The article is devoted to the development of calculating methods of the crack resistance and rigidity of reinforced concrete composite constructions under the action torsion with bending. It is based on proposed classification of discrete cracks and working assumptions, which allow to adjust the rigidity parameters noticeably. It is proposed a new classification of spatial base cracks in reinforced concrete composite constructions which based on an in-depth study of nature of the crack formation. This classification is based on the geometric, force (deformational) and interspersed concentration of the stress-strain state with the corresponding sources-concentrators. The double console models have been constructed to analyze the resistance along the path of crack and along the seam between different classes of concrete; models of level crack appearance, which allows to search for the distances between the cracks and the width of their opening and to display the multilevel crack development process. The block calculation model of the first level with a complete picture of the cracks and their projections to the horizontal axis in the form of a function of many variables is proposed; the stress-strain state of the calculated cross-sections was determined with the help of the software complex "Lira-CAD". This model takes into account the effect of disturbing the continuity of concrete, the incompatibility of the deformations of concrete and reinforcement and intermediate perturbation in the joint between the concrete. The width of the crack opening is analyzed along the entire profile of the crack; the change in the distance between the cracks l _crc and the change in crack length h _crc is taken into account as the load increases (with verification of the multilevel formation process) under various static schemes, reinforcement characteristics, prestressing, various classes of concrete. The algorithm of calculation provides the construction of a complete picture of crack development and their opening, according to the proposed classification; the determination of the distance between the cracks and the width of their opening, as well as the projection of contiguous cracks on the horizontal axis.

The paper contains the results of testing of compressive members reinforced longitudinally and transversally with steel and GFRP reinforcement. The spacing of transverse reinforcement (stirrups) and longitudinal reinforcement ratio varied in the specimens. The stress-strain, stress-Poisson’s ration, stress-volumetric strain relationships for tested specimens are given. It was observed that the appearance of cracks occurred with loading 90% of total. By the results of testing investigated that with the decreasing of spacing of transverse reinforcement the strength of specimens increased. It can be concluded that by using small spacing of transverse reinforcement transverse strains and Poisson’s ratio decreasing, while modulus of elasticity increasing.

An algorithm has been developed for calculating channel thin-walled bar frame systems using the fi-nite elements method. The research performed based on plate finite elements showed that the assumption of approximate equality for bimoments in bar connection nodes with this type of cross-sections is generally un-acceptable. An explanation of this phenomenon is proposed that takes into account the features of the trans-fer of the internal forces in the connection joints of thin-walled bars. An iteration scheme was suggested to consider bimoment leaps at bar joints. The sufficiently high accuracy of the presented methodology was illus-trated with the examples of calculating thin-walled structures consisting of two and three channel thin-walled bars. The obtained results will make it possible to increase the accuracy of calculations of load-bearing systems formed by channel structural elements in case of using the rod models.

The technique of experimental studies of deformation of monolithic reinforced concrete building under under accidental actions is presented. The main task of the research was the task of experimental verification of the accepted criteria for the destruction of the elements of the reinforced concrete frame system of a monolithic multi-storey building in out-of-state conditions, after the accidental actions in the form of a sudden removal of one of the columns, numerically using the decomposition method and the LS Dyna software package; The calculated values of the maximum dynamic deformations of compressed concrete, reinforcement and displacement of the elements of the considered structural system on the first half-wave of oscillations are determined, and the accepted variants of reinforcement of experimental structures, accidental loading techniques and schemes of installation of measuring instruments, a list of the main experimental parameters subject to experimental verification are substantiated.

Since 1964, the natural illumination of the earth's surface has been monitored at the Meteorological Observatory of the Lomonosov’s Moscow State University, since 2012 - the illumination of four differently oriented vertical surfaces. This is the longest series of continuous recording of natural light in the world, and for the territory of Russia it is the only one. Based on these observations, the temporal variability of illumination under a clear sky and at average cloudy conditions were analyzed. The estimation of impact of various climatic factors on theillumination was done: solar elevation as the main astronomical factor causing the periodic change in earth’s surface illumination, cloudiness as a factor leading to disruption of cyclicity, surface albedo as a seasonally acting factor. The correlations between illumination of the horizontal surface and each of the vertical surfaces have been obtained. The results of monitoring the illumination can be used to assess the light conditions of premises for the mutual coordination of the norms of artificial and natural lighting during the day.

