Ways to Improve Construction Efficiency

Technology of arrangement of underground floors in existing buildings using compressed tube concrete piles

2024-01-29T21:37:32+02:00

The article considers the possibility of arranging underground surfaces in existing buildings using the technology of pressed pipe concrete piles. Traditional and innovative methods of performing works are analyzed, which allow to increase the technical indicators of frame and frameless buildings, to restore and increase the operational characteristics of buildings and structures. Special attention is paid to the technology of pressed-in tubular concrete piles and their application in the arrangement of underground floors by building the floor down as an alternative option for measures to increase the load-bearing capacity of the existing object and a promising direction in the reconstruction and modernization of the functional capabilities of buildings. The article is designed to introduce a relatively new method of restoring and strengthening existing foundations and the use of this method in the arrangement of underground floors and is of significant importance for specialists in the field of construction, architecture and design who are interested in expanding the capabilities of existing buildings and structures and optimizing their use in any -what are the functional purposes of these buildings. The use of pressed-in pipe concrete piles in this context can be an important tool for the modernization and improvement of existing facilities and structures, increasing the useful area without increasing the dimensions of the building in the axes on the one hand, and restoring and increasing the bearing capacity of the existing building foundations on the other. This method can help solve a whole niche of new issues, even of strategic importance, including the arrangement of bomb shelters under existing public buildings, such as kindergartens, schools, universities and other public places where bomb shelters are critically important parts of the building from the point of view of public protection today.

Іmperfection of the scientific methodproviding an assessment of the efficiency of investments

2024-01-30T08:42:19+02:00

The article is devoted to issues related to the imperfection of the scientific and methodological tools and the shortcomings of the objective assessment of the economic efficiency of investment projects in the conditions of an acute shortage of investments and a decrease in the efficiency of investment activities observed recently. One of the main conditions for the acceleration of economic growth is the improvement of the system for selecting investment projects for implementation, which is carried out by evaluating the effectiveness of investment activities using a number of indicators that influence investment decisions.

It is indicated that when evaluating the efficiency of complex processes, which includes the investment process, it is generally impossible to unequivocally state the priority of one or another indicator, and it is better to use a system of performance evaluation indicators. Examples are given from the practice of justifications for investment performance evaluation, the analysis of the results of which indicates the imperfection and shortcomings of individual performance indicators and helps to identify new problematic issues of investment evaluation. The essence of individual indicators is revealed and the role of each of them is analyzed, their influence on the correctness of the final decision is substantiated. The research proposes methods of harmonizing intermediate indicators of the net present value using a weighted average generalizing indicator and methods of fuzzy multi-criteria optimization. Although the significant advantage of the last methodical approach, which is manifested by the higher values of its weighting factor when summarizing the partial indicators of NRV, and increases the differences in the advantages of one or another project, but "soft calculations" allow to justify the minimum economic effect that capital investment should provide. Also, a vaguely multiple approach makes it possible to justify the degree of satisfaction of investors' goals in the case of receiving just such a reduced cash flow, instead of the one provided for in the project. Decisions made taking into account the tools for evaluating the effectiveness of investment projects will contribute to the acceleration of the economic growth of our country.

Optimization of logistic processes to enhance productivity of a construction organization

2024-01-29T21:43:08+02:00

This article delves into the significance of logistics process optimization in the construction industry and its direct impact on productivity. Construction companies face unique challenges in managing the flow of materials, equipment, and personnel, making streamlined logistics crucial for efficient project delivery. By examining key strategies and approaches to logistics optimization, this article aims to provide insights into how construction companies can increase productivity and maximize project outcomes. The construction industry is a complex and dynamic sector that relies heavily on effective logistics processes to ensure the smooth flow of materials, equipment, and personnel. In an era where efficiency and productivity are key drivers of success, construction companies are increasingly focusing on optimizing their logistics operations. By streamlining and enhancing these processes, companies can significantly improve productivity, reduce costs, and ultimately deliver projects more efficiently. This article explores the importance of logistics optimization in construction and provides insights into key strategies for achieving enhanced productivity, because optimizing logistics processes in construction is instrumental in increasing productivity and achieving successful project outcomes. By focusing on effective planning, technology adoption, lean principles, collaboration, and modular construction, companies can streamline operations, reduce costs, and enhance resource utilization. The article emphasizes that logistics optimization is an ongoing journey that necessitates adaptability and awareness of industry trends. By prioritizing logistics optimization, construction firms can position themselves for success, deliver projects on time and within budget and ultimately gain a competitive advantage in the market.

