Abstract Problem statement. The aim of this work is to study the additional settlement of slab-pile foundation under cyclic loading due to the compression of the reinforced concrete piles taking into account the redistribution of efforts between the reinforcement, concrete, piles and the surrounding soil. There are no research results on this issue in the literature. Results. We carried out theoretical studies, considered the redistribution of efforts between the main elements of the slab-pile foundation. The article considers the change in the stress-strain state of a compressed reinforced concrete element due to the appearance of deformations of concrete and reinforcement vibrocreep in coherent conditions. Based on the research, we proposed the equation of changes in stresses and constrained deformations of concrete and reinforced concrete pile reinforcement under cyclic loading to develop the method for calculating the settlement of a slab-pile foundation. Conclusions. The significance of the results for the construction industry is that for the first time the proposed method allows us to estimate the settlements of the slab-pile foundation due to compression of the pile under cyclic loading. It is a significant contribution to the theory of pile foundations calculation and provides concrete saving of up to 15 % compared to the standard method.

Problem statement. The aim of the work is to undertake theoretical studies of the fatigue strength of normal sections of reinforced concrete bending elements under stationary and non-stationary modes of cyclic loading, taking into account the continuous change in the state and endurance limits of materials. For the development of calculation methods, at present, in this formulation, research results are not enough. Results. The authors carried out theoretical studies of changes in the stress-strain state of normal sections of reinforced concrete bending elements under stationary and non-stationary modes of repeated cyclic loading. The research showed that, regardless of the loading mode, there is a change in the stresses and stress cycle asymmetry coefficients in the concrete of the compressed zone and the longitudinal stretched reinforcement. Based on the results of the performed studies, we developed a method for evaluating the endurance of normal cross-sections of reinforced concrete bending elements and analytical equations to describe the changes in stresses and stress cycle asymmetry coefficients in the concrete of the compressed zone and stretched reinforcement of normal cross-section. Conclusions. The significance of the result for the construction industry lies in the fact that the developed method allows for an adequate and accurate assessment of the stress-strain state and endurance of normal sections, which is a significant contribution to the theory of design of structures under the action of cyclic loads. It also provides economy of concrete and rebar up to 15 % compared to existing calculation methods.

Problem statement. The main purpose of the research is to determine the deformative and adhesion properties of fluoroanhydrite compositions, to study the effect of polycarboxylate ethers on the shrinkage characteristics of the compositions during hardening and creep under load. The relevance of the study is associated with the need to increase the use of man-made materials replacing traditional binders based on Portland cement, which contributes to the improvement of the environmental situation in the storage sites of man-made waste and a significant reduction in the cost of the finished product based on fluoroanhydrite. Results. The main results of the study are to determine the shrinkage during hardening and creep under load of fluoroanhydrite compositions; determining the effect of the polycarboxylate plasticizer on their deformation properties; determination of the physical and technical characteristics of the developed formulations. It is shown that the introduction of a polycarboxylate plasticizer improves the physicomechanical and deformative properties of the developed compositions: increasing the strength to 42,5 MPa and 17,5 MPa, reducing the shrinkage deformations of the composition by 10 times, increasing the water resistance of materials by 28 % due to the compaction of the structure. Conclusions. The significance of the results for construction industry consists in the development of non-shrinking compositions for flooring based on fluoroanhydrite binder, which can be used as a heat-insulating layer and a self-leveling fast-setting screed.

Problem statement. The purpose of the article was to study the structure of new electrochromic building materials, including the core (NP)3, viologen units, and terminal phosphonate groups, by recording IR and Raman spectra with subsequent quantum-chemical calculations. The possibilities of the practical application of electrochromic building materials have not yet been fully explored. Therefore, the study of the properties of molecular stars and the establishment of their relationship with the structure of the molecules are important. Results. The main results of the research are that the structure and vibrational spectra of new electrochromic building materials have been studied. The main regularities in the structure of molecular stars have been established. Geometric optimization and calculation of spectra were carried out for G3 in the framework of DFT. It turned out that G3 has an almost flat core and repeating hydrazone units. Interpretation of the IR and Raman spectra of the molecule has been carried out. The similarity of the vibrational spectra of stars of different generations testifies to the similarity of their molecular structure. For the first time, using IR and Raman differential spectroscopy the effects of the influence of the electronic environment on the frequencies and intensities of the bands have been discovered. Conclusions. The value of the work for construction lies in the fact that new building electrochromic materials have been synthesized and studied, which are used to control the passage of light through windows. The spectral properties of molecular stars (the intensity and width of the IR and Raman bands), determined by the ratio of terminal groups and repeating units, differ most strongly for the first three to four generations of phosphororganic stars. In order to interpret the vibrational spectra of molecular stars, it is necessary to carry out calculations of model molecules representing fragments of stellar molecules.

