The article investigates the hydration processes of free calcium and magnesium oxides, as well as anhydrite, with the formation of ettringite, portlandite, and calcite in the high-calcium fly ash from Berezovskaya GRES. The composition and properties of non-hydrated ash and its hydration products during hardening in water at a temperature of (20 ± 2)°C were determined using physico-chemical analysis methods. Kinetic constants for the reduction of calcium oxide and anhydrite, as well as for the formation of portlandite and ettringite, were determined. It was found that after 7 hours of hydration, 11.5

In response to the growing interest in carbon-neutral fuels, the combustion of biofuels in an air flux, with heating at 20°C/min, is studied by thermogravimetric analysis. The goal is to determine the basic combustion characteristics of the following biofuels: larch sawdust, carbonized larch obtained by gasification at 700–800°C, and larch bark. The biofuels are subjected to technical and elemental analysis. The following characteristics are determined from the curves of mass loss, rate of mass loss, and differential scanning calorimetry: the mass loss, the maximum reaction rate, the maximum intensity of the heat flux, and the exothermal and endothermal effects. On the basis of the intersection of the curves, the ignition and burnup temperatures of the biofuels are established. Carbonization of larch doubles its calorific value. On combustion of the carbonized larch, the maximum reaction rate is lower by 3.5

As part of the work, the chemical interaction of finely ground glass (~1 μm), calcium oxide, and water was studied. It is shown that an increase in the fineness of grinding makes it possible to abandon autoclave hardening in the production of products on a hydrosilicate binder. The study of chemical interaction was carried out by calculating the thermodynamic equilibrium and was also confirmed by XRD analysis. DTA analysis showed that an increase in the treatment temperature leads to an increase in the proportion of the reacted phase at the first stage. Subsequently, phase formation is associated with the presence of CaO. The carrier of strength characteristics is the CaO×2SiO2×2H2O phase. The selection and optimization of the composition make it possible to obtain a high-strength glass concrete material with a strength of about 110 MPa. The micrographs of the obtained samples correspond to classical hydrosilicate systems.

Link for citation: Nazirov R.A., Vede P.Yu., Tarasov I.V., Zhuikov A.V., Sergunicheva E.M., Tolochko O.R. Distribution of natural radionuclides in ashes, collected by thermal power plants electrostatic precipitator. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 7, рр. 177-186. In Rus. Relevance. In the context of the global trend towards sustainable development, there is a problem of utilization of ash and slag waste from thermal power plants. The use of these wastes in the construction industry is of particular importance, due to the resource intensity of the production of building materials. Fly ash in the building materials composition can influence to a large extent the natural radioactivity of structures and increase the background radiation in the buildings. This is due to the fact that when coal combusting, fly ash is enriched with natural radionuclides. Purpose: to study the radioactivity of fly ash deposited on various fields of the electrostatic precipitator. Object: fly ash deposited on the fields of electrostatic precipitators from the combustion of Kansk-Achinsk brown coal in power boilers BKZ-420-140 PT-2. Methods. Content of Ra-226, Th-232 and K-40 was determined by gamma-spectrometric method, the value of the normalized indicator of specific effective activity for fly ash was calculated. The granulometric composition of the studied samples was determined by the method of laser diffraction analysis. Cluster analysis was used for statistical processing of test results. Results. The presence of two clusters in the content of natural radionuclides was established. In the first cluster, which has high radioactivity, the first and second fields of UGZ-4 electrostatic precipitators are combined, and in the second – the third and fourth fields. A correlation dependence was established between the numbers of fields of electrostatic precipitators, the size of ash particles, the content of Ra-226 and specific effective activity was established. No such dependence was found for Th-232. Conclusions. Particle distribution in the fields of electrostatic precipitators is multimodal. The nature of the distribution of each mode approaches the lognormal law. The content of radium and the value of the specific effective activity depend on the size of ash particles and are described by an exponential function. The highest content of Ra-226 is observed in the ashes deposited on the third and fourth fields of electrostatic precipitators, which indicates the enrichment of finer ash particles with this radionuclide. The conclusions obtained correspond to the well-known thesis about the increased radioactivity of ash particles that are not deposited by ash collection systems and enter the atmosphere together with flue gases. The proposed method for studying the distribution of natural radionuclides over the fields of electrostatic precipitators can be used to predict the radioactivity of particles that are not captured by the flue gas cleaning system and released into the environment.

