The experience of operating PVC windows in areas with low winter outdoor temperatures has shown that they are subject to significant bending temperature deformations, which lead to a decrease in their performance. Nevertheless, these deformations are not taken into account in any way when designing PVC windows, which is due to the lack of an engineering methodology for calculating them for temperature loads. This article presents an engineering approach to the calculation of PVC window profiles temperature deformations. It is demonstrated on the example of a PVC window mullion with a reinforced steel core subjected to temperature bending in winter operating conditions. The calculation is performed in two ways: numerically analytical and simplified analytical. To verify the calculation method, a double-casement window was tested for temperature load in a climate chamber. Comparison of the calculation result with the test results showed a discrepancy of 10.6% (for numerical and analytical calculation) and 16.2% (for analytical calculation). The results of laboratory tests confirmed the assumption adopted in the calculation methodology: the calculation of the mullion temperature deformations when it is hinged to the frame can be carried out without taking into account the rigidity of the casements adjacent to the mullion, since the casements and the mullion are deformed under the influence of temperature together and do not transfer mechanical forces to each other.

The physical essence of resistance of concrete and reinforced concrete from dislocations, micro-cracks to macro-cracks and its experimental justification is investigated. For the "eight" structure of crystals of different materials (concrete and steel) a general model in the form of a sphere was developed. For it the summation of volume sectors, levels - radii from the matrix of sliding planes (including octahedral and pure shear) is written down. This uses an alternative to the theory of plasticity in the form of energy interpretation on the surface of the sphere and determining the integral of the mean square of the tangential stresses. It is important to obtain dislocations in the microcrack, angular and linear deformations, and displacements in a representative volume of the concrete cube. As the intensity increases, the deformation process proceeds already to the mainline cracks, where the double-concole elements of tension, compression, transverse shear and torsion (its internal parameters)are refined. Significant issues are the dilatation modulus and transverse coefficient, for which functions have been developed at the stages of the stress-strain state of concrete during the evolution of the transition from crack formation to main cracks. Concrete compression and tension diagrams for strain intensity or minimum pure shear use shear stresses. The fundamental difference of the stress diagram in the downward section is the use of the ultimate resistance of the concrete. Stress reduction in a material whose failure has a "tear-off" character is an unnatural phenomenon, and the limiting resistance of concrete at and reduction of prism strength at the i-th step is . The deformation pattern of concrete during the formation of earlier microcracks and then later main cracks is oriented along for compression or across the loading line for tensile force.

The existing methods for determining the wind load coefficients are analyzed in order to identify the features of the influence of the type of distribution on the forces from the impact of the wind on the structures of buildings and structures of a prismatic type with different proportions of the frontal surface. Reinforced concrete buildings with the first frequency of natural vibrations greater than the limit value were considered. The study was carried out on the basis of the study and analysis of the main provisions of regulatory documents regulating design and development activities in the Russian Federation, as well as relevant works of domestic and foreign scientists relevant to research in this area. The research method is structural-analytical analysis using the correlation dependences of the studied factors. Analytical dependences are given to determine the forces from the wind with various methods of assigning the coefficient of the pulsating wind load along the height of the building, taking into account the shape and proportions of the wind surface, as well as their graphical interpretation. The work is based on the provisions of domestic building codes and regulations and relevant information contained in other domestic and foreign sources and standards. It has been established that in buildings of a prismatic shape there are separate sections where the forces from the components of the wind load significantly depend not only on the proportions of the frontal surfaces, but also on the methods used to establish the distribution law of the coefficients. The conducted research indicates the ambiguity of the results obtained, allowing the possibility of exceeding or underloading structures or individual elements. The results of the work make it possible to correct calculations for establishing the values of wind loads for the considered types of buildings and height ranges and to predict for other objects with different parameters.

Increasing the strength properties of wooden structures is an important task. Wood can have many defects associated with the natural structure (defects) or obtained during operation (rotting, shrinkage, etc.). To increase the strength of wood and, consequently, the bearing capacity of structures based on it, both traditional methods (reinforcement with metal, concrete or reinforced concrete) and currently promising methods of modification with polymer compositions, including those with nanostructured filler, are used. In this work, a study was carried out to determine the compressive strength of modified wood samples along the fibers. Four different resins and two fillers were considered - carbon nanotubes and carboxylated carbon nanotubes, which were added to the binder in different percentages (from 0 to 1.1%). As a modification, the technology of impregnating a low-viscosity polymer composition into the wood body was applied using pulsed overpressure according to the 10-5-10-5-10 min mode. Modified specimens were tested under short-term loads until failure. The results of testing on samples determined the possibility of increasing the strength and deformability of a wooden structure modified with a resin-based polymer composition with the addition of a nanostructured filler.

The paper studies methods for obtaining dynamic characteristics (dynamic modulus of elasticity, loss coefficient) of structural materials, such as concretes and cement mortars, based on the results of experimental modal analysis. Closed expressions for determining the loss coefficient of mechanical vibrations are presented, obtained from solving differential equations of vibrations of single-mass systems, which are caused by vibrations of extended structures in the first forms. The procedure of modal analysis of short beams made of test samples of structural materials is presented. The procedure for calculating the natural frequencies of the first forms of vibration of beams is presented. Based on the solution of the equation, a formula is presented for determining the damping coefficients and the dynamic modulus of elasticity of the beam material.