Problem statement. The purpose of the study is to develop a mathematical model of the plasticity of a fine-grained concrete mixture, which allows calculating the ultimate tensile strength of the mixture of known composition. Results. The main results of the study are obtaining a mathematical model of the plasticity of the concrete mixture, which establishes the dependence of the ultimate tensile strength on the main factors and demonstrates good statistical indicators, namely: the correlation coefficient is 0,997; the average approximation error is 5,7 %. Conclusions. The significance of the results for the construction industry consists in obtaining a mathematical model that allows calculating the ultimate tensile strength of a concrete mixture of known composition without resorting to testing, which can be used in designing the composition of a concrete mixture in order to ensure given plasticity.

Problem statement. A large amount of energy in ventilation systems is spent on overcoming resistance in duct fitting elements due to vortex formation. Elimination of vortex formation is possible by shaping along with the outlines of vortex zones and most efficiently carried out by numerical modelling. The aim of the study is a validation of the numerical model, which is carried out by comparing the obtained numerical results with experimental or analytical data, both in resistance and in the outlines of vortex zones when solving a test problem. Results. The article presents the results of setting a numerical model of airflow in the exhaust and supply symmetrical ventilation tee, by comparing the obtained results with the data of other researchers and our experiment. The values of the local drag coefficients and the outlines of vortex zones are determined for a different combination of the most universal models of turbulence and methods of near-wall modelling that are used in modelling flows in channels. The closest results are shown by the combination of the «standard» k-? model with the «enhanced wall treatments». Conclusions. The developed computer models of the supply and exhaust tee further will be used to numerically determine the local drag coefficient and the outlines of vortex zones for the entire range of variation of the ratio of airflow rates flowing through the side channel to the flow rate in the main channel. The resulting outlines of the vortex zones will be used to develop the energy-efficient shaped tees. Usage of these improved duct fittings will reduce the energy consumption of ventilation systems of buildings and facilities.

Problem statement. When developing ventilation systems, the main difficulty lies in determining the resistance of shaped parts connected in a combination of two or more elements. If two consecutive 90° elbows are located close, a Z-shaped configuration of the unit is possible. The hydraulic resistance of such a node is not equal to the sum of the resistances of the individual components and largely depends on the distance between them. To conduct their modelling in a previously unexplored three-dimensional setting is of interest. The purpose of the research is to conduct numerical studies using the computational fluid dynamics complex AnsysFluent to select the most optimal structure of the computational grid, parameters of the numerical scheme, configure the turbulence model options, control the convergence process of the solution for the problems of airflow in a rectangular duct with a shaped element in the form of a «sharp» Z-shaped elbow. Results. As a result of checking the non-stationary formulation of the problem, it is showed that the difference from the known experimental values of the local resistance coefficient is about 5-20 %, for the stationary formulation – 1?5 %. As a model of turbulence, the «standard» k-? model of turbulence with «enhanced wall treatment» is proved to be suitable. For boundary conditions, the choice of a uniform and developed velocity profile at the input boundary, as well as setting the turbulence intensity and relative turbulent viscosity instead of kinetic energy and dissipation, leads to the same result – the difference between the local resistance coefficient and the reference data is no more than 5-10 %. Conclusions. The significance of the results for the construction industry is in the development of a «numerical scheme» of the solution for studies of flows in channels with complex units of shaped elements, which allows to determine the shape of the vortex zones and to develop aerodynamically improved designs of such shaped elements of ventilation systems.

Problem statement. The purpose of the research is the study of the origin and development of the polycentric system in the city of Naberezhnye Chelny at the end of the XX century, the emergence and consolidation of new job opportunities and their impact on the development of services in the area, analysis of the causes of unplanned development of the city of Naberezhnye Chelny. Results. The main result of the study is the identification of the reasons for the formation of the spontaneous emergence of the polycentric system in the city of Naberezhnye Chelny, which arose as a result of the emergence of spontaneous unorganized trade jobs. Conclusions. The significance of the results for architecture and urban planning is that the identified reasons for the unplanned development of services in a particular area are of practical importance and can be considered in real urban planning practice aimed at creating the General plan of the city of Naberezhnye Chelny and in further reorganization of polycentric maintenance system of Kama agglomeration.