Multi-criteria parametric optimisation of the displacement and weight of the shell of a minimal surface with a rectangular plan consisting of two straight lines and two semicircles under thermal and power loading

2024-01-30T07:11:04+02:00

The solution of multi-criteria parametric optimization, where several objective functions are used simultaneously and automatically, is an interesting task for applied and structural mechanics. Modern parametric optimization is performed, because of calculation complexes with additional modules that are programmed in modern programming languages and provide new opportunities for managing calculation methods for spatial structures.

The envelopes of minimal surfaces are very interesting objects of study for optimal design in general and for research in structural and applied mechanics. A minimal surface is a surface in which the median curvature is zero at all points, and thus a minimal surface is a surface of negative Gaussian curvature.

The optimal design of spatial structures is carried out in the main directions, primarily as the main calculations are performed for two groups of boundary states: strength, stability, vibrations, weight, and volume. These are the main objective functions that make it possible to optimize the main characteristics of the structure under static and dynamic external loads when studying the stress-strain state.

Parametric optimization is understood as the process of achieving an extreme goal under the assumption of stationarity of the extreme characteristic of the optimization object in the plane of the minimum surface envelope, which is limited by its geometry and input and output parameters. In this case, the optimization object can either actually exist or be a mathematical model. Methods and algorithms of parametric optimization play an important role in the general mathematical method of design calculation.

A multi-criteria parametric optimizations was used to reduce the weight of the shell. The Mises stresses meet the limit of 260 MPa. It should be noted that the theoretical optimum of the objective functions at the point of intersection of the two objective functions is 260 MPa, which is a limitation, we can conclude that despite the fact that the two objective functions conflict, at the point of optimum, they work quite effectively in this problem statement.

Methods of standardizing processes of construction of monolithic building structures

2024-01-30T07:20:24+02:00

The existing standardization systems of labor processes in the construction industry are considered. During the last twenty years, there has been significant progress in the development of construction technologies, which is associated with the rapid development of materials, structures and means of mechanization. BIM design technologies and management of construction projects are developing very quickly. There is a lag in the development of construction process standardization systems, which holds back the creation of electronic standards databases. The importance of rationing the time for the execution of construction processes is increasing. The existing systems of standardization of construction processes have a number of shortcomings and require changes in the approach to standardization. The breakdown of processes into components should be finer. The standards should allow changes to be made to the project in accordance with the introduction of new construction technologies, materials, mechanisms, and equipment. The main shortcomings of the existing standardization systems are considered on the examples of the installation processes and dismantling of floor formwork. The analysis resulted in the statement that the existing norms do not correspond to the principles of variant design of technological processes, restrain the design development and management of construction projects.

The foreign experience of standardizing processes in mechanical engineering, as in the industry that is a level above construction, is considered. There are certain advantages of the system for the production processes standardization of factory-made products, which allows some approaches to be used in the standardization of construction processes. One of the ways to solve the problems of normalization of construction processes is the possibility of combining normalization methods with the transition to the definition of time norms and norms of labor costs of smaller elements of technological processes, such as actions, sets of actions, operations. For this purpose, it is proposed to combine the elements of the method of microelement standardization with the method of developing maps of labor processes, which will allow to develop a new methodology of integer standardization of the processes of erecting monolithic buildings and structures.

The factors of external environmental impact on a construction project

2024-01-30T07:25:21+02:00

The article highlights the factors of environmental impact on a construction project. It is determined that the success of the development and implementation of a construction project largely depends on the external environment and the quality of work of the participants involved in the process of development and implementation of a construction project. It is determined that environmental factors are divided into microenvironmental factors (in which a construction project is directly developed and implemented) and macroenvironmental factors (which include the general economic environment of the State and the region in which the construction project will be implemented, current legislation, tax system, credit policy, financial market conditions and the construction services market). It is found that modern building design is considered as a relatively independent step in the process of creating new socio-technical systems and processes, a kind of chain between research and production. It was found that each construction project has a list of specific goals and constraints. It is established that the practical experience of developing and implementing a construction project shows that attempts to reduce the cost of a project usually lead only to additional costs, which in some cases requires redevelopment of the construction project. The key stages of development of design and estimate documentation for a construction project are highlighted. It is determined that the effectiveness of a construction project reflects whether the construction project meets the goals and interests of the participants. The author finds that development and implementation of construction projects requires cooperation with state and local authorities, and that an important prerequisite for successful implementation of construction projects is the ability of local authorities to effectively fulfill their powers to provide quality services to developers. It is established that before starting construction, it is important to comply with legal and regulatory requirements and take into account the significant potential risks of construction contracts.

