, strength and deformation characteristics were determined. A solution has been proposed for the design of a loop joint for load-bearing systems, taking into account their operation during progressive collapse. Conclusions. The significance of the results obtained for the construction industry lies in the fact that the proposed option for the modernization of a typical solution and the results of the study can be used in the design of loop joints of large-panel buildings designed taking into account progressive collapse.

Problem statement. The main problem of the study is to ensure the structural safety of long-span unique buildings and structures using spatial shell structures made on full-scale structures subjected to long-term static and short-term dynamic impacts of a high level. The purpose of the work is to simulate the behavior of various geometric shapes of reinforced concrete spatial shell structures under static and dynamic effects of high intensity in order to identify characteristic features and ensure structural safety at the construction and operation stages. The objectives of the research are: ensuring operational safety using the modeling method, investigating changes in the structural properties of materials and dynamic parameters, assessment of the impact of climatic conditions, flexibility of structures, taking into account the presence of damage; study of external influences, introduction of stiffening elements to ensure seismic resistance and operational safety. Results. The paper proposes a method for ensuring the structural safety of long-span unique buildings under prolonged operational and seismic impacts of varying intensity, the introduction of spatial stiffness elements, the inclusion of which contributes to the exit from the resonant state of the spatial system. Conclusions. The significance of the results obtained for the construction industry lies in the possibility of ensuring the structural safety of long-span unique buildings at the stages of construction and operation, which makes it possible to expand the scope of effective types of spatial shell structures in regions with difficult natural and climatic conditions.

Modern, reliable and efficient civil buildings are constructed mainly from monolithic reinforced concrete directly at the construction site. The nature of the work of monolithic reinforced concrete structural systems is, as a rule, repeatedly statically unchangeable systems. The calculation of statically unchangeable systems largely depends on the loads applied to the system, determined at the design stage. But over time, the loads on the floor, physical and mechanical properties of concrete and reinforcement, as well as the characteristics of their bond can change. The purpose of this work is to determine the bond of periodic profile reinforcement to concrete at a real facility with changing operational loads. The following tasks are solved in the course of the work: conducting an experiment on an existing structure, analyzing the stress-strain state of reinforcement and concrete under a changing load, identifying the most dangerous limiting factors (destruction and deformation) affecting such structures. The object of the study was a monolithic reinforced concrete beamless floor slab in an operated building, the frame of which was 8 years old at the time of the experiment. Results. Experimental control systems (sensors and deflection meters) confirmed the alignment between the experimental data and the theoretical behavior of reinforced concrete structures. Features of the redistribution of forces in the span and support zones of the slab were identified, which is associated with the yield of the reinforcement in the span zone. The continuous application of short-term loads, which is especially prevalent in shopping and entertainment complexes, significantly affects the behavior of statically indeterminate reinforced concrete systems. In certain situations, such as specific combinations of short-term loads or their movement, a sudden release of surface energy may take place, resulting in the formation of new surfaces in the form of cracks. This also leads to increased deflections due to a decrease in stiffness in certain parts of the structure. Conclusions. An experimental loading of the existing floor slab was performed using a strip load. The results showed that short-term displacement loads present the highest risk to flat reinforced concrete floor slabs. Scientifically, it is crucial to examine the processes taking place in the “concrete-reinforcement” interaction zone. Practically, design engineers must pay increased attention to the design of reinforced concrete beamless floors.

