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Vol. 7 Issue 4

Archives Journal Construction Materials and Products Vol. 7 Issue 4

Improving the procedure for interaction between participants in the construction control system in order to increase labor productivity

https://doi.org/10.58224/2618-7183-2024-7-4-1
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Abstract
In connection with the current demand for reducing the implementation of investment and construction projects, there is a need to determine the risks that affect the duration.
Within the framework of building and construction works, there is a risk of various destabilizing factors arising, leading to economic losses and increased construction period, and consequently a decrease in labor productivity.
Existing administrative barriers, maintaining and coordinating a large amount of executive documentation leads to high costs of various resources. In this regard, the work optimized the functioning of the construction control system.
The study identified factors that influence the functioning of the construction control system. A rational procedure for carrying out construction control of capital construction projects has been determined.
The study used such methods as: the method of expert assessments, statistical data analysis, and the Varimax rotation method.
The results of the study were introduced into the activities of the organization performing the functions of a developer at the stage of construction of objects.
As a result, a method of interaction between participants in the construction control system has been formed, which allows increasing labor productivity.
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Study of thermophysical characteristics of variatropic concretes

https://doi.org/10.58224/2618-7183-2024-7-4-2
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Abstract
An important task in the development of the construction industry is to find rational technologies, materials and solutions that ensure energy efficiency in construction and create conditions for obtaining energy-saving products and structures for various construction projects. At the same time, the issue of structures made of the same material, but having a difference in their properties and characteristics in thickness, the so-called variatropic building material, which, due to differences in structure and properties, ensures variatropic properties of the building structure itself, has been poorly studied. The goal of this study was to eliminate a significant scientific deficit, consisting in the absence of a systematized knowledge base on the structure and thermophysical properties of variatropic products and structures made of concrete or reinforced concrete. The modeling was performed in the ANSYS environment (Ansys version 2024 R1). An element selected for modeling was a ring-section heavy concrete pillar with an outer diameter of 450 mm and an inner diameter of 150 mm. Variatropy was specified by conventionally dividing the element’s cross-section into several layers with different physical and mechanical properties: three for centrifuged concrete and four for vibrocentrifuged concrete. In the course of modeling, the authors determined the main initial data for the calculations, and based on the results of the calculations, dependencies were established confirming the improvement of the concrete’s heat-insulating properties due to the use of centrifugal compaction technology. The phenomenon of variatropy leads to an increase in heat-transfer resistance – from 13% for centrifuged concrete to 23% for vibrocentrifuged concrete in comparison with vibrated concrete. At the same time, vibrocentrifuged concrete turned out to be 8% more efficient than centrifuged concrete in terms of “heat-transfer resistance”. The conducted modeling shows that variatropic concrete is promising for further research and practical application in terms of its thermophysical characteristics.
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Specific heat dissipation of concrete and the risk of early cracking of massive reinforced concrete foundation slabs

https://doi.org/10.58224/2618-7183-2024-7-4-3
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Abstract
Introduction. The modeling of temperature fields and stresses used to prevent the risk of early cracking of massive monolithic reinforced concrete structures determines the relevance of improving the algorithm for calculating temperature stresses due to the «center-top» temperature difference depending on the magnitude and kinetics of heat dissipation of concrete, autogenous shrinkage, heat transfer conditions and ambient temperature. Purpose of the study: modeling of temperature fields and stresses of massive structures using the example of a flat foundation slab 1.5 m thick based on the proposed dependencies of the kinetics of strength, heat dissipation, autogenous shrinkage, and deformation properties of concrete of various classes. Methods. Modeling of temperature fields and stresses taking into account specific heat dissipation and properties of concrete. Results: A system of equations is proposed, identical in structure to the strength kinetics equation according to EN 1992-1-1, to describe the kinetics of autogenous shrinkage and heat dissipation of hardening concrete depending on the type of cement according to the hardening kinetics. Modeling of the formation of temperature fields and stresses of a massive flat foundation slab 1.5 m thick was carried out depending on the class of quick-hardening concrete and the specific heat dissipation of cement. It is substantiated that it is insufficient to prevent early cracking by limiting only the «center-top» temperature difference without taking into account the specific properties of concrete. It has been shown that autogenous shrinkage, when dependent on the strength of concrete according to the EN 1992-1-1 equation, can slightly reduce the level of tensile stresses in the early period of concrete hardening of a massive foundation slab. An approach to normalizing the heat dissipation of concrete and cement is proposed in order to limit the stress level under the conditions of the problem considered. The values of the permissible values of the «center-top» temperature difference taking into account the properties of concrete were obtained.
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The production technology of high-performance ceramic stones based on the products of processing of coal dumps