The purpose of this work is to study the formation of the structural-functional planning and compositional structures of cities under the influence of internal and external factors. Interconnected decision composite problems with General problems of development and territorial growth of the city remains the basis for a coherent structural and functional urban formation Wednesday for creating comfortable Wednesday of vital functions modern society. In this paper, based on the example of Voronezh forming planning structure of the metropolis, and the urban problems have been identified in the course of the historical development of the city. On the basis of the results, a concept of a new project of spatial development of the city. The pace and development of compositional design, structural-functional frame of the city should be guided by the need to preserve its integrity as a complex multilevel system, i.e., the direction and pace forms and principles of his structure. Gradually analyzing historical urban schemes and identifying problems in the formation of the space of different hierarchical levels, it is possible to create a new project proposal that meets the needs of modern society and the short term development.

The practice of designing sound-insulating liners of air ducts shows that in some cases the actual sound insulation of air ducts made of porous materials, and in particular of Flex-ST material, may differ from the calculated values. The article presents the results of a comparative analysis of the measured and calculated values of additional soundproofing of air ducts due to the installation of the cladding from the porous sound-insulating material Flex-ST. Comparison of experimental and theoretical studies of the acoustic efficiency of airway linings from sound-insulating porous material showed good agreement between the measured and calculated data in determining the sound insulation in the high-frequency region. In this frequency range, airtight lining with a porous material of the Flex-ST type reduces the acoustic power of noise emission from the duct by 25 dB or more. At low frequencies, phenomena of interference of sound waves are manifested. As a result, local dips or increased sound insulation are observed. Based on the results obtained, suggestions are given on the practical calculation of sound insulation of air ducts when they are faced with porous materials.

Heat flow through the fiberglass products is the sum of four summands: the conductive flow through the gas in the pores of material, the conductive flow through the matrix of material, radiation flow through the gas in the pores of material and convection flow through the gas in the pores of material. The calculations of the general and radiation heat flows for the fiberglass articles made for the fused quartz by the density from 10 to 125 of kg/m ³ in the range of temperature from -20 to +25 ^о С are executed. The calculations permit to make the following conclusions: - the portion of radiation flow in the general heat flow is essential only with the low densities of material and decreases with an increase of its density, most rapidly portion decreases by the low values of material density; - the portion radiation flow in the general heat flow it decreases with the decrease of temperature, but even at a temperature of +25 ^о С it is essential only to the low densities of material .

To design environmental protection from the noise effect of large-sized gas-air channels of power objects, it is necessary to have methods for calculating the noise inside channels, objectively assessing the processes of formation and propagation of sound energy in them. The article considers the possibility of applying for this purpose the method of the source function realizing the statistical energy model of the reflected sound field in closed air volumes. The results of an experimental estimate of the accuracy of the source function method are shown and the limits of its application for the calculation of noise in large-size gas-air channels are indicated. It is established that the source function method that realizes the statistical energy model of the reflected noise field generated in the channel gives sufficient accuracy in the case of identical sound absorption coefficients on all internal channel fences with the nature of reflection of sound from them close to diffuse reflection. In the event that sound-absorbing linings are unevenly placed on separate surfaces of the channel, a statistical energy method that takes into account the concrete placement of sound absorption in the channel should be used for noise calculations.

Based on the analysis of literary sources and data of various authors assessed the compactibility of asphalt mixtures at low temperature with additives of foreign and Russian production proposed by the author, the coefficient of compactibility. Estimated compactibility of stone mastic asphalt mix XMAS-15 with various additives at a temperature of 80°C to increase the average density of asphalt samples. Determined coefficient of compactibility of asphalt binders when used together, the low-temperature additives and additives based on rubber powder, and also for asphalt binders with different polymer additives. Determined coefficient of compactibility of asphalt binder with liquid containing surface-active substances, low-temperature additives of Russian production. It is established that expressed the technological effect of improving compactibility in the laboratory at low temperatures is observed in the low-temperature flow additives 1-2% by weight of the binder.

It is noted that a particularly large amount of waste of polyvinyl chloride (in the form of scraps), requiring recycling, is formed by mass production and replacement of water pipes. An assessment of the capacity of use in the fine aggregate concrete waste polyvinyl chloride in the form of ground scraps of water pipes. The influence of polyvinyl chloride particle shape on the strength of fine-grained concrete is shown. The conducted researches confirm that introduction in structure of fine-grained concrete of the crushed scraps of polyvinyl chloride pipes leads to increase of its durability on a bend and compression, thus the rational quantity of the entered waste is 1-2 mas. %. It is shown that to increase the bending strength of fine - grained concrete, it is advisable to use the whole rings and half rings obtained by grinding the pipe scraps, and to compress them into quarters of rings. It is revealed that with the increase in the amount of polyvinyl chloride introduced (regardless of the shape of its particles), the density of fine-grained concrete decreases.