Problem statement. With the development of industrial infrastructure and the expansion of construction in various regions, there is a growing need to address the design of unique, long-span buildings, development of efficient structural solutions for roof shells, methods of their erection, the study of stress-strain state, the development of theory and methods of modeling. These aspects hold critical importance for the national economy. The purpose of the work is to develop effective structural solutions for long-span unique buildings by combining methods for installing shells using continuous scaffolding with sparse supports with methods for enlarging mounting elements for spans from 60 to 100 m and over 100 meters. The objectives of the research are: analysis of the stress-strain state of beam and shell systems during construction stages; application of the modeling method to study and evaluate the stages of work, the rationality of installation methods, and dismantling of shells; ensuring the structural safety of spatial systems in installation states. analysis of the effectiveness of using rational technology for the construction of shells, development of a method for calculating shells taking into account the stages of construction. Results. The paper presents the results of studies of long-span shell roof structures of unique buildings. Effective design solutions for building roof shells with a span of up to 60 m have been developed using the method of installation of enlarged elements. For spans from 60 to 100 m and over 100 m, they have been developed using a combined method of shell installation using continuous scaffolding with sparse supports with methods of enlarging installation elements. The stress-strain state has been studied using experimental modeling methods, a calculation method and rational methods of construction have been developed. Conclusions. The significance of the results obtained for the construction of long-span unique buildings lies in the fact that due to the introduction of architecturally expressive forms of coating shells, ensuring their economic efficiency, taking into account regional characteristics, the construction industry is developing and expanding in this direction.

Problem statement. Steel reinforced concrete structures have been widely used in slabs in recent years. The design of steel reinforced concrete slabs in our country today is carried out in accordance with the requirements of current regulations. In this case, the design models are based on stress diagrams of normal section of triangular and rectangular outline, which leads to distorted calculation results from the actual load-bearing capacity. The aim of the research is to develop the theory of calculation and new methods of strength calculation. The tasks of the research are the analysis of structural solutions of steel reinforced concrete slabs, development of new methods of calculation reflecting the actual stress-strain state of the normal section of the main bearing elements of the slab. Structural solutions of steel reinforced concrete slabs are analyzed. Slabs and anchor links in them are considered according to the authors’ patents with the analysis of their work. Numerous tests show that curvilinear outline stresses occur in the normal section of the bending element. It is proposed to calculate the strength of steel reinforced concrete elements on the basis of stress diagrams, approximated to the actual stress-strain state of sections. Results. Analytical dependences of strength estimation of steel reinforced concrete slabs on the basis of stress diagrams close to the actual stress-strain state of sections are given: trapezoidal diagrams based on limiting relative deformations of concrete compression and curvilinear diagrams of concrete of the compressed zone of the bending element. Analytical dependences of the stress-strain state of the contact between the top chord of a steel beam and a concrete slab are given. A shear force occurs at the contact, which leads to a complex stress-strain state of concrete and anchor rod. Dependences for determination of stresses in concrete and anchor rod are given, anchor bending and tensile bending of anchor rod are considered. Conclusions.Calculation according to the proposed dependences will allow increasing the reliability of the structures and obtaining cost effective solutions of slabs.

Problem statement. The indoor microclimate during the cold period of the year has been studied in sufficient detail, and the method of its provision is described in the relevant regulatory documents. The formation of the indoor microclimate during the warm period of the year has not been sufficiently studied and regulatory documents have not been developed to date. The reason for overheating of premises and the occurrence of thermal discomfort is solar radiation penetrating the premises through light openings. At the same time, the larger the glazing area is, the more solar energy will enter the premises and the more the air temperature will increase in it. In connection with the above, the study of the patterns of formation of the indoor microclimate in the summer months is a very urgent task. The purpose of the work is to analyze the existing scientific base in the field of sun protection and assessment of overheating of premises by solar radiation. The objectives of the study are: comparison of existing methods for calculating indoor temperatures under the influence of solar radiation, as well as sun protection methods; comparative analysis of Russian and foreign methods for determining the duration of overheating based on the criterion of thermal comfort; to determine further vectors for the development of sun protection using architectural and structural methods based on an analysis of research results published primarily over the past 3-5 years. Results. It was revealed that the current regulatory documentation does not contain a standard calculation method for determining the indoor air temperatures under the influence of solar radiation. The duration of the period of overheating of premises by solar radiation is not assessed based on the criterion of thermal comfort, but is reduced to a formal assessment of the value of the external total annual solar radiation. In this case, the calendar periods of sun protection coincide with the dates of insolation. The standard method for designing sun protection using Shading Devices is currently not applicable due to the lack of reference data on the solar factor of Shading Devices of various types. A standard method for determining the solar factor for Shading Devices of various types has not been developed. There is no method for designing enclosing structures using phase-change materials as one of the methods of sun protection. Conclusions. The article shows the need for scientific development of methods for calculating the indoor air temperature when a room is irradiated with solar radiation to determine the actual period of overheating and design shading devices.