Construction life cycle assessment methods and their key features

2024-01-30T07:39:31+02:00

The article examines the methods of assessing the life cycle of construction, as well as defines their key features and role in the strategic management of construction projects. Key features include a comprehensive approach to assessing the impact of construction projects on areas such as the economy, environment and society. The application of life cycle methods in the construction industry is related to: the assessment of the effectiveness of the implementation of construction objects and the need to work out the issue of financial planning and budgeting, taking into account not only the costs of construction, but also the costs of operation and disposal; with the analysis of investment risks, which are extremely important in solving socio-economic issues; implementation of mutually beneficial cooperation schemes between state structures and the private sector; on the attraction of foreign investments in the economy of the state. Analysis of specific construction materials and technologies at different stages of the life cycle can serve as a basis for developing recommendations for choosing materials with a lower environmental impact. The integration of life cycle assessment (LCA) methods with other sustainability and environmental impact assessment methods allows creating more comprehensive approaches to the analysis of objects, services or projects. The results of the research can be used in the development of practical recommendations for builders, designers and other industry participants regarding the use of environmentally friendly materials, technologies and construction methods. The creation of training schools and conditions for the successful implementation of life cycle assessment technologies in the construction industry is extremely important to ensure effective and sustainable development.

Methodology for designing technology for restoration of architectural monuments. Current state and prospects for development

2024-01-30T07:43:27+02:00

The article presents the results of the generalization of the past development of the methodology of designing technologies for the restoration of architectural monuments with an assessment of the current state and development prospects. For the first time, the author proposed the division of the past development of the methodology of designing the technology of restoration processes into four main periods, which collectively reflect the general history of the development of restoration as a construction business, compatible with the development of the main concepts and principles of restoration, namely: the first period - the development of the initial foundations of the methodology organizationally - technological design based on the generalization of original practical experience and theoretical principles of restoration of architectural monuments; the second period - the formation of modern foundations of the methodology of organizational and technological design of restoration technology, including its natural and scientific essence, topology and methods of decision-making, taking into account the accepted principles of restoration of architectural and historical monuments, decisions of the World Venice Congress of restorers; the third period - implementation and adjustment of the basics of information and analytical modeling of organizational and technological solutions regarding the design conditions of restoration of architectural and historical monuments; the fourth period - the formation of modern informational and numerical methods of organizational and technological design with the presentation of design results in the form of a multidimensional parametric image. It has been established that the selection of rational technological solutions for the implementation of restoration processes is carried out today, as well as the general technology of construction production - on the basis of the variability of the choice and multi-criteria technical and economic analysis. For the first time, the main reasons for the imperfection of the elements of the methodology of designing restoration technologies are established, which are due to its phenomenological immaturity and a significant amount of borrowings from the general technology of construction production regarding the main provisions of the theoretical foundations and logic of the theory.

Introduction to the theory of sustainable operation of technological systems for building reconstruction