Problem statement. The purpose of the study is to identify the prerequisites for the development of recreational and tourist destinations in the Republic of Sakha (Yakutia), to develop urban planning recommendations for the formation of recreational and tourist clusters and the implementation of design solutions for the development of tourist infrastructure in the Republic of Sakha (Yakutia). Results. The key findings of the study are the following. We carried out a comprehensive analysis of the recreational and tourist resources of the territory of the Republic of Sakha (Yakutia), revealed problems and limitations in the development of tourism, identified the boundaries of the recreational and tourist clusters and the specificity of tourism and organization of tourism infrastructure in clustered areas. Conclusions. The significance of the results for architecture and urban planning is that authors identified the boundaries and dislocation of recreational and tourist clusters, determined functional and planning features and developed a cluster typology.

Problem statement. The study aims to identify the conceptual principles of the architectural formation for residential complexes. Current trends in the formation of a contemporary residential complex demonstrate the need for it to be not only comfortable and affordable for living but also to be a kind of complex for space-person, person-person interconnections. Based on this key principle, current paper describes the space-planning solutions used in creating a model of a contemporary residential complex and also highlights the factors that affect them. Soviet architects were among the first ones to propose the concept of a new type of dwelling with developed spaces for communication between residents at the beginning of the 20th century. Their ideas are still relevant nowadays. Results. Based on the studies, analysis of various residential complexes, both in Russia and abroad, the most relevant space-planning solutions have been identified to allow creating a special environment for living activity within the complex. One of these solutions is the development of communicative spaces using covered walkways between residential blocks. Conclusions. The significance of the results obtained for architecture consists in the theoretical understanding of the Russian and foreign experience in the formation of modern residential complexes. The analysis allows us to identify several space-planning solutions of modern residential complexes, which involve the creation of a special living environment within the complex. The characteristic elements of such space-planning solutions are covered passages between residential buildings for the formation of communicative spaces in them.

Problem statement. The purpose of the study is to establish the level of effectiveness, expediency and necessity of comprehensive protection and rescue of people in terrorist acts, based upon the accumulated world experience, intensive development of modern infrastructure and increased regulatory requirements for the protection of people and reliable protection of unique buildings and structures. Results. The main results of the study are that a scientifically based and practically tested system of comprehensive protection of unique buildings and structures in case of terrorist acts will significantly increase the level of normal functioning of unique structures and ensure the safety of the population. Conclusions. We developed comprehensive protection of unique buildings and structures in terrorist acts. The significance of the results for urban and architectural and construction sectors represents the improvement of the degree of urban areas protection from terrorist acts at unique structures; life safety provision for people in the zones of protection from external influences; the use of special protective volumetric block (SPVB) for salvation and preservation of people who had not managed to leave the area of collapse of the building; the development and provision of conditions for preservation and maintenance of environmental protection requirements with constantly functioning infrastructure of the city.

Problem statement. This article examines a range of problems associated with the search for optimal solutions for the architectural and spatial organization of children’s camps with a creative bias, in accordance with modern trends in the growth of the role of applied and environmental education in the educational process. The main goal of this study is to identify the features of the architectural and planning structure of children’s health camps with a creative bias in the context of the historical development of children’s summer camps in Russia and abroad in accordance with modern principles of their functioning. The research tasks are: - identifying the features of the functioning of modern children’s camps with a creative bias; - comparative analysis of architectural and planning structures of Russian and foreign children’s health camps; - development of recommendations for the design of children’s health camps with a creative bias. Results. The method of comparative analysis of the architectural and planning structure of existing Russian children’s health camps with similar foreign projects of summer architectural schools revealed several characteristic features of the organization of creative open spaces for children’s health camps, which are recommended to take into account for creating architectural and planning design of their territories. Conclusions. The significance of the results obtained for architecture includes identifying several characteristic features of the organization of creative open spaces for children’s health camps, which must be taken into account in the architectural and planning design of their territories.

Problem statement. The aim of the research is to study the Kazan period in the creative biography of the architect S.V. Bechko-Druzin. Results. As a result of the study, the Kazan period in the creative biography of S.V. Bechko-Druzin was determined, the key stages of the architects life were highlighted, the main structures of the author realized in Kazan were architecturally described. Conclusions.The significance of the results obtained for architecture lies in obtaining new knowledge about the creative path of the architect S.V. Bechko-Druzin. The research materials can become the basis for further research of the architects work in his Kazan period, as well as other periods associated with the cities and districts of the Kazan province. The material also contributes to the study of the origins of the formation of architectural and construction education in Kazan.