https://doi.org/10.58224/2618-7183-2024-7-4-4
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Abstract
The aim of the research was to study the main properties of coal dumps processing products, their impact on the quality of finished products and the development of a technology for manufacturing process of ceramic stones with high efficiency. Structural features and chemical-mineralogical composition of coal dumps processing products have been studied, their pre-fired and firing ceramic properties have been studied. The raw mass compositions were chosen based on this, along with testing of laboratory samples. The impact of different technological factors on the properties of the final products has been identified and established. The material composition and technological properties of fine, fine and medium fraction materials are shown. A basic classification of the products derived from processing of waste heaps has been conducted based on grain composition, coal component content, and mineralogical and petrographic characteristics. The optimal formulations for raw material mixtures and the manufacturing process for producing large ceramic bricks with an average density below 800 kg/m3 are described. The impact of grinding degree of the waste heap processing products and the firing temperature on the strength of the samples have been established. The incorporation of finely dispersed products from waste heap processing decreases the density and strength of the samples. It is suggested to use semi-rigid extrusion technology for molding these products. Utilizing processed coal waste materials in wall ceramics production will aid in their disposal and enhance the environmental conditions in the area. This research was conducted in Russia at Don State Technical University in Rostov-on-Don. In creating a technology for producing ceramic blocks from screenings of waste heap processing in Eastern Donbass, minimal production costs and high profitability of production are envisaged.
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Modelling of stress-strain state of asphalt concrete layers in pavements taking into account the results of laboratory four-point bending tests

https://doi.org/10.58224/2618-7183-2024-7-4-5
Abstract
Introduction: Fatigue failure of asphalt concrete pavements is one of the most common causes of premature failure of pavements on operational motorways. Modern laboratory equipment and software tools make it possible to comprehensively consider the problem of fatigue failure both for laboratory deformation modes and for operational ones. The aim of the research: a comprehensive study of fatigue fracture of asphalt concretes used in the upper base layer (UBL), lower pavement layer (LPL), and upper pavement layer (UPL) in operational and laboratory deformation modes. Methods: Laboratory studies are carried out on a four-point bending unit in accordance with the methodology of GOST R 58401.11-19. The analysis of operational modes of deformation is carried out on the mathematical model of the stress-strain state of the layered medium. During the stress-strain state analysis, tensile and compressive radial strains at the lower boundary of each asphalt concrete layer were calculated and compared with the deformation modes modelled under operational conditions. Resistance to fatigue failure of asphalt concretes used for the top layer of base course (A32Ot), bottom layer of pavement (A22Nt), top layer of pavement (SMA-16) was investigated using laboratory equipment for four-point bending tests. Results and discussion: Asphalt concrete stiffness modulus reduction curves depending on the number of applied load cycles were obtained. Using the mathematical model, the operational modes of joint deformation of asphalt concrete layers under the load from the design vehicle are investigated.
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Probabilistic analysis of the “multilayer soil – structure” system response to seismic load

https://doi.org/10.58224/2618-7183-2024-7-4-6
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Abstract
Based on the analytical model of a horizontal layered medium, applying the probabilistic formulation, the article presents the results of the investigation of joint work of a structure and multilayer soil bed subjected to seismic loading. The damping properties of soil were taken into account. The authors drew a comparison between the fundamental frequencies of the free vibrations of the “soil - structure” system obtained using the layered medium model and the platform model. By the example of a two-layer soil bed, the dependence of the resonant frequencies of the system on the thickness of the near-surface or buried weak layer was determined.
The results of the analysis of the “two-layer soil - structure” system for seismic loads at various locations of the weak layer were presented. The seismic acceleration of the soil bed was modeled as a stationary random process with a given spectral density. The investigation included an analysis of the amplitude-frequency characteristics, acceleration spectral densities and dynamic coefficients for both the entire system and the individual layers. It was demonstrated that the resonant frequencies of an individual layer being a part of the multilayer system can differ significantly from the resonant frequencies of a homogeneous soil bed with similar dynamic characteristics. A comparison between the dynamic responses of the two-layer soil bed system and a system with the reduced characteristics of the soil bed was drawn at various parameters of the spectral density of seismic load. The intervals of possible values of the resonant frequencies of the system were determined taking into account the random variability of the velocity of transverse waves within each layer.
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Synergistic Integration of Digital Twins and Neural Networks for Advancing Optimization in the Construction Industry: A Comprehensive Review

