Thermophysical aspects of reconstruction of cold roof spaces

The results of theoretical studies of thermal modernization of cold roof floor. The designs of overlap of long-life roofs of public buildings were considered. Overlap of these buildings are made by wooden or concrete beams and made of concrete slabs with upward edges. The problems of thermal modernization of these designs are consideration of the impact of heat-conducting inclusions on the resistance to heat. The heat-conducting inclusions of constructions are beams and vertical edges of the slabs. The results of calculations of the temperature fields were used for the analysis. The research was carried for the two temperature zones which Ukraine’s territory is divided into. The analysis of thermal protection level of structures overlap was made. The magnitude of the impact of heat-conducting inclusions on resistance to heat after thermal modernization of cold roof floor was observed. The analysis showed that the thermal protection properties of structures less than standard, therefore the insulation of areas with heat-conducting inclusions is required. The options of insulation of these areas were considered. The optimal insulation options with the least amount of additional insulation over the heat conductive areas were selected

МІЦНІСТЬ ТА ДЕФОРМАТИВНІСТЬ СТАЛЕБЕТОННИХ КОНСТРУКЦІЙ СКЛАДЕНОГО ПРЯМОКУТНОГО ПЕРЕРІЗУ НА ЛЕГКИХ БЕТОНАХ

A critical analysis of recent studies on the usage and design of lightweight steel structures has been carried out. The unresolved issue remains the definition of compatible work of light concrete and the profiles in composite closed structures working on compression. The corresponding data is not enough to provide clear recommendations for the design, modeling and actual operation of such structures. Therefore, the obtaining of new data, which allow to describe and correct as much as possible precisely the well-known mathematical models of the work of structures, to specify more accurate the boundary conditions is a current issue nowadays.The data presented in this article have an experimental substantiation, which will further influence the creation of the correct geometric model of steel structure on light concrete. The selection of effective materials for the construction of a lightweight steel structure has been analyzed and performed. The physical and mechanical characteristics of the used materials are determined. The results of the experimental studies of strength and deformability of steel concrete structures of composite rectangular cross section on light polystyrene concrete are given. The experimental researches were carried out in three stages: the consideration of constructions of open section profiles, closed composite section and the formation of spatial steel structure - pylon. The efficiency of gradual reinforcement of composite profiles by polystyrene concrete has been determined. Characteristics of the destruction of each of the above listed composite steel and steel concrete structures are described. Photofixation of the destruction of steel concrete structures was carried out.The effectiveness of using this type of structures is confirmed by the results of the experimental studies. Taking into account the absence of domestic and foreign normative base as for the design of lightweight steel structures, the collection of information, the conduct of field experiments, the standardization and synthesis of already existing works are the perspectives for the development and improvement of this type structures.Проведен анализ и экспериментальное обоснование создания корректной геометрической модели сталебетонной конструкции. Проанализирован и выполнен подбор эффективных материалов для образования эффективного сечения легкой сталебетонной конструкции. Определены физико-механические характеристики использованных материалов. Приведены результаты экспериментальных исследований прочности и деформативности сталебетонных конструкций составного прямоугольного сечения на легком полистиролбетоне. Проведен анализ эффективности использования данного типа конструкций с последующими рекомендациями по использованию в строительстве.Проведено аналіз та експериментальне обґрунтування створення коректної геометричної моделі сталебетонної конструкції. Проаналізовано та виконано підбір ефективних матеріалів для утворення ефективного перерізу легкої сталебетонної конструкції. Визначено фізико-механічні характеристики використаних матеріалів. Наведено результати експериментальних досліджень міцності та деформативності сталебетонних конструкцій складеного прямокутного перерізу на легкому полістиролбетоні. Проведено аналіз ефективності застосування даного типу конструкцій з подальшими рекомендаціями щодо використання у будівництві

Development and implementation of algorithms of building structure engineering calculations for shear fraction under pressing-through.

Development of calculating algorithms for designed and patented constructive solutions for beamless monolithic slab and concrete reinforced column connection in the form of software program is presented in this article. Also a mathematical model for the constructive solutions was created using finite elements method. A theoretical part of the research includes engineering technique for the connection nodes between monolithic concrete slab and reinforced concrete column in stress strain state. A technical goal is simplifying and reliability increasing of loading capacity of the junction and assembly work facilitation along with reducing building frame costs. To perform testing of connection nodes between monolithic reinforced concrete beamless non-bearing slab and reinforced concrete column for shear existing calculating algorithm was improved using the designed formula. A connection node for a shear along the column body calculation according to the technique was also implemented as a software program. A technique for calculating a connection node between monolithic beamless non-capital concrete reinforced slab and concrete reinforced columns was developed. Visual Basic for Applications was used to automate calculating of the connection nodes for shear. The research results have been implemented into practical design and calculation during extension of manufacturing building of Skvira confectionary shop in Skvira settlement

Influence of external and internal cooling at solidification on strength of brittle duralumin in compression

The causes of the occurrence and influence of inherent stresses, unevenly distributed across the cross section, on the strength of materials are analyzed. Methods of creating artificial distribution of inherent stresses with opposite signs in comparison with the usual distribution obtained with natural solidification of the material are given. The sequence of an experiment on cylindrical specimens made of epoxy resin and brittle silicate aluminum alloy in creating distributions of inherent stresses with opposite signs is described. The results of experimental tests of the influence of inherent stresses unevenly distributed across the cross section, on the strength of the epoxy resin and of the fragile silicate aluminum alloy with compression are given. Quantitative characteristics of the influence of unevenly distributed inherent stresses on the strength of materials under compression are obtained. The reasons of the influence of inherent stresses on the strength of materials under compression are analyzed and grounded

Influence of external and internal cooling at solidification on strength of brittle duralumin in compression

The causes of the occurrence and influence of inherent stresses, unevenly distributed across the cross section, on the strength of materials are analyzed. Methods of creating artificial distribution of inherent stresses with opposite signs in comparison with the usual distribution obtained with natural solidification of the material are given. The sequence of an experiment on cylindrical specimens made of epoxy resin and brittle silicate aluminum alloy in creating distributions of inherent stresses with opposite signs is described. The results of experimental tests of the influence of inherent stresses unevenly distributed across the cross section, on the strength of the epoxy resin and of the fragile silicate aluminum alloy with compression are given. Quantitative characteristics of the influence of unevenly distributed inherent stresses on the strength of materials under compression are obtained. The reasons of the influence of inherent stresses on the strength of materials under compression are analyzed and grounded

Development and implementation of algorithms of building structure engineering calculations for shear fraction under pressing-through.

Development of calculating algorithms for designed and patented constructive solutions for beamless monolithic slab and concrete reinforced column connection in the form of software program is presented in this article. Also a mathematical model for the constructive solutions was created using finite elements method. A theoretical part of the research includes engineering technique for the connection nodes between monolithic concrete slab and reinforced concrete column in stress strain state. A technical goal is simplifying and reliability increasing of loading capacity of the junction and assembly work facilitation along with reducing building frame costs. To perform testing of connection nodes between monolithic reinforced concrete beamless non-bearing slab and reinforced concrete column for shear existing calculating algorithm was improved using the designed formula. A connection node for a shear along the column body calculation according to the technique was also implemented as a software program. A technique for calculating a connection node between monolithic beamless non-capital concrete reinforced slab and concrete reinforced columns was developed. Visual Basic for Applications was used to automate calculating of the connection nodes for shear. The research results have been implemented into practical design and calculation during extension of manufacturing building of Skvira confectionary shop in Skvira settlement