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Том 7 №3

Архив журнала Строительные материалы и изделия Том 7 №3

Analysis of thermal efficiency of external fencing made of innovative ceramic blocks

https://doi.org/10.58224/2618-7183-2024-7-3-1
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Аннотация
The paper presents a comprehensive theoretical study of the external fencing structure made of innovative Porortherm 38 ceramic blocks in comparison with traditional structures made of solid ceramic brick, hollow ceramic brick and gas block. The study was conducted in the climatic conditions of Shymkent city, South Kazakhstan. The middle temperature values of the frostiest 5 days with a provision of 0,92 were adopted as the external temperature. The results of the study of the actual resistance (Rf) of the structures under study showed that all adopted structures meet the condition Rf˃Rreq, while the actual resistance of the new structure is 1.3 times more efficient than traditional ones. The analysis of temperature fields showed that the new structure is 2% more efficient than traditional ones. Moreover, no additional insulation costs are required. The obtained results were also confirmed by computer modeling in the ELCUT software package. The results of calculating the humidity regime showed that a condensation area appears in almost all the structures under consideration. The results of calculating the amount of moisture evaporated from the multicoat structure of the external fencing during the torrefaction period showed that all the accumulated moisture will evaporate during the specified period, the calculation of the condition of inadmissibility of moisture accumulation in the structures of external fencings for an annual period and for the period of moisture accumulation showed that all the considered structures meet the requirement . The results of calculating the air regime of multicoat structures of external fencings also showed that all structures including the new one meet the condition . The result of calculating the value of thermal inertia (D) in the proposed structure is up to three times more efficient than traditional structures, which applies to structures with high inertia (7˂D). The obtained results of the study indicate that the new proposal of a structure made of ceramics is cost-effective, innovative blocks can be proposed as a supplement to the register of materials of existing standards.
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Influence of corn cob ash additive on the structure and properties of cement concrete

https://doi.org/10.58224/2618-7183-2024-7-3-2
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Аннотация
In accordance with the Sustainable Development Goals (SDGs) concept, there is a need to find technologies that would help make concrete production less energy intensive and more environmentally friendly. One technology involves substituting some mineral components in concrete with rapidly renewable plant-based alternatives. This study aims to establish the essential patterns among the concrete composition, micro-structure, and properties of cementitious composites modified with corn waste. Additionally, it seeks to explore the potential for producing high-quality composites using this waste material. To assess the effectiveness of this kind of waste, the strength of the cement-sand mortar, several characteristics like compressive strength, flexural durability and water absorption of hardened concrete were studied. It is established that introducing corn cob ash (CCA) to substitute a part of the cement up to 16% is justified and allows to obtain mortar and concrete with enhanced properties. CCA has a beneficial impact on the properties of Cement Sand Mortar (CSM) when replacing cement by no more than 15%. The maximum effect was achieved at 10% CCA, and the rise of compressive and flexural strength were 6.06% and 6.32%. In concrete with a CCA amount of 8%, the most impressive growth of compressive strength was 7.14%, and the lowest value of water absorption, which is 10.31% lower compared to the ordinary composition. Including CCA reduces the properties like workability, density of concrete mixtures, and the hardened composite density. The scientific results obtained prove the possibility of using CCA as an effective mineral pozzolanic additive that improves the properties of concrete.
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Hydraulic activity of crushing screenings of waste open-hearth slag

https://doi.org/10.58224//2618-7183-2024-7-3-3
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Аннотация
Theoretically and experimentally studied the hydraulic activity of crushing screenings of waste open-hearth slag and methods for intensifying the hydration hardening of slag stone during operation. During the hardening of slag stone, three periods of pronounced syneresis with gel new formations strengthening the material were established at the ages of 28 – 60, 90 – 180 days and 1 – 2 years. The first period of syneresis, in contrast to the subsequent ones without changing the strength of the samples, is recorded by the linear shrinkage of the samples, the squeezing out of bound water and the increase in pH. The introduction of two percent of cement dust or lime into the crushing screenings of waste open-hearth slag leads to the strengthening of the slag stone at 28 and 90 days of age by 3 – 4 times. However, by the age of two years, the strength of the samples stabilizes. This fact indicates that the additions of cement dust or lime are not additional binders, but hardening accelerators.
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Analysis of the effect of porosity on thermal conductivity with consideration of the internal structure of arbolite