Problem statement. The acceleration of technological changes and the increase in requirements for the efficiency and reliability of structures in the 21st century require a revision and improvement of methods of structural mechanics. In addition, the study of the deformation processes of materials such as concrete, graphite, polymers, (rocky) soils and others has shown that their mechanical behavior differs in many ways from traditional concepts. Thus, the development of new reliable computational models describing the behavior of such materials is becoming increasingly relevant. The purpose of the study is to develop an improved method of strength analysis based on finite element calculation of combined systems in the form of a building on a multilayer elastoplastic base. The sensitivity of the physical and mechanical characteristics of materials to the type of stress state, the development of plastic deformations in the reinforcement, damage, induced heterogeneity, cracking are taken into account. The objective of the study is to obtain quantitative estimates and to compare the results with other common methods of determination of the stress-strain state of a reinforced concrete residential building located on a base of several layers of rocky soil, taking into account a complex of loads including seismic and wind impacts. Results. A new method for calculating combined “building-base” systems has been proposed, using new theoretical approximations for deformation diagrams of rocky soils. The developed flat hybrid finite element has been fully described. The stress-strain state of combined “building-base” systems under various loads has been calculated according to current regulations for special load cases. Conclusions. It has been shown that accurate calculation of the mechanical behavior of materials is crucial for obtaining an accurate forecast of the stress-strain characteristics of the “building-base” system under complex load conditions. The reliability of the obtained results was assessed by comparison with calculations in modern software packages and simplified theories.

Problem statement. The greatest potential for the development of inner-city territories is in the inefficiently used territories of the “gray belt” - industrial zones of cities. Because of the absence of free places for construction, as well as in order to preserve the “spirit of the place”, “memory of the place” and authenticity of the architectural environment, the prospects of redevelopment of historically developed industrial areas of the city are considered. The purpose of the work is to demonstrate the architectural and urban planning potential of the redevelopment of the part of the industrial territory of the Kirovsky district of Kazan. The objectives of the study are to study the prerequisites for the renovation of industrial facilities; identification of key approaches to the renovation of industrial facilities; to form an architectural image of the territory of the “Yagodnaya” settlement in Kazan, which allows reflecting the “spirit of the place”. Results. The paper presents the features of the organization of redevelopment of historically developed industrial zones; based on the study of architectural and urban planning potential, a matrix of phased reconstruction of the territory was developed, including measures for the ecological rehabilitation of the water body, increasing the connectivity of the territory, the development of housing and a system of open urban spaces; а unique architectural image of the chosen territory was proposed, contributing to the preservation of the architectural authenticity of the territory and the manifestation of the industrial “spirit of the place”. As a result of the implementation of the proposed method of redevelopment of the industrial territory, the problems of stagnation of the industrial territory of the “Yagodnaya” settlement will be solved and its attractiveness will be improved. Conclusions. An integrated approach to the development of historically developed industrial zones of the city, including the manifestation of local territorial identity and which is expressed in the competent redevelopment of industrial facilities, can contribute not only to the development of the economy and their effective development, but also to the emergence of new areas of human activity.

Problem statement. The acoustics of the classroom, in particular articulation (speech intelligibility), affects the perception of educational information. Speech intelligibility can be assessed both at the design stage and in-situ indoors, however, the parameters underlying these techniques differ, and therefore the results may differ. The aim of the work is to find the relationship between speech intelligibility in classrooms of various typologies with their architectural parameters. To achieve the goal, the following tasks were solved in the work: – to evaluate speech intelligibility in classrooms using full-scale and computational methods; – to evaluate the convergence of different methods; – to identify the relationship between the various architectural parameters of classrooms and the intelligibility of speech in them. Results. The spread of articulation values in the same room with different listeners can be several tens of percent. The study showed that the human factor (lack of interest in the experiment, distracting and interfering behavior of children, hearing acuity, etc.) can make a much greater contribution to speech intelligibility than the spatial planning and acoustic characteristics of the room. Conclusions. The paper shows that in order to achieve higher values of speech intelligibility in classrooms, preference should be given to more compact rooms with smaller dimensions and fewer seats, which will reduce the distance of listeners from the speaker and minimize the opportunity for listeners to communicate with each other and, as a result, improve information perception.

