Modern design of bended reinforced concrete constructions uses analytical methods of calculation involving deformative models, the main tool of which is the actual diagram of concrete state, which establishes the connection between its stressesband relative strains bin compressed and tensile zones of the cross-section. Currently, there is no a unified methodics of establishing such a diagram, and researchers obtain it by indirect methods that differ from each other. That is why the graph-analytical building and mathematical description of the functional dependence of the diagram of concrete state based on clearand accurate physical representations we consider as an important and urgent problem.The lackof a unifiedmethodics for obtaining a diagram of concrete state cast doubt the reliability of the results of the calculations carried out, does not allow to compare, explain and link into a unifiedwhole the many experimental and theoret-ical data accumulated by generations of researchers.In a number of scientific publications, an opinion is expressed that a diagram of concrete state can be obtained by simultaneous using of diagrams of concrete deforming under different force modes of short-term axial compression –«soft» and «rigid», testing standard concrete specimens to failure at a constant rate of stress and strains growth respectively. If the «soft» force mode without unnecessary difficulties can be realized on traditional hydraulic presses, the creation of «rigid» mode requires the manufacture of different from standard special presses or auxiliary devices, capable of taking efforts and unloading concrete after reaching the maximum of compressive stresses. The lack of a unified approach to obtaining diagrams of deforming under rigid-mode loadings leads to contradictory results.Insufficiently investigated in the general problem are the issues of theoretical justification, development and approbation of diagram of concrete rigid-mode deforming bb~, complex application of which simultaneously with the diagram of de-forming bb~in conditions of «soft»force mode will allow to obtain a reliable and convincing diagram of concrete state.The main purpose of the research is a graph-analytical building and mathematical description of the dependence bb~, based on clear and accurate physical representations, which experimental obtaining causes serious technical difficulties and eco-nomic costs, and the accuracy of measurements made and the reliability of the results obtained causes big doubts.The article develops the criteria to which the dependence bb~should correspond, based on modern ideas about the nature of strength and deforming and following from the essence of physical and mechanical processes in concrete; the ade-quate structure of the functional connection has been established; the boundary conditions have been drawn up and constant coefficients have been determined; a comparative analysis of the calculation results using the proposed dependence with the corresponding experimental data was performed.As a result, an easy-to-use and mathematical processing of an approximate function of the diagram of deforming is proposed, which reflects the dependence between stresses and strains of concrete under the «rigid» mode of homogeneous compression. Its simultaneous use with the previously obtained diagram for soft-mode loading makes it possible to graphically build and mathematically describe a stable and free from excessive influencing factors the diagram of concrete state, suitable for based on the deformative model of cross-sections of modern calculations of bended reinforced concrete constructions for all groups of limiting states and assessment of the heterogeneous stress-strain state of constructional cross-sections at any stage of loading up to fracture.

The aim of the research is formulated, which is the theoretical substantiation, development and testing of the concrete state diagram, suitable for use to calculations of the strength of bended reinforced concrete elements based on the deformational model, as well as for more complete assessment of non-uniform stress-strain state of the cross-sections of elements at all stages of their loading up to the destruction directly on the values of the relative strains of concrete and the corresponding stresses. In this paper, an analytical method of converting the parameters of reference concrete deforming diagrams, which are determined experimentally during standard tests of concrete prismatic specimens by short-term axial compression and tension up to the destruction in «soft» mode of loading, into parameters of simulated transformed diagrams, which correspond to the «rigid» mode of loading of concrete, is developed. The way of simultaneous application of analytical expressions for the specified defoming diagrams, which describe the operation of concrete in conditions of uniform compression, for transition to the state diagram, which displays the functional relationship between the stresses and strains of the concrete compressed zone in bended concrete and reinforced concrete elements, cross-sections of which operate in conditions of non-uniform stress state, is proposed. The results of testing the obtained mathematical model of the concrete state diagram during the calculation by different methodics of strength of the normal cross-sections of bendable reinforced concrete elements are presented. It has been determined that a promising direction for further experimental and theoretical research is the study of the application of the developed methodics of graphical building and mathematical descripting of concrete deforming diagrams under conditions of uniform and non-uniform compression to the calculation of concrete and reinforced concrete elements that are operated under the action of long-term and short-term low-cycle loadings.

Стаття розкриває стан сучасної наукової думки до питання розрахунку кількості пасажирів на авіаційному транспорті. Дослідження має оглядових характер, задачею якого є визначення й оцінка методів при вирішенні задач транспорту. Для досягнення поставленої задачі використано наукові публікації, які уключено до наукометричної бази Scopus. Відповідні наукові підходи до визначення параметрів пасажиропотоку на авіаційному транспорті досліджено у розділі частини обрання та використання методів для розрахунку відповідних параметрів. Висвітлено авторську думку до питання обґрунтування вибору використаного авторами методу та оцінку адекватності запропонованих авторами методів. В роботі було використано метод системного аналізу при вирішенні поставленої задачі із проведення дослідження стану сучасної наукової думки про обрання методів розрахунку пасажиропотоку на авіаційному виді транспорту.

The capital building field is constantly updating the tasks: to reduce material consumption, cost and complexity of building, the mass of buildings and structures; significantly improve thermal protection; to increase the level of industrialization of building and factory readiness of prefabricated constructions; to improve the architectural and operational qualities of buildings and structures. Practical realization of the set tasks entails the the necessity to expand the use effective kinds of building materials and constructions, improving their properties. The field of effective three-layer constructions in civil, industrial and agricultural building is wide and multifaceted, as it covers almost all constructive elements of buildings, the solution of which depends on the functional requirements imposed on buildings and structures, local climatic and geological conditions, availability of building materials, level of development industrial base, etc. Already behind the idea itself of layered reinforced concrete constructiones have significant advantages: 1) the ability to select the materials of the layers taking into account the effective use of their main functional qualities; 2) reducing the cost and outlay of cement; 3) weight reduction of separate constructions and buildings and/or structures as a whole; 4) reducing heat consumption and increasing heat transfer resistance without thickening the construction; 5) improving the temperature-humidity regime in the room, etc. The purpose of this article is to perform a brief overview of research, proposals for standardization of design developments conducted during the most active implementation in Eastern European building practice of three-layer reinforced concrete constructions for fencing by the heat, air and waterproofing properties, strength, deformations and crack resistance, as well as their manufacturing technology. The article takes into account the results of research, field observations, materials for the development of new proposals, accumulated in many research and design departments of Eastern Europe in the period from the late 60’s to mid-80’s of the 20th century (Research Institute of Building Constructions, Kyiv Zonal Research Institute of Experimental Design, Ukrainian Research and Design Institute of Civil Rural Construction (Ukraine); Central Research Institute of Building Constructions named after V.A. Kucherenko, All-Union Research Institute of Fire Safety, All-Union Scientific Research Institute of Reinforced Concrete, Central Research and Design Institute of Residential and Public Buildings, Central Research and Design and Experimental Institute of Industrial Buildings and Structures, Central Research Institute of Experimental Design of Commercial and Domestic Buildings and Tourist Complexes (Russia), etc.).