The article describes algorithms for probabilistic evaluation of steel trusses’ reliability by the deflection criterion using p-boxes as models of random variables. The p-boxes are an area formed by the boundary cumulative distribution functions (CDFs). There is a real probability distribution function of a random variable inside the p-box area. Based on the presented approaches, it is possible to design trusses on a given reliability index or probability of non-failure. P-boxes as random variable models take into account aleatory and epistemological uncertainties at the same time. Such models are relevance for snow loads as one of the main factors affecting the stress-strain state of trusses. Information about the reliability level of steel trusses according to the deflection criterion is necessary for a system assessment of the reliability of a truss. An approach of structural reliability analysis is also proposed for existing trusses, where the ultimate deflection is limited by the condition of buckling of the selected truss bar.

The object of research is the corrosion process of destruction of concrete and reinforced concrete structures in aggressive media. The purpose of the investigation is to establish a set of relationships and ratio between the characteristics of this process and various external and internal factors that affect the growth of corrosion. To solve the tasks set on the basis of the obtained experimental data, the method of mathematical modeling of corrosion processes was applied. The theories of physical and chemical transformations and heat and mass transfer laws suggest that different stages of corrosion can be simulated by differential equations of interrelated heat and mass transfer with boundary conditions. They are defined by arbitrary functions of initial transfer potentials and nonlinear boundary conditions of all known types. The possibilities of developed physical and mathematical models of mass transfer in the processes of studying corrosion of various types are demonstrated. They allow to evaluate the concentration of the transported component throughout the thickness of the concrete structure and in the biofilm itself at any time, as well as the concentration of "free" calcium hydroxide in the liquid phase. As a result, it is succeeded to predict the durability and reliability of concrete structures with a minimum error. The proposed author's model of the destruction of cement concretes, taking into account the colmatation of pores and capillaries, ensures the adequacy of judgments about the kinetics of mass transfer processes during corrosion of the II type.

The study is aimed at the comprehensive modernization of outdated residential areas in the cities of the Republic of Kazakhstan. The content is focused on the study of methods of space-planning and functional-urban planning solutions, on the example of a residential area in the city of Saran. Due to the deterioration of engineering systems, finishing and insulation materials, residential buildings of the Soviet period have a low level of energy efficiency and comfort, do not meet modern requirements for the improvement and placement of infrastructure facilities. Measures are needed to increase the socialization and commercial attractiveness of development, which contributes to the sustainable development of urban and suburban areas, as well as satellite cities. The collection of information and technical documentation, questionnaires and surveys of residents are being carried out. The collected material is analyzed, based on the analysis, a conceptual solution is proposed. A 3-D model method of design and visualization is used. A conceptual volumetric-spatial solution for the modernization of a two-storey residential area is being developed. A set of measures is being taken to increase commercial and residential space, create a comfortable and safe space within the residential area, and increase the variety of public and private spaces.

In a paper, architectural styles, constructive solutions, information on the history of appearance of structural building materials are briefly set forth and the stages of passion of thin-walled space large-span erections are analyzed. Particular attention is given to establishment of the exact dates in the chronology of appearance of styles, constructive solutions, and in the dates of erection of the first shells of corresponding styles and their authors. Elicit reasons of destructions of some well-known space structures are described and the influence of these destructions and damages for the subsequent designing and building of analogous type is analyzed. It is adduced, in general, positive views of noted architects on the role of shell structures in industrial, public, and civil building at present time. On the basis of the manuscripts published in specialized editions, varieties of points of view of architects to designing space structures are characterized. It was shown that interest of designers and architects in designing of shells in the form of analytically non-given surfaces, polyhedrons, and hipped plate structures is intensively extending. At present, bar metal architecture obtained subsequent development and came to be competitor for reinforcement concrete. In the XXI century, steel net and structural shells are the main means of forming vanguard buildings. Now, architects and structural engineers have wide potential in the selection of form, building material, methods of strength analysis, constructive solutions, styles, and examples of application of large-span thin-walled shell structures. All conclusions of the present work are corroborated by the results of researches containing in 54 references.

Studies have shown that it is not recommended to introduce thinning materials of more than 10-15% into clay masses with a number of 12-15. The introduction of more than 15% of thinners into ceramic masses (charge) reduces the plasticity of the charge with subsequent deterioration of molding properties, and less than 15% does not improve the drying properties of raw bricks (semi-finished products). Taking into account the emerging problem associated with the reduction of clay materials with a plasticity number of more than 12-15, it is necessary to study and explore the possibilities of replacing such traditional clay materials with montmorillonite clays. Montmorillonite clays, added even in small quantities, significantly improve the molding properties of ceramic masses, in which non-plastic mineral components predominate. To obtain the wall material, montmorillonite clay was used as a clay binder, and "tails" of polymetallic ore enrichment were used as a thinner". To get a ceramic brick from montmorillonite clay without thinners prak.