2024-01-30T07:52:51+02:00

The article outlines the main provisions for increasing the stability of the functioning of technological systems in complex and changing conditions of reconstruction, accepted as a system of conceptual, theoretical, and methodological foundations for the formation of their morphological appearance as adaptive dynamically transforming technological systems. Increasing the stability of the functioning of technological systems in complex and dynamic conditions of reconstruction is ensured by the implementation of strategies: A-strategy. Reduced dynamics of environmental conditions; B-strategy. Ensuring an increased level of homeostasis of the technological system in relation to the external environment and the dynamics of its states. The A-strategy is implemented at the stages of preparation for reconstruction and in the process of its implementation, and the B-strategy is implemented by the formation of a technological system that ensures its invariance with respect to changes in the states of the external environment and which is carried out by increasing the functional inertia of the system, functional and structural redundancy. The author called such systems adaptive dynamically transforming technological systems. Adaptive dynamically transforming technological systems are endowed, on the one hand, with the properties of astatic systems – as systems with variable morphology, capable of detecting purposeful adaptive behaviour while maintaining internal balance, and, on the other hand, with the properties of static systems – as high-performance specialized systems with states. Astatic properties ensure optimization of costs for transforming the morphology and function of a technological system, as well as limiting system states to the minimum possible level, and static properties optimize differential effects on a variety of characteristic production situations. The use of adaptive dynamically transforming technological systems allows us to resolve the fundamental parametric contradiction in building reconstruction technology – highly efficient and sustainable implementation of non-stationary construction processes in complex and changing conditions of building reconstruction.

Classification of sliding formwork systems

2024-01-30T07:57:21+02:00

The article discusses modern sliding formwork systems, which are different from other types of formworks in that they can be moved during the construction of structures without the need for intermediate stages of formwork installation and removal. This, and the possibility of using a high level of process automation, allows to increase the rate of monolithic construction and significantly reduce the number of working seams, which in turn increases the structural reliability and reduces the complexity of formwork operations. The development of constructive solutions for sliding formwork systems has created a significant range of varieties of these systems, which allows expanding the range of applications for sliding formwork.

Based on the analysis of existing sliding formwork systems, their classification is proposed according to the factors that influence the constructive solutions, namely: constructive solutions of forming elements, constructive solutions of the supporting part of the formwork system and the mechanism of movement of the formwork system in the process of constructing a monolithic structure. It is proposed to classify sliding formwork systems according to the following features of the structural solutions of the forming elements, namely: the size of the formwork panels; the shape of the surface of the forming elements; the location of the forming elements in relation to the structure being constructed; the geometry of the forming elements; the method of fixing the forming elements in relation to the surface of the structure being constructed; the material of the surface of the forming elements in contact with the freshly placed concrete mixture. According to the constructive solutions of the supporting part of the formwork system, it is proposed to consider the following features: the method of supporting the formwork part; the construction of jacking frames; the location of jacking rods. According to the mechanism of movement of the supporting part of the formwork system, it is proposed to distinguish the following features: elements that move in the process of raising a monolithic structure; direction of movement of the sliding formwork system; types of jacks used to move the formwork system; control system for moving the sliding formwork system. The presented classification takes into account technical parameters and functional properties, which contributes to a better understanding of the choice of the best type of formwork for specific construction tasks. The results of the study may be useful for engineers, architects and other construction industry professionals interested in improving the efficiency and quality of construction projects.

The influence of the period of collection of flows in industrial construction without using additional labor resources

2024-01-30T08:03:07+02:00

In the non-rhythmic flow construction of industrial facilities, there are processes with a reserve of unused labor resources on works and grabs, which affect the term of work (the period of deployment of flows). The analysis of non-rhythmic works showed that they have works with a period of curtailment of flows of greater than the smallest value and they have a reserve of unused labor resources, but do not affect the terms of execution of works.

It is proposed to reduce the duration of non-rhythmic flow works on technologically identical processes by using unused labor resources on works with an increased flow curtailment period on interdependent grippers.

Performed preliminary studies showed that interdependent grabs for parallel work are determined by a rank matrix with priority on the OVRR front. These jobs with increased flow deployment period showed that redistributing work volumes between two jobs reduces the duration of jobs. In previous studies, the redistribution of the volume between these two works has an abstract nature without determining the technological homogeneity of the two works. The redistribution of non-rhythmic work volumes is forged in it into technologically identical types of occupations. For processes with an increased period of curtailment of flows, it is proposed to balance two jobs by a parallel method of performing work on technologically identical types of work without the use of additional labor resources.

Optimizing the reduction of the construction period involves the use of parallel methods on two technologically identical works with an increased flow curtailment period. The example shows examples of balancing two jobs by using special and universal (excavator) machines with specialized specialists or complex crews. Technical and economic indicators were determined for the performed optimization.

Assessment of the technical acceptability of innovative construction products: environmental and economic parameters and requirements

2024-01-30T08:17:15+02:00

The article examines the process of assessing the technical acceptability of construction products that embody innovative properties. The evaluation procedure for such products should be carried out on a dual scale – taking into account both environmental and economic parameters to ensure a full understanding of the viability of the product.