Problem statement. The study of art objects in the urban environment is extremely relevant, since cities act as important cultural centers, attracting the attention and interest of both local residents and tourists. In conditions where many things are standardized and monotonous, the use of national traditions can give such objects a special atmosphere and zest. This contributes to the development of creative thinking of designers and allows them to go beyond the usual styles and themes. There is a lack of methodological foundations for creating objects with a national component in the urban environment. The aim of the study is to formulate the principles of designing art objects taking into account the manifestation of national traditions. The objectives are to reveal the concept of “art object” in environmental design, to determine the characteristic features of the national component and to identify the design features of art objects with a national component. Results. The main results of the study are that the principles for designing art objects in the urban environment are presented, taking into account the manifestation of national traditions, which will allow preserving and presenting cultural heritage in a new light. Conclusions. The significance of the obtained results for design of the architectural environment is that they provide recommendations and rules that help designers and artists to create art objects with a national component. The study of design principles can inspire new ideas and solutions, being a link between design, architecture and art.

Problem statement. The study of the creative method of prominent Kazan architects in the 1950s is necessary for understanding the regional features of the formation of Soviet architecture of this period and the creation of professional tools for their subsequent use in the modern architecture of Kazan. The aim of the study is to determine the design methodology of prominent Kazan architects in the 1950s using the example of iconic public buildings in Kazan. Research objectives: to identify public facilities built in the 1950s in Kazan which have the most expressive regional ornamental complexes in terms of their use and conduct their field survey; to study archival and bibliographic sources on the research topic; to analyze the design methodology of Kazan architects in the context of national and regional traditions in the specified period. Results. As a result of the conducted research, the following most expressive public facilities from the point of view of the use of regional ornamental complexes were identified and examined: the building of the Kazan Fair, the building of the Kazan State Medical University, the M. Jalil Opera and Ballet Theatre, the Sakhibgarey Said-Galiev cultural activities centre. Visual graphic tables containing fragments of facades and interiors of the facilities under study were compiled, and the design methodology of Kazan architects was analyzed. Conclusions. The creative method of prominent Kazan architects in the 1950s of the Soviet period was based on the synthesis of regional heritage and techniques of classical architectural and artistic style, as a result of which a unique ornamental decorative system was developed, which became the property of the architectural culture of Tatarstan. The historical ornamental complexes used in the Soviet period were predominantly of plant origin and were introduced into compositionally important parts of facades (capitals, niches, cornices, frames of openings). The method of facades design, as a rule, did not depend on the functional content of the facility.

The relevance of this study is determined by the lack of scientific works dedicated to the oeuvre of the provincial architect F.I. Petondi and the absence of reconstructions of his projects, which complicates the understanding of the architectural heritage of the first half of the 19th century in Kazan. The study of the Rodionovsky Institute for Noble Maidens aims to fill this gap and shed light on significant aspects of regional architecture. Problem statement. The article is devoted to the study of the first project of the Rodionovsky Institute of Noble Maidens in Kazan, designed by the provincial architect Foma Ivanovich Petondi in 1837. The relevance of the study is due to the lack of scientific research on the architects work during this period, which had tragic consequences for his work. The purpose of the study is to identify the details of the development of the Rodionovsky institute project and to reveal the problems associated with its construction. Research objectives: 1. To study the project of the Rodionovsy institute of the architect F.I. Petondi and the details of its development. 2. To recreate a three-dimensional model of the building of the Rodionovsky Institute in Kazan according to the initial project developed by architect F. I. Petondi. 3. To reveal for the first time the details of the court case against F.I. Petondi and other architects due to the identified errors in the construction of the architectural complex. Results. Based on the results of the study, archival documents of the project and materials of the court case were identified and studied for the first time, a volumetric-spatial model of the original project of the Rodionovsky Institute for Noble Maidens was developed. Conclusions. The significance of the work is in revealing previously unknown facts of the biography of the provincial architect F.I. Petondi and studying the architecture of the educational institution of the first half of the 19th century in Kazan. The results obtained can be used for the reconstruction of the Rodionovsky Institute for Noble Maidens, as well as for identifying the features of the creative style of the provincial architect F.I. Petondi.

