Vol. 6 Issue 3

Archives Journal Construction Materials and Products 2023

Method for calculating the strength of massive structural elements in the general case of their stress-strain state (kinematic method)

https://doi.org/10.58224/2618-7183-2023-6-3-5-17
Abstract
A variant of the kinematic method of the theory of limit equilibrium is proposed; massive structural elements are considered, the material of which, in the general case, is anisotropic.
A rigid-plastic model of a deformable solid body is adopted. It is assumed that massive structural ele-ments are destroyed by dividing into parts that deform relatively little (“absolutely rigid finite ele-ments”, ARFE) and have 6 degrees of freedom in three-dimensional space. The process of destruction of the material goes along infinitely thin generalized destruction surfaces (GDS), on which the work of all acting internal force factors (IFF) is taken into account – 9 forces and 9 moments. Bodies made of homogeneous isotropic materials that resist tension and compression in different ways are considered. The strength surfaces in the IFF space are described by the corresponding parametric equations.
Using the equilibrium equation in the Lagrange form and the Mises maximum principle, as well as the proposed parametric equations of the limiting surface, the problem of determining the minimum value of the possible kinematic parameter of the load is reduced to a standard linear programming problem (LP), which is solved using the simplex method.
PDF

Big Data in Predicting the Climatic Resistance of Building Materials. I. Air Temperature and Humidity

https://doi.org/10.58224/2618-7183-2023-6-3-18-30
Abstract
The article provides a comparative analysis of the quantitative values of temperature and relative humidity of the ambient air calculated according to GOST 16350-80 for a moderate continental climate (representative location – Moscow), and obtained at the meteorological station of Ogarev State University (Saransk) for the period from 2015 to 2022. A significant discrepancy between the calculated and accumulated values of meteorological factors has been established. In the studied time interval, the spread of the difference between the calculated and accumulated values ranged from -5.8 to 10 oC for air temperature and from -36.4 to 32.5% for relative humidity. There is also a significant variation in the difference of the studied indicators depending on the calendar month, as well as a de-viation of a number of distribution curves from the normal form, which, in general, indicates the im-possibility to reliably assess distributions using only the value of the quadratic deviation recommended by GOST 16350-80. It has been established that the use of calculated distributions virtually does not allow taking into account events occurring near the boundaries of the distributions of the studied me-teorological parameters. This, in turn, irreversibly affects the accuracy of forecasting the climatic aging of building materials. When predicting the climatic resistance of materials by machine learning methods, it is proposed to use absolute humidity values instead of relative humidity as a sign that has a clear physical meaning (mass of water vapor contained in 1 m3 of air), as well as defined only in the range of non-negative values.
PDF

Three Bimoments Equation of V.I. Slivker’s Semi-Shear Theory for the Calculation of Multi-Span Thin-Walled Beams

https://doi.org/10.58224/2618-7183-2023-6-3-31-46
Abstract
This article discusses the method of static calculation of multi-span thin-walled beams with bending torsion in the framework of the semi-shear theory of V.I.Slivker. The main advantage of the semi-shear theory is that it is suitable for rods of both open and closed (as well as open-closed and multi-contour) profiles due to the similarity of differential equations according to the theories of V.I. Slivker and A.A. Umansky, and also increases the accuracy of the calculation due to taking into account part of the shear deformation. The analytical solution of the problem is obtained based on three bimoments equations system of, including values of correlating functions for cases of application of torsional loads in the span and on the cantilever of thin-walled multi-span continuous beams. Bimoment func-tions for a number of simple beams are obtained within the framework of the semi-shear theory. It is shown that the values of the parameter of the influence of the shape of the cross-section of the semi-shear theory ranges from 1.000086 to 1.0014 for channel profiles, while the presence of shelf bends (C-profile) in comparison with the channel profile reduces the value of this parameter by 10%, which indicates a lower contribution of part of the shear deformations to the stress strain state at the torsion of the C-profile. It is shown that, despite the convergence of the calculation results by the proposed method, due to the proximity of the values of the shape influence parameter to 1.0 with the similar one according to the theory of V.Z. Vlasov, the area of application of the proposed method are significant-ly wider (both open and closed profiles).
PDF

