The requirements to a desired level of thermal protection of outer walls of buildings have been analysed. The relation between such requirements and social factors of a country was shown. Comparison data regarding heat releasing surface area of outer walls and windows and heat losses per person have been received for variable residential density of apartments. The authors have shown international practices and the needs for transition to construction of buildings with a higher level of thermal protection of outer walls. Since cold generation is 3-5 times as expensive as heat generation for many buildings, the transition was made from ventilation of the naturally driven type to controlled and mechanical one providing heat recovery of exhaust air. It was suggested that problem of energy-saving in the sector of construction and housing and communal services could be solved providing a desired life of outer walls and costs of current and major repairs required for projected lifetime of a building.

Autonomous power systems serving remote areas with weather stations with small settlements are characterized by a fairly high cost of generating electricity and the purchase and delivery of fuel. In addition, diesel power plants require regular maintenance, have a relatively short service life during continuous operation and produce a large amount of emissions into the environment. This article discusses various methods of placing solar panels in the space for the autonomous power supply of weather station equipment. The principles of these methods are described and their advantages and disadvantages are outlined. The optimal algorithms of functioning for photomodules are described and their comparison regarding the main, significant parameters is carried out. The choice of the most effective algorithm for use at a weather station is made. The effective positioning of solar panels is also calculated, and positioning conditions are determined depending on the territorial location and various environmental conditions. Simulation of the power supply system of a weather station consisting of solar panels, batteries and inverters is performed. As a result, a practical example of the application of the method of selecting the optimal composition of equipment for a hybrid power system of a weather station territorially located in Siberia with different configurations of equipment is considered. In numerical terms, it was possible to reduce the cost of power equipment operation by more than 60% with a fairly low payback period of 5.5 years and an increased reliability of the power system, which is very important for autonomous power systems of northern weather stations.

No abstract

This article reports on a new composite gypsum binder (CGB) with nanostructured silica-based admixture (NSS). NSS is obtained by a wet ultrafine milling of quartz sand resulting in the formation of an inorganic polydisperse binding system, which has a high concentration of active nanoscale phase (about 10%). Developed CGB contains hemihydrate gypsum and nano-component based on quartz sand. It is observed that the addition of 15–20 % of NSS improves the rheological properties of gypsum systems through the formation of solvate shells hindering the access of water to gypsum particles; this process also retards the setting of binder.The experimental program used infrared IR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) to reveal the contribution of NSS. The porosity of CGB is analyzed by the kinetics of water adsorption and BET. The XRD and IR investigations determined the formation of a new sulfosilicate phase, hydroxyellestadite during the hydration of CGB. With the addition of NSS an overall reduction in pore volume, as well as the shifts in macro-, meso- and nano- porosity values are observed.Analysis of CGB microstructure reveals that in the presence of the NSS the size and morphology of crystals are changed contributing to the formation of dense fine-grained structure. Experimental studies have demonstrated that the composite gypsum binders with NSS are characterized by reduced water absorption and increased density, as well as improved mechanical performance especially, higher compressive strength.

Critical risks of ecosystem identity violation in the structure of landscape-recreational formation of the environment of cities and small settlements are identified. The dependence of the functional load of urban areas with industrial and civil facilities and the ability to restore the ecosystems of the adjacent small rivers and reservoirs is established. The necessity of modeling urban areas based on the “attraction zone” and “exclusion zone”, the verification of technical solutions for engineering systems of water protection complex harmonized with the natural environment is substantiated. A conceptual model for controlling of the risks of developing urban areas is proposed, that is focused on the mechanism for managing water body renovation programs taking into account risk factor analysis. A technique has been developed for restoring water bodies to the level of harmonized functioning by means of anticipatory diagnosis of risk-failures of the danger of environmental disruption. The introduction of digital indicator that determines the level of harmonized stability of functioning of engineering systems of water protection complex in the environment as an additional indicator of the economic and environmental activities of the regions will improve the accuracy of assessing environmental benefits and losses in planned projects.

The work presents the results of development of the composite gypsum binder (GB) with nanostructured binder on the basis of silica component (NBC). Introduction of NBC changes the kinetics of hardening, as well as improves physical and mechanical properties of gypsum system. Analysis of the microstructure of the GB has demonstrated in the presence of the NB the size and morphology of crystals are changed, promoting the formation of fine-crystalline structure and increase the contact area between new formations, compared to NBC – free gypsum system. Experimental studies have shown that the mechanical properties of the composite gypsum application of NBC increased, reduced water absorption, density increases, and increases the setting time.

No abstract

In this paper, we investigate the surface temperature of a wall with a facade heat-insulating composite system (FHIC), which has a thin plaster layer, taking into account solar radiation exposure at different degrees of cloudiness during the month. The object of study is a wall with FHIC, on the outer surface of which temperature sensors were mounted and measurements were taken. Air temperatures were also measured for one month of the warm period of the year. The coefficient of absorption of solar radiation by the surface of the facade is calculated based on the measurement of the spectral reflection coefficient. Measurements of direct and scattered solar radiation arriving on a horizontal surface were carried out, and the cloudiness of the sky was also recorded. The calculation of direct and scattered solar radiation was carried out, taking into account the shading of surrounding buildings using the authors’ novel methods. The experimental days were divided into three groups according to the degree of cloudiness; statistically significant differences between the groups for the studied parameters were demonstrated. The temperature of the outer surface of the wall was calculated according to A.M. Shklover’s formula. The measured values of the temperature of the outer surface of the wall were compared with the calculated ones. It was shown that there is a good correlation between the measured and calculated temperatures for different degrees of cloudiness. At the same time, for days with no or slight cloudiness (Group I), when direct solar radiation predominates, the differences reach 1.7 °C; smaller differences are observed for days with average cloudiness (Group II) during daytime hours, with a maximum difference of 0.5 °C; and on days with continuous cloudiness (Group III), when only scattered radiation is present for daytime hours, the maximum difference is 0.3 °C. Statistically significant differences were found between the measured and calculated temperatures for groups of days, divided by the degree of cloudiness, for the experimental period of a day from 10 a.m. to 5 p.m., which indicates the possibility of considering amendments to A.M. Shklover’s formula for sunny days. The results of comparing the measured and calculated heating temperatures of the facade surface also indirectly confirm the correctness of the author’s calculations of the incoming solar radiation, taking into account the effect of the surrounding buildings. The results obtained can be used to study the inertia and durability of building structures under solar radiation.