The environmental parameters and environmental impact considered in the assessment cover a range of factors, including life cycle assessment (LCA), carbon footprint and adherence to circular economy principles. There is especially little assessment of the life cycle flow of a building, after which life cycle pricing provides a holistic detection, assessing the complex impact of building products on the environment. Carbon considerations focus on the total carbon emissions associated with production, transportation and installation, which contribute to broader sustainability goals. The principles of the circular economy guide the evaluation towards more efficient use of resources and reduction of waste, emphasizing the importance of recyclability and durability. At the same time, the player’s economic parameters provide a key role in determining the technical acceptability of innovative construction products. Economic viability is assessed through factors such as economic efficiency, life cycle cost and overall economic sustainability. The assessment covers the long-term economic prospects and demonstration economics associated with innovative products, ensuring their feasibility within the economic constraints of construction projects.

The study emphasizes the relationship between environmental and economic parameters, notes that technical acceptability has the effect of not only technical and environmental constraints, but requires a balanced assessment of all dimensions. The integration of these parameters is consistent with the industry’s broader transition to sustainable and economically viable construction methods.

Outlines requirements for technical acceptability, emphasizing the need for validation of regulatory standards, certification and transparent documentation, using an integrated approach involving stakeholders, industry experts and regulatory bodies to reach consensus on technical acceptability criteria for innovative construction products, contains a detailed study of technical acceptability assessment, recognizing the key role played by environmental and economic parameters. Incorporating both dimensions, the evaluation system seeks to recognize acceptable innovative construction products that not only meet technical standards, but also promote sustainable and economically viable construction practices.

Increase of bearing capacity concrete elements of building structures on compression

2024-01-31T07:07:42+02:00

The article describes the results of determining the influence of ultra-small doses of surface-active substances on the strength of artificial stone obtained from a mixture of nanopowders. the purpose of the work is to determine the effectiveness of the use of surface-active substances in ultra-small doses during the hardening of a mixture of cement nanopowder and calcium carbonate and gypsum nanopowder. The methodology of conducting experiments includes the following methods: analysis of studies on the use of nanopowders and surface-active substances; standard methods of testing building materials; comparative analysis; systematization and generalization of foreign and domestic experience. As a result of the research, the influence of surface-active substances applied in ultra-small doses on the strength of the artificial stone formed as a result of the hardening of nanopowder of calcium carbonate and cement was determined. It has been proven that in this case, the action of ultra-small doses of surface-active substances consists in reducing the number of open pores in the cement stone. Experimental studies have confirmed that molecules of surface-active substances, such as hyperplasticizers or others, significantly change the pH of the water used to make concrete. Increasing the mechanical strength of the obtained artificial stone allows replacing part of the cement nanopowder with a cheaper mineral nanopowder. It was established that an increase in the water-cement ratio in the mixture of nanopowders leads to an increase in the effectiveness of ultra-small doses of surface-active substances in the formation of compressive strength. The highlighted scientific materials became the starting point for understanding the researched issue. The effect of ultra-small doses of surface-active substances on the strength of artificial stone obtained from a mixture of nanopowders was identified and substantiated. The results of the research can be used in the production of concrete and reinforced concrete products and structures.

Technical inspection of buildings and construction: modern approaches and solutions

2024-01-31T07:12:52+02:00

In this article, the authors try to outline modern technological solutions that are used in the practice of performing technical inspections of buildings and structures, as well as to analyze the leading technological achievements in the theory of performing these works.

During the last year, as a result of military actions caused by the aggression of the Russian Federation, about 150 thousand buildings and structures were destroyed or damaged in Ukraine, including more than 17.5 thousand multi-apartment residential buildings.

Damaged buildings and structures require a technical inspection to determine their further repair, reconstruction or controlled dismantling and new reconstruction.

In Ukraine, the process of restoring damaged social, economic and residential buildings is already underway. Monitoring and periodic inspection of the condition of restored buildings are important parts of the facility management system, as it allows timely detection and response to any damage or deviations from normal functioning, which can ensure safety and extend the service life of the structure.

The scope of work on technical inspection and their special conditions determine the need for effective performance of work with the possibility of applying modern approaches and solutions.