Introduction. All over the world building rating systems (certification systems) are being intensively developed as a solution to problems of modern cities focused on enhancing the quality of life in the population. Certification systems are an effective modern tool used not only to assess buildings, but also to achieve sustainable development goals in the construction industry.­ Materials and methods. The paper reviews several international certification systems, including BREEAM, LEED, DGNB, and Green Globes. The authors describe certification procedures, evaluation categories, areas of standards application and certification in Russia. The article provides a detailed review of the following Russian certification systems and the process of their development: “Green Standard”, SDOS “NOSTROI”, GREEN ZOOM, SDS “RUSO”. Their evaluation categories and basic provisions are provided. Results. The authors have conducted a comparative analysis of the Russian certification systems with account taken of environmental, economic, and social aspects of sustainable development. Russian standards are compared with the international ones and their interconnection is established. Conclusions. In Russia, sustainable development assessment systems have been developed and used since 2010. They focus on environmental and social aspects of sustainability.

This article provides the results of a study to determine the emanation coefficient of artificial construction material, namely heavy concrete produced by semi-dry pressing, depending on equilibrium sorption moisture content achieved in the desorption stage. We measured radon volumetric activity in a sealed chamber at different air relative humidity, determined the specific activity of naturally occurring radionuclides (NORs), and calculated the specific effective activity of NORs. Then we obtained mathematical models of the dependence of the emanation ratio on the degree of pores filling with water, and it was determined that the emanation coefficient increases by almost 50 % in the range of relative humidity typical for residential and public buildings, which necessitates the numerical control of this parameter in order to accurately assess the dose load on the population.

The purpose of the study is to consider the possibility of using microsilica - waste of aluminum production, as filler in a vacuum insulation panel. The properties of silicon dioxide powder have been studied, and compositions and manufacturing technology of vacuum thermal insulation panels on its base have been developed. Differential thermal analysis of powders is carried out; the curves of differential thermal analysis and thermogravimetric analysis, x-ray phase analysis are obtained. The microstructure of the samples is investigated. The thermal conductivity of the manufactured panels is measured. The test results suggest that for the manufacture of low–vacuum insulation panels of microsilica powders, waste production of crystalline silicon can be used. The use of waste in the future can become the basis for the production of high-quality vacuum insulation with low cost.

The composition and technology of obtaining low-vacuum thermal insulation panels with a powder filler of silicon dioxide and infrared silencer have been developed. The thermal conductivity of the low vacuum insulated products with the use of synthetic silica dioxide and micro-silica - waste production with the addition of titanium dioxide at moderate temperatures with samples of 37.5°C and 1.0°C is investigated. The results of electron microscopy of materials studied are presented. The optimal amount of additive-infrared silencer is determined. It has been found out that low-vacuum products based on micro-silica with an optimal amount of additives have a thermal conductivity lower than that of the air at lower temperatures.