https://doi.org/10.58224/2618-7183-2024-7-3-4
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Аннотация
A theoretical study of the effect of porosity and internal structure of the exterior envelope in the ANSYS and BLENDER software systems has been carried out in the paper. As an example of exterior enclosure structure, an arbolite block with porosity up to 20% and fiber structure in the direction along and across the heat flux, as well as randomly and at an angle of 45° was studied. As a result of the study, it was found that the significant effect of the heat flux dependence on the porosity of the material is the porosity of the block over 10%, which reached up to 5.92%, and with porosity up to 5% showed a difference of 1.3%. At the same time, the fiber structure also showed a significant difference from 8.16% to 15.33% depending on the fiber direction. At the same time, the analysis of the effect of porosity on the thermal conductive value also showed a difference of up to 15.33% for the same value of heat flux. At the same time, the influence of fiber structure shows an additional difference of up to 5.9%. The results of the study showed that the most thermally conductive arbolite blocks are, those in which the direction of fibers are located along (along the X axis) and at 45 ° relative to the structure of fibers across (along the Y axis) and random, the difference of which was up to 1.6%. The obtained results of this study, further excluding the costly experiments to determine the coefficient of thermal conductivity can be used to accurately estimate the coefficient of thermal conductivity of external envelopes made of arbolite blocks, considering porosity and fiber structure in the design of residential buildings.
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Methodology for determining true temperature stresses during the construction of massive monolithic reinforced concrete structures

https://doi.org/10.58224/2618-7183-2024-7-3-5
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Аннотация
The purpose of the article is to develop and test a simplified method for calculating temperature stresses during the construction of massive monolithic reinforced concrete structures. The essence of the method is to calculate the stress-strain state in standard FEM complexes (ANSYS, Abaqus , etc.) with constant physical and mechanical characteristics of concrete over time, followed by recalculation to true stresses, taking into account the dependence of the elastic modulus of concrete over time. The methodology is based on the hypothesis of equality of temperature deformations for structures with a constant and time-varying modulus of elasticity of concrete. The developed
methodology was tested on experimental data for a massive monolithic foundation slab. The calculation at a constant modulus of elasticity of concrete was carried out in the ANSYS software package. Conversion to true stresses was implemented by the authors in the MATLAB environment. A good agreement between the calculated stress values and the experimental values was obtained.
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The effect of temperature difference on bending of external panel walls

https://doi.org/10.58224/2618-7183-2024-7-3-6
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Аннотация
One of the most common structural systems of buildings intended for various purposes is a prefabricated panel system of factory-made elements assembled on-site. Single-layer structures made of lightweight concrete are widely used as envelopes of these buildings. In buildings operated under various climatic conditions, exterior wall panels, as well as other envelopes, are exposed to thermal deformations and, accordingly, changes in the stress-strain state. As the temperature changes, corresponding stresses and deformations occur across the thickness of the exterior panels. To analyze their values, the bending moments and support reactions of single-layer lightweight concrete panels of different length and thickness in the range of temperature differences from 0 °С to 65 °С have been calculated. It was found that the bending moments and support reactions of 1,500 mm long panels decrease as the thickness of the panels increases over the entire temperature gradient. The values of bending moments and support reactions of panels with length of 3,000, 4,500 and 6,000 mm decrease only when the temperature rises from 0 to 10 °С, in the rest of the range 15–65 °С – increase as the thickness of the panel increases due to the bending stiffness.
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Properties of Verkhnealkunsky deposit mudstones used as raw materials to manufacture clinker tiles