ESG-security of Urban Economy in the Concept of Sustainable Development

https://doi.org/10.58224/2618-7183-2023-6-3-47-58
Abstract
The article considers the importance of ESG-security of the urban economy, reveals the relevance of this area of research, analyzes foreign and domestic environmental standards. Also, an analysis was made of the use of certification in the Russian market, the territories where "green" objects predominate were considered, and it was also considered what results "green" construction brought to these objects. Within the framework of scientific work, an analysis of the attitude of the state to envi-ronmental safety was carried out using the developed standards and national projects as an example, and improvement measures were proposed.
The development of cities is accompanied by constant construction. This development cannot be stopped; accordingly, it is impossible to stop the expansion of territories through construction, which in one way or another implies an impact on the environment. But this impact can be minimized and balanced with the help of "green" building. It will help reduce the risk of environmental pollution and the negative impact on the person himself. Understanding the need to create ESG security will help prevent an environmental crisis.
Awareness of the state of ecology today is present both among the population and the state, which is a positive trend on the way to improving the environment and people's lives. Despite the fact that this understanding has appeared relatively recently, it is actively gaining popularity abroad and in Russia, however, it must be instilled, including in the population at the regional and local levels, and not only in large cities. It must be learned that the use of environmentally friendly consumables in construction will help create a better future for us and future generations, without requiring large investments.
PDF

Ecological Safety of Construction in Single-Industry Town

https://doi.org/10.58224/2618-7183-2023-6-3-59-78
Abstract
Ensuring environmental safety during construction works is an important condition for the sustainable development of single-industry towns. The high rate of urbanization, population growth of single-industry towns and their active construction leads to negative anthropogenic changes in the en-vironment, which negatively affects both the ecology and the life of the population of a single-industry town. In this article the basic factors of the influence of the sphere of construction on the environment are considered, the aspects of providing ecological safety during construction are investigated, the normative-legal base regulating these aspects during construction works is analyzed, and also possible approaches and measures to decrease the negative influence of construction on the environment in monotowns are given.
The article proposes measures to reduce the negative impact on the environment and improve envi-ronmental safety of construction in single-industry towns, such as complementing the existing legisla-tion with stricter standards and requirements to ensure environmental safety during construction work in single-industry towns, development and active implementation of modern environmental materials and technologies, strengthening environmental control mechanisms of the construction sphere in sin-gle-industry towns and raising awareness of business and population. The article was prepared based on the results of research carried out at the expense of budgetary funds under the state assignment of the Financial University.
PDF

The Planning of Intra-Block and Open Urban Spaces in the Historic Environment of the City: a Socio-Managerial Aspect

https://doi.org/10.58224/2618-7183-2023-6-3-79-97
Abstract
Urban space is a system of open architectural spaces with elements placed in them. However, the purpose of their organization is not limited to the creation of a network of building-free spaces, it is also to meet the needs of society. This applies without exception to all types of urban space of different public purposes.
The aim of the article is to illuminate the socio-managerial aspects of the planning of intra-block and open urban spaces in the historic environment of the city.
The paper defines the terminology and analysis of the formation and development of existing intra and open urban spaces of the historic part of the city with the definition of their functions. The analysis of the main problems of intra and open urban spaces in the historic development of the city and the ways of their solutions proposed.
The article concludes that the priority task of planning of inner and open urban spaces in the historic environment of the city is not only the design of the various elements, but also the study of the city in its potential development, the rethinking of its nature to create new properties and characteristics of urban space, where the dominant matter is the individuality of environment, namely the historically established area.
The results of the study can be used in the practice of reconstruction of urban spaces in the historic part of the city.
PDF

Regional plans for solid waste management: Distinctive features of practice in Russia and EU countries

https://doi.org/10.58224/2618-7183-2023-6-3-98-118
Abstract
Effective management of municipal solid waste (MSW) is a comprehensive problem that appears among the highest priorities on the global environmental agenda. In 2015 and 2022, a landfill filtrate was studied at a landfill for the disposal of solid household waste in the Leningrad region (Russia) to determine the content of various chemical and toxic substances. By comparative analysis of the monitoring results, it was revealed that landfill soil is extremely dangerous. The excess of the maxi-mum permissible concentrations of heavy metals in the filtrate ranged from 2.5 to 67.5 times. This paper presents the results of the analysis of landfill filtrate taken in 2022 from sanitary protection zones and compared with previous data. It was found that the danger associated with the landfill of municipal solid waste is that chemical and biochemical processes occurring between the various com-ponents of landfill filtrates lead to the formation of toxic compounds and are a source of infectious infections. Regional differences and a shortage of effective international instruments often hinder the solution of this problem, making it difficult to develop and apply innovative mechanisms. These con-ditions act as determining factors in the development of state programs for socio-economic develop-ment, particularly in Russia. Political and legal initiatives that have been adopted, in particular those that are part of nation-scale projects, have not yet received impulses for full-fledged practical imple-mentation.
PDF