Problem statement. There is a world practice in the field of tourism, when the centers to visit are preserved by religious or architectural-historical sites, united by unique natural landscapes, founded by pilgrims over the centuries. Modern pilgrims travel along historical routes that popularize the history and culture of the country. There are also similar historical routes in Russia which are associated with religious processions, but many of them are used episodically, at best once a year on the day of honoring a saint or a miraculous icon, and most are simply forgotten. The purpose of the study is to form new cultural tourist routes along historical roads in Zelenodolsk region of Tatarstan. The objectives of the study are to search for and analyze materials related to the description of religious processions in the territory of the former Kazan Province, now Tatarstan; Identification of the roads and paths along which pilgrims walked with a visit to historical settlements; suggestion of new routes. Results. The article reviews modern foreign experience of organizing tourist routes to historical and cultural places, the purpose of which is to popularize historical places in their natural landscape. The existing regulatory and legal documents and materials related to the organization of tourist routes in Russia are studied. In the archives of the Volga-Kama Reserve cartographic materials were found, which contain valuable data on the location of rural settlements along old roads and tracts; a new cultural and tourist route has been proposed on the territory of the Volga-Kama Nature Reserve. Conclusions. The study of the historical experience of road links and the location of rural settlements in Zelenodolsk region of the Republic of Tatarstan on the basis of old cartographic materials made it possible to identify the main elements of the conceptual landscape space, which can become the basis for the creation of tourist routes.

Religious buildings at hospitals began to appear simultaneously with the beginning of the construction of hospitals. The study of these facilities is relevant, since this layer of architectural heritage has not been sufficiently studied to date. The subject of the study is the spatial planning structure of religious buildings, such as house churches, chapels and churches at hospitals in large cities of the Russian Empire of the pre-revolutionary period. The research methodology includes the study of historical and archival documents, publications by Russian and foreign authors, generalization and systematization of information on the facilities under consideration, as well as the performance of the comparative analysis of spatial planning and stylistic solutions. The purpose of the work is to identify the architectural and planning features of religious buildings at hospitals in large cities of Russia, as well as to determine the prerequisites for their transformation in the context of time. The research objectives are to study the location of chapels and churches in the structure of hospitals and hospital complexes in large cities of Russia, including Kazan; to compare architectural, planning and stylistic solutions of the churches and chapels under consideration, and to identify their features. Research results: The characteristic methods of placing churches in the structure of hospital buildings and their complexes have been identified. The systematization of religious sites at hospitals and their features in terms of architectural, planning and stylistic solutions in the late 18th - early 20th centuries has been carried out. The importance for the architectural and construction industry consists in studying a previously unresolved problem, in identifying architectural and planning features of religious buildings on the territory of hospital complexes of the period under consideration.

Problem statement. In most historical cities of Russia, residential buildings constructed in the second half of the 19th – early 20th centuries are currently preserved. At the same time, historical buildings are complemented by modern facilities, often due to the loss of historical heritage sites or their location near them. With the proper development of urban planning space, the historical and modern architectural environment are in symbiosis and complement each other, but sometimes the task of preserving cultural heritage sites is very acute. This article examines the problem of formation, preservation and adaptation of the historical heritage of Kazan, in particular, the urban merchant estate of the late nineteenth century. Such estates at the end of XVIII - XIX centuries were a common type of residential development in many cities of the country. The relevance of the study lies in the fact that scientific historical and architectural research is required to assess the significance of this type of housing. In addition, many estates are currently in disrepair or partially used, and are not fully integrated into the architectural and urban planning sphere of the city. The purpose of the study is to examine the architectural and urban development and identify methods of preserving the urban estate of a large Russian city using the example of the Chernoyarov estate in Kazan. The objectives of the study are to determine the stages of formation of the urban estate, to propose an option for adapting the former estate taking into account modern conditions and needs. The results. Previously unpublished archival materials on the topic under study are introduced into scientific use. A comprehensive scientific study made it possible to establish the periodization and features of the formation of an urban estate. Conclusions. The Chernoyarov estate is a striking example of a merchant urban estate, reflecting the general development process in Russian cities of this type of residential development during the period under review. The main buildings of the former estate have been preserved: the main house and two outbuildings, the historical boundaries of the household have been changed. The construction of the hotel complex will preserve the historical integrity of the household and the original residential function. Solving these problems is important for the preservation and sustainable development of the historical and architectural environment of Kazan and other Russian cities.