https://doi.org/10.58224/2618-7183-2024-7-4-7
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Abstract
The object of research is the potential application of digital twins and neural network modeling for optimizing construction processes. Method. Adopting a perspective approach, the research conducts an extensive review of existing literature and delineates a theoretical framework for integrating digital twins and neural network modeling technologies. Insights from the literature review inform the development of methodologies, while case studies and practical applications are explored to deepen understanding of these integrated approaches to system construction optimization. Results. The review yields the following key findings: Digital Twins: Offer the capability to create high-fidelity virtual representations of physical construction systems, enabling real-time data collection, analysis, and visualization throughout the project lifecycle. This allows for proactive decision-making, improved constructability analysis, and enhanced coordination between design and field operations. Neural Network Modeling: Possesses the power to learn complex relationships from vast datasets, enabling predictive modeling and optimization of construction system behavior. Neural networks can be employed to forecast project timelines, identify potential risks, and optimize construction scheduling and resource allocation. Integration of Digital Twins and Neural Networks: Presents a transformative avenue for optimizing construction processes by facilitating data-driven design, predictive maintenance of equipment and infrastructure, and real-time performance monitoring. This synergistic approach can lead to significant improvements in construction efficiency, reduced project costs, and enhanced overall project quality.
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Building life-cycle management by carbon homeostasis potential

https://doi.org/10.58224/2618-7183-2024-7-4-8
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The rapid development of urban areas necessitates a comprehensive understanding of the environmental implications of construction projects, particularly within urban development clusters. This paper discusses the significance of analyzing construction projects, focusing on their carbon potential impacts on the environment. Construction projects are among the largest consumers of natural, material and energy resources, resulting in a carbon footprint that contributes to global climate change. The technological transition to zero-carbon energy sources and low-greenhouse-gas-emitting building materials is setting new trends in the design and implementation of construction projects. This includes achieving a balance between anthropogenic emissions and their uptake by ecosystems - carbon neutrality throughout the building life cycle. As a consequence, the increased focus on global climate change makes reducing the carbon footprint of a building over its lifetime a promising area of research. The novelty of the research is the development of a technology to quantitatively assess the carbon impact of construction projects, facilitating the introduction of low-carbon organisational and technical solutions at all stages of the building life cycle. The methodology of environmental safety management of buildings with high carbon homeostasis for forecasting of comfortable living conditions developed by the authors is based on the systemic representation of the natural-technogenic system of the integrated development of territories in the form of an open dynamic structure. The research is carried out on the basis of the formation tools of the author's factor space of complex carbon impact assessment, ranking and polycriteria comparison of quantitative environmental safety assessment of buildings for selecting the optimal desisions, use of the apparatus of optimisation target setting and carbon neutrality modelling. The implenetetion of the proposed technology can reduce the carbon impact of a project by up to 40% over the building life cycle, maintaining the economic incentive to develop low carbon construction, preventing climate change and ensuring that the construction industry achieves carbon neutrality.
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Digital methods for assessing the quality of the urban environment

https://doi.org/10.58224/2618-7183-2024-7-4-9
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The article considers various methods for assessing the quality of the urban environment, their content, identifies strengths and weaknesses. In addition, the main users of these methods, who is the target audience, who the data is intended for and the possibility of making management decisions based on this data were identified. The article also presents a methodology developed by the authors that allows assessing the quality of urban areas by five main parameters using digital methods based on open city data. This will allow obtaining an objective picture of the state of the urban space and making adequate management decisions. This work is based on an integrated approach to assessing urbanized space, developing universal assessment models that allow correlating different-quality characteristics of city subsystems into a single assessment system, which will allow obtaining a quantitative assessment of the state of spatial indicators of the city. Digital methods of managing the life cycle of urban development systems imply entering a new stage of forecasting, programming and modeling the development of urbanized systems, eliminating serious consequences of urban development errors with large budget losses when implementing poor-quality development scenarios. The priority task of reforming the public authority system is to create a qualitatively new level of public administration efficiency, including in matters of spatial development of territories. The development of a methodological basis for modeling spatial development processes lays the foundation for creating new technological tools, developing digital platforms for spatial modeling of territorial systems development based on a big data system. As a result of the study, the main criteria and indicators of environmental quality were developed. The criteria matrix includes such evaluation blocks as transport and mobility; functionality of space; safety of space; accessibility; improvement of the environment. The evaluation criteria were tested in the Shaksha residential area and refined during a field survey of the city territory.
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