Information is given about the main authors of scientific research on this topic, the names of foreign companies that are the drivers of the market of modern building inspection technologies are indicated.

The main commonly known methods of inspection of buildings and structures are analyzed, their types are systematized. Among modern technologies, the main attention is paid to the use of unmanned aerial vehicles, as such, which have become widespread in the developed countries of the world. The advantages of using this technology are indicated, as well as the problems accompanying the practical commercial use of unmanned aerial vehicles during the technical inspection of buildings.

Prospective topics for further research in this field of science are proposed, in particular, to develop a methodology for the economic feasibility and effectiveness of using one or another innovative method of examination.

Enhancing resource management in building restoration through the use of Artificial Intelligence

2024-01-31T07:23:45+02:00

In construction, modern technologies are becoming a key factor in achieving resource conservation and improving efficiency. The application of artificial intelligence not only reduces resource consumption but also creates opportunities for optimizing the design processes and organizing construction production. Monitoring systems for the construction process, along with the implementation of advanced IT technologies in the construction industry, contribute to increased accuracy and speed of work execution. This innovative approach to construction not only promotes resource conservation but also creates essential conditions for the sustainable development of the industry.

In the construction industry, where a traditional approach prevails, the implementation of artificial intelligence poses a challenge due to the absence of prior practice. As this technology is cutting-edge, a detailed study and practical testing are necessary to elucidate its potential advantages in the construction process. In the future, with the advancement of the industry, the use of artificial intelligence in construction could become a key factor in improving resource conservation, calendar planning, optimizing processes, and refining project management strategies.

The purpose of this article is to develop an understanding of the impact of artificial intelligence on calendar planning and its potential application in post-conflict city rebuilding. In contemporary times, artificial intelligence is becoming an increasingly crucial tool in various fields, including project management, industry, and the economic components of post-crisis situations. Its high potential can contribute to addressing issues related to the reconstruction of cities affected by conflicts. Intelligent algorithms can effectively analyze and optimize calendar plans, considering various factors such as available resources, residents' needs, infrastructure, and more. This will enable the development of precise and efficient recovery strategies, ensuring optimal resource utilization and maximum social impact.

The influence of hydrogen on the resistance to the formation of cracks in welded joints of water supply pipelines

2024-01-31T07:29:06+02:00

The existing scientific and practical studies of the influence of hydrogen on the parameters of crack resistance are characterized by uncertainty and contradiction, the lack of clear ideas about the mechanism of the initiation and propagation of cold cracks, and therefore there are no balanced approaches to combating the formation of cracks during the long-term operation of pipelines, and therefore additional studies are needed. It was established that with an increase in the content of diffusible hydrogen in the deposited metal, the resistance to its brittle destruction decreases sharply. Thus, with a hydrogen content of 8,1 cm³/100g in the deposited metal and a cooling rate Wohl = 4,0 ⁰С/s, the crack initiation work Azt = 1,5 J, and at 1,5 cm³/100g, the value of Azt increases to 17,6 J, that is, more than 11 times. When the hydrogen content is higher than 5,0 cm³/100g, and Wohl = 55 ⁰C/s, the Azt value is practically zero. It is shown that with an increase in the hydrogen content in the weld, the work of crack propagation also decreases Art. Thus, with a hydrogen concentration of 1,0 cm³/100g for a welded joint on steels 09Г2С and 17Г1С at Wohl = 4.0 ⁰С/100g, the value of Art = 48,5 J/cm², and when its content increases to 8,0 cm³/100g, the work of Art decreases to 18,5 J /cm², i.e. approximately 2,7 times. A decrease in the air temperature during welding to -30...-40 ⁰С and an increase in the concentration of dissolved hydrogen in the weld seam to 5–8 cm³/100g lead to an increase in the critical brittleness temperature by approximately 40–50⁰С. Plastic deformations that inevitably occur in welded joints and structures, according to their nature of occurrence in the process of the technological cycle of manufacturing and operation of a welded structure, can be divided into the following groups: a) initial deformations in the base metal, which depend on the method of obtaining and processing the metal, foundry, powder metallurgy, pressure (rolling, stamping, forging); b) deformations occurring during procurement operations and assembly, cutting, straightening, bending, rolling, fixing on assembly devices; c) welding deformations arising as a result of the thermal deformation cycle of welding; d) technological deformations; d) operational deformations that may occur during operation as a result of local overloads, loss of stability, etc.