Design of public and administrative buildings of complex architectural shape leads to the fact that the configurations of heating, ventilation and air conditioning systems become more branched with a large number of shaped elements installed in close proximity to each other.

the study of dynamics of the spread of hazardous fire factors and gas environment parameters on the fire floor is an important task for selecting the characteristics and location of smoke control system elements, as well as for substantiating regulatory requirements to them. The purpose of the study is to calculate the justification for technical solutions on fire safety in the corridor adjacent to the room with a fire load. To achieve this goal, the following tasks are performed: to review existing studies; to determine numerically the distribution of the main air parameters in the corridor adjacent to the room with the source of fire; to select the optimal location of the smoke collection device. Results. A fire was simulated with various options for the location of the exhaust opening for removing combustion products and the supply opening for compensating for the volumes of removed combustion products, using the PyroSim software package. Isofields of temperature distribution and smoke layer density on the fire floor are shown. The comparison of the simulated options for the relative location of the openings made it possible to select the most optimal option for evacuating people along a rectilinear corridor. Conclusions. The results obtained will make it possible to create the most favourable conditions for the evacuation of people from high occupancy buildings.

Problem statement. Due to increasing regulatory requirements for soils in the working layer of highway subgrades, the use of soil stabilization technology in road construction is expanding. However, the production of the main binders (lime, Portland cement) used in this technology is characterized by excessive consumption of energy and resources, as well as negative impact on the environment. It is relevant to develop technologies for stabilizing and strengthening soils using steel production waste, developed on the basis of alkaline modification as a binder. The purpose of the work is to develop a geopolymer binder based on steel production waste for road construction. To achieve the goal, the following tasks were solved: study of the influence of sodium and potassium alkalis on the strength properties of geopolymer materials using binders based on steel production waste; determination of the optimal content of potassium and sodium alkalis for waste activation; study of the influence of hardening time on the strength properties of geopolymer materials. Results. It has been established that the activation of steel production waste with sodium hydroxide affects the maximum increase in strength by 3.5 times at an optimal ratio of 96/4 binder/activator, due to the creation under aggressive conditions of highly alkaline synthesis of gel-like products N-A-S-H, N-S-H, K-A-S-H with the binding characteristics of a three-dimensional frame. The results obtained are a prerequisite for further research of geopolymer binders, including in the composition of clay soils for road construction Conclusions: The significance for the road construction industry lies in increasing the technical and economic efficiency of highway construction through the search for and development of new environmentally friendly, economical types of clinker-free binders, especially based on the recycling of industrial waste.

Problem statement. The world practice of designing the urban road network and evaluating the quality of service of its elements shows the need to take into account the opinions of all road users. The relevance of the study is to take into account the influence of pedestrian traffic on the traffic flows of unsignalized urban street junctions. The purpose of the study is to determine the parameters of traffic on the elements of the urban street and road network. The objectives of the study include the development of research methods (methods, selection of objects and conditions of observation) and the determination of the main actual parameters of traffic flows, which will determine the capacity and quality of service of unsignalized junctions, taking into account pedestrian traffic. The traffic intensity along the lanes, the intervals between cars when leaving the queue from secondary directions, and boundary intervals in the main stream are selected as parameters. Results. Based on the measurement results, a summary statistical analysis of the selected parameters was carried out. In the future, it is planned to conduct similar studies of traffic flow parameters in Vladikavkaz as a medium-sized city for a comprehensive assessment of traffic flow parameters in Russia.