ПРИМЕНЕНИЕ МАТЕРИАЛОВ С ИЗМЕНЯЮЩИМСЯ ФАЗОВЫМ СОСТОЯНИЕМ В ОГРАЖДАЮЩИХ КОНСТРУКЦИЯХНАЗИРОВ Р.А

Р.А.НАЗИРОВ 1 , А.В.ТАХТОБИН 1 1 ФГАОУ ВО «Сибирский Федеральный Университет», г.Красноярск, Россия МАТЕРИАЛЫ С ИЗМЕНЯЮЩИМСЯ ФАЗОВЫМ СОСТОЯНИЕМ В ОГРАЖДАЮЩИХ КОНСТРУКЦИЯХ Аннотация.В настоящей статье рассмотрены материалы с изменяющимся фазовым состоянием и способы их размещения в ограждающих конструкциях в качестве теплоаккумулирующих элементов, воспринимающих тепловые нагрузки в процессе эксплуатации зданий и сооружений.С позиции тепловой защиты, наружные ограждающие конструкции обеспечивают комфортные параметры микроклимата зданий и санитарно-гигиенические условия при заданном расходе тепловой энергии, как в холодный, так и в тёплый период времени.Достижение заданных параметров микроклимата зданий, как правило, в традиционном строительстве решается путём увеличения общей толщины стеновых конструкций, что влияет на снижение полезной площади помещений и увеличение нагрузок на несущие элементы здания.Выбор эффективной стеновой конструкции, обладающей сравнительно небольшой массой, высокими теплотехническими характеристиками для проектировщиков, строителей и эксплуатационных служб является актуальной задачей.Рассматриваемые ограждающие конструкции основаны на принципах термодинамики, законах теплового баланса и сохранения тепловой энергии.На основе рассмотренных вариантов ограждающих конструкций с применением материалов с изменяющимся фазовым состоянием, получивших теоретическое обоснование и практическое применение в строительной области, предложены решения по их доработке.Систематизация теплоаккумулирующих материалов по классам и их основным характеристикам позволила определить области их применения для конкретных приложений в строительстве, задать концепт по дальнейшей разработке энергоэффективных и безопасных зданий в зависимости от назначения и типа ограждающих

The article presents special research aimed at the estimation of radon permeability change in cement-sand solution after applying a padding layer of the gypsum on its surface during the process of forming the additional layer of gypsum paste to decrease radon permeability of cement concretes and solutions.

The simple mechanical transfer of structural technologies to high-latitude construction engineering is not efficient. But construction engineering nordifikation seems to be effective and expedient, for example working camps. Severe, extreme conditions in the Arctic are similar to extraterrestrial, for example, Martian therefore use of space technologies is required here. From this point of view, it is expedient to build space frame constructions such as: domes, lenses, spheres, Rello’s cones united by the covered transitions of ribbed type or the common covering, having good aerodynamics. In this article is emphasized the rationality of designs made of timber itself and wood materials that defines need of creation of the glued elements industry, that is possible only in presence of government support

The topicality of studied subject is based on inappropriate usage of different materials in wooden structures, since using metal joint in wooden construction leads to reduction of construction working life cycle. In this regard, a study of several options for wooden screw carving was conducted in order to determine the most appropriate one (screw). There are several different types of carving, such as: trapezoidal, triangular, rectangular, etc. The most appropriate ones are trapezoidal and triangular-section threads for wooden screws. The effectiveness of a wooden screw thread was determined from the conditions (capacity) of shear fracture and bearing stress. After analyzing the results of calculations of the specific capacity for shear fracture and bearing stress, it can be concluded that the value of specific bearing capacity for shear fracture is less than the value of bearing stress by 1.3%. Therefore, a further comparison of the trapezoidal thread and the triangular cross-section will proceed from the spalling conditions. It has been found that the most effective thread is a triangular cross-section. Based on the results of calculations, a mathematical model has been established that describes the dependence of the carrying capacity on the screw diameter.

The implementation of spatial foundation platforms on permafrost soils is justified in this paper. The stress-strain state of the spatial foundation platform under the building of a lens-shaped structure at different heights of the ventilated space is investigated. The structural solution of the spatial foundation platform is made in the form of a plate-and-rod structure. The calculation is carried out using the SCAD software package. The parameters of the rods and nodal joints of the spatial foundation platform are determined. With the help of the COMSOL Multiphysics software package, temperatures are investigated throughout the year in the central part of the platform under its lower belt.

While making calculations for non-steady heat-and-moisture exchange processes in building envelope constructions it is necessary to consider moisture sorption isotherms of the materials in use. Fifteen aqueous vapor sorption models have been analyzed in order to select the simplest one that represents conventional equilibrium wood moisture values in the most accurate way. Hailwood-Horrobin and Peleg modified equations with three and four empirical constants respectively are the most suitable ones for description. When selecting models for calculations in a climatically defined range of air temperature and relative humidity values, these equations might be in preference to others. The dependence of the constants in these equations on the ambient air temperature have been calculated.

The influence of air pollution on the area where Siberian fir tree (Abies sibirica)grows on the synthesis and accumulation of both essential oil and its separate components is researched. The data that the increase in the content of pollutants in the air reduces the amount of sesquiterpenes and oxygen-containing terpenoids in the arboreal greenery of the Siberian fir-tree (Abies sibirica)is received.