No 6 (2024)

The operation of buildings with translucent facades increases the load on the heating and ventilation system due to transmission heat losses through the glazing, and on the air conditioning system due to possible overheating in summer. For this reason, glazing with sun protection, low-emissivity and multifunctional coatings is used in such facades. The characteristics of translucent enclosing structurers, as calculated according to normative documents, are taken into account when calculating the load on heating, ventilation and air conditioning systems, as well as when selecting the structures themselves in a given climate in order to save energy. In this case, the characteristics of the glazing were obtained in laboratory conditions when the radiation is perpendicular to the glazing, which is different from field conditions where the sun rays fall on the glazing at an angle. The available research works on the transmittance of solar radiation falling on glazing at an angle is based on laboratory studies, where various physical processes cannot be manifested and accounted for. Currently, research is being conducted in the Research Institute of Building Physics of the Russian Academy of Architecture and Construction Sciences to determine the empirical dependence of the light transmission coefficients of glazing with special coatings on the angle of incidence of the sun rays. The article presents part of the research and considers the determination of the light transmission coefficient of glazing with and without coatings from the angle of incidence of solar radiation.

In modern construction practice, partition structures are often used that do not meet regulatory requirements for airborne noise insulation. This reduces the acoustic comfort and safety of people in the rooms. An urgent task of building acoustics is to find structural solutions for enclosures with the required sound insulation properties and minimum values of surface density and thickness. New design solutions were considered: a lightweight frameless partition with acoustic isolation of the shotcreted claddings and the middle layer; lightweight frameless partition with acoustic separation of layers and fragmented shotcreted claddings. As analogues currently used in the design and construction of civil buildings, lightweight single-layer partitions made of tongue-and-groove gypsum slabs, gas silicate blocks, monolithic gypsum concrete, as well as multilayer lightweight frame-sheathing partitions are considered. A methodology has been developed for assessing the rationality of new design solutions for sound-insulating lightweight partitions in comparison with analogues. At the first stage of the assessment, enclosures that do not meet regulatory requirements for the value of the airborne noise insulation index are excluded. After this, a comparative analysis of the design solutions of the partitions is carried out according to two parameters: surface density and thickness. The results of the completed assessment are presented in tabular and graphical forms. An evaluation of a lightweight partition with shotcreted claddings in comparison with a frame-sheathing partition showed the rationality of the new type of enclosure in terms of surface density. The developed methodology for assessing rationality is recommended for use in the design of civil buildings. This will eliminate the use of lightweight partitions that do not meet regulatory requirements and select rational design solutions without inflated values of surface density and thickness.

Currently, one of the main problems of the world community has become the problem of climate change on Earth, global warming has been recorded. On the territory of the Russian Federation, the average surface air temperature rises at a rate of 0.43^оC per decade, which is more than two and a half times the rate of global warming and is recorded mainly in the winter and spring seasons. Important applied parameters of the cold season are the climatic characteristics of the heating period. Its duration and average temperature are the main indicators in estimates of energy costs for heating buildings. Reducing the average duration and increasing the temperature of the heating period create conditions for reducing the consumption of thermal energy. The reduction of energy costs during the heating period refers to the possible positive consequences for the Russian Federation of the expected climate changes, which have a significant potential for effective sectoral and regional economic development. For the rational use of climate change, it is necessary to take them into account in building codes. In the presented work, based on 60 years of observations by the Meteorological Observatory of the Faculty of Geography of Moscow State University, the variability of the main characteristics of the heating period in Moscow is analyzed. It is shown that there is a tendency to decrease the degree-day of the heating period, although there are years when the main characteristics of the heating period advise the climatic norm of earlier observations.

Highly porous materials are the basis for four product groups: heat insulation, sound insulation and sound absorption, as well as insulation filling. In all cases, the parameter determining the properties of these materials is porosity, which also determines the conditions for energy transfer in the material. Pore size and shape, pore size distribution and porosity, thickness, structure, and nature of inter-ring membranes are also important characteristics (determining, first and foremost, their strength. These features of the structure and their influence on the properties of materials can be considered in the implementation of structural and mathematical models. The article describes the method and results of construction of complex structural model of high porous products on the example of particularly light and heat insulating mesh concrete. Analytical expressions for compressive strength, medium density and thermal conductivity are obtained. A nomogram has been constructed, with the help of which prognostic tasks of assessment of properties of mineral products of honeycomb structure can be solved depending on their porosity and nature of the structure-forming component.

In recent decades, high-rise construction has been actively developing in the Russian Federation. This led to a significant increase in aerodynamic studies of high-altitude objects in accordance with the methodology of SP 20.13330.2016 «SNiP 2.01.07-85* Loads and Impacts». In many domestic and foreign works, when conducting such studies, the step in the azimuth angle of the wind flow is 15 degrees (less often 20 degrees). This paper presents results that show that such a wind azimuth step, in conditions of dense multi-height buildings, results in a significant underestimation of local negative peak wind loads. The question of sufficiency of the wind flow azimuth step of 5 degrees is discussed.