Problem statement. The road construction industry is in dire need of introducing cheaper and more efficient road construction materials that will improve the quality of road pavement, increase its service life, which in turn will reduce the cost of road maintenance. The use of manufacturing wastes for the production of road construction materials can help reduce the cost of road construction materials, simultaneously solving the problem of environmental pollution. The paper studies the effect of stabilizing additives on the physical and mechanical properties of loam. The objective of the work is to assess the effect of active mineral additives on the physical and mechanical properties of soil. To achieve this objective, the following tasks are solved: soil samples are selected and tested for compliance with regulatory requirements; the characteristics of "Minplast" mineral additive obtained on the basis of metallurgical waste and lime, which will be used as soil stabilizers, are determined; the physical and mechanical characteristics of the stabilized soil, as well as the bearing capacity index and the California bearing ratio, are assessed. Results. Modification of soil with a mineral additive increases its bearing capacity index by 1.5 times. The California bearing ratio increases by 20%. Introduction of "Minplast" mineral additive into the soil, in the amount of 2%, allows increasing the density and elastic modulus. In addition, a significant increase in the angle of internal friction is observed. Conclusions. The use of "Minplast" active mineral additive has significantly improved physical and mechanical characteristics of the soil. Low cost, compared to other mineral binders used as stabilizing additives, makes its use very promising.

Problem statement. There is currently no single methodology in the Russian Federation that allows assessing the quality of transport services for transit and pedestrian traffic. Such a methodology is necessary to reasonably determine the demand for travel, which will allow for the selection of the most effective measures for the development of the transport system. The purpose of the work is to study the criteria for the quality of services when traveling on foot and on transit. The objectives of the study are: to create a method for assessing the conditions of pedestrian traffic and traffic on transit for consideration in the design of the road network. Results. The paper presents the results of research on the characteristics of pedestrian traffic and transit. Based on the results of a sociological survey, criteria for assessing the quality of services were determined. A model for assessing the level of convenience of movement is proposed. A comparative analysis of the obtained results is carried out. Conclusions. The application of a multifactorial model for determining the level of convenience of pedestrians and transit will more fully reflect the perception of users of their traffic conditions, which will allow a reasonable approach to assessing the quality of services on the urban road network.

Problem statement One of the relevant areas for improving the technical and economic efficiency of strengthened soil technology in road construction is the application of the integrated modification method. However, for the design of road pavements, there is insufficient data on systematic scientific and practical results on the effect of complex modification on the levels of design characteristics of road clothes layers constructed using strengthened soil technology, the physical, mechanical and operational characteristics of which exceed these indicators for layers without modification. The aim of the work is to study the effect of complex modification on the design characteristics of soil-cement layers of road pavements and design variants of road clothing structures with layers of complex modified soil-cement. In the course of the research, the following tasks were solved: to comprehensively modify soils strengthened with Portland cement and optimize their compositions for layers of road pavements; to establish the effect of complex modification on the calculated characteristics of layers of road pavements made of cement grunt; to design variants of road pavements structures with layers of complexly modified soil-cement. Results. It was found that the complex modification of modified soil-cement based on organosilicon hydrophobizer, polycarboxylate plasticizer and electrolyte increased the compressive strength by 2.6 times, the coefficient of frost resistance after 15 cycles of alternating freezing and thawing by 2.1 times, as well as the calculated characteristics of the layers of road clothing: flexural tensile strength by 2.8 times, modulus of elasticity by 62%, volume density by 2% and thermal conductivity coefficient by 3%. The increased characteristics make it possible to increase the grades of materials, as well as reduce the cement content in strengthened soils. The results obtained by the levels of design characteristics provided the possibility of designing road surface structures with layers of complex modified soil-cement. The use of a complex modification makes it possible to reduce the thickness of the layers while maintaining increased technical, operational characteristics and durability of road pavements. Conclusions. The significance of the study for the road construction industry is to obtain the values of the calculated characteristics of the layers of road pavements from complex modified soil-cement, providing the possibility of designing structures of road pavements with increased performance and durability, increasing the technical and economic efficiency of road construction.