Setting the parameters of the burnout rate of samples of flame-retardant cellulose-containing materials

2024-01-31T07:35:14+02:00

The paper deals with the issues of fire protection of cellulose-containing materials, in particular sailcloth and wood. The combustion process of materials is influenced by their physical properties: density, thermal conductivity, heat capacity, as well as a number of other factors, such as humidity, the ratio between the reacting surface and the volume or mass of the material that is ignited, its position in the heat flow, air flow velocity or draft, and the degree of heat concentration during combustion. The description of the behavior of fire retardants and coatings, including swelling coatings, at the time of formation of the insulating structure is a separate and complex task. In general, it covers both stages of the thermal protection process: as a rule, the decomposition of flame retardants under the influence of temperature with heat absorption and the release of non-combustible gases, and subsequently the swelling of the coating formed during fire protection. Therefore, there is a need to study the conditions for the formation of a barrier to thermal conductivity and to establish the mechanism of fire protection from layer to layer of coke. In this regard, a study of the fire protection process during the operation of the fireproof coating was carried out. As a result of the research, it was found that the burnout rate of fire-retardant cellulose-containing materials depends on four parameters, namely, the parameter characterizing the intensity of flame combustion development (α, s^-1), the intensity of suppression of combustion reactions due to fire protection of materials (γ, s^-1), the intensity of material combustion at the initial moment of time (ω₀, kg/(m²·s²)), and the initial burnout rate (u₀, kg/(m²·s)). The dependence of the extreme moment of time was obtained, in which the mass burnout rate of a sample of fire-protected material is minimal (the burnout rate of wood samples treated with fire-protective agents (compared to untreated ones) decreases by 3.6 times), which makes it possible to more effectively determine the effect of impregnating compositions on the burning of samples of cellulose-containing materials.

Organization of the integrated management system in the construction industry

2024-01-31T07:42:20+02:00

The scientific article reveals the problems of finding innovative approaches to solving problems related to the organization of an integrated management system in the construction industry. Promising trends of integrated management in the construction sector, which are focused on the flexibility and adaptability of management systems to modern conditions, are studied. The ability to respond quickly to changes in market conditions and customer requirements is becoming key to the success of construction projects. The urgency of the problem of finding rational solutions for the organization of the integrated management system in the construction industry is indicated. The paper highlights the problems of organization of the integrated management system in the construction hall. Construction projects often come with risks, such as changes in the project, unforeseen circumstances, and technical complications. Integrated management systems must meet the challenges of risk management and provide flexibility in solving problems. Grounded prospects and opportunities for using an integrated management system that allows construction enterprises to be flexible and adaptable to changes in the internal and external environment. This is especially important in the face of rapid technological changes and volatile market conditions. As a result of the analysis, opportunities for the introduction of innovative technologies and methods in the construction industry have been identified. The integration of advanced solutions allows us to improve construction processes at all stages. The results of our research revealed the basic principles of applying an integrated management model under risk conditions for quality control modules in construction, based on the concept of dynamic systems. Therefore, we consider it expedient to introduce an integrated model risk and quality management in construction, and this requires further scientific research. The proposed method allows to harmonize the processes of quality management and risk management, taking into account the criteria of project efficiency, contributing to the avoidance of conflicts between the requirements for the quality of the construction object and the level of acceptable risks. In addition, this approach aligns them with the efficiency requirements for the developer. It is determined that the principles of using the integrated model of quality management in the face of risks include the principle of complementarity and the principle of identity of the management process. This made it possible to identify management modules that correspond to the concept of construction quality management in the face of risks as a dynamic system.

Analytical platform for the process of managing the flows of secondary resources in the construction industry

2024-01-31T07:45:46+02:00

The scientific article reveals the problems of finding innovative approaches to solving optimization problems related to the management of flows of secondary resources-materials for the implementation of construction processes. Promising trends of logistic concepts as an important tool for effective management of flows of secondary resources in the construction sector are studied. The urgency of the problem of finding rational solutions in managing the flows of secondary resources (materials) in the context of construction Processes. The publication highlights the main regularities of