https://doi.org/10.58224/2618-7183-2024-7-3-7
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Аннотация
The article writes about the development of mudstone-based raw material compositions used to manufacture clinker tiles with improved physical and technical properties. Clinker tiles are one of the popular roofing materials. Compared to other roofing covering options, clinker tiles have higher strength, more resistance to aggressive environments, and better aesthetic characteristics. Clinker tile production is relevant due to the fact that currently architects and building constructors are showing great interest in such an elite roofing material, but due to the economic situation, this roofing material is no longer imported to Russia, with an empty market niche having been formed. Many Russian brick factories are planning to install additional technological lines to manufacture ceramic tiles, but the current demand is to produce clinker tiles. The main unresolved issue concerns raw materials since traditional raw materials – loams and clays – are very rarely suitable for the production of low-temperature sintering clinker tiles. Having studied a large amount of academic literature and carried out the necessary laboratory studies, the authors of this article, under the guidance of the Chair of the Construction Materials Department, Prof. V.D. Kotlyar, pay serious attention to such raw materials as mudstones from the Verkhnealkunsky deposit of the Russian Republic of Ingushetia. The article provides a general description of mudstones, including their chemical and mineral composition as well as their structural features for the production of clinker tiles. It has been experimentally established that the degree of their grinding has a significant influence on technological properties of both mudstones and the end products. Based on raw material mixtures with a grain composition of 0-0.16 and 0-0.08 mm, it is possible to manufacture clinker tiles using the extrusion molding method without introducing corrective additives. The data obtained will make it possible to develop technological regulations to manufacture clinker tiles based on Verkhnealkunsky deposit mudstones.
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Traditional archetypes of institutions for the socialization of orphans in the Arab world

https://doi.org/10.58224/2618-7183-2024-7-3-8
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Аннотация
The article identifies the traditional archetypes of social care institutions for orphans. Modern architectural solutions do not take into account the centuries-old traditions that have developed in Arabic architecture. Based on the method of historical and genetic analysis of objects of traditional architecture of children's educational institutions in the Islamic world, the article identifies stable elements of the system that allow maintaining the stability of development and determining genetically important features of architectural and planning solutions.
For the formation of steadily developing architectural and planning solutions, the interrelations of the functional zones of educational complexes that do not contradict the traditions of Islam are determined. Rethinking these traditions in the light of new construction technologies will create an innovative product that can develop sustainably in today's dynamic world. In the context of the crisis of the 21st century, which is taking place in Syria and the Middle East today, a new interpretation of identity and cultural continuity will solve the problem of the demand for children's educational institutions for orphans in Syria during the period of reconstruction of the country. In the modern world, social protection of children is one of the priority areas for the development of a civilized society and state. The conditions in which a child's personality is formed have a great impact on the socialization and future of a citizen of the country.
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Green building in the ESG agenda for sustainable development of Russia: conditions and trends

https://doi.org/10.58224/2618-7183-2024-7-3-9
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Аннотация
To achieve the sustainable development goals proclaimed by the UN, we need to use more green building technologies that meet the principles of sustainable development, increase energy efficiency and achieve the environmental direction of the country’s ESG transformation. The authors consider the main problems and directions of green building in the Russian Federation. The study highlights the main limiting factors to develop green building in the domestic building industry. It was revealed that the main ones are related to the inconsistency of legal regulation, lack of demand from consumers, lack of specialists in the field of green building, assessment and certification of green objects. The study found that no more than a third of the country’s population knows about green building, only 20% are aware of the need for environmental certification of buildings, and only 6% of the population require this certification when purchasing housing. At the same time, the development of green building is hampered by difficulties with import substitution of green technologies and green building materials. The purpose of the study is to analyze the conditions and trends for green building development in the Russian Federation. The scientific research hypothesis is to introduce the ESG principles into building as an effective approach for sustainable development in Russia. The main conclusion of the study is to develop incentive tools for transition to green building technologies and green certification of building projects. The results of the study will contribute to the expansion of green building projects in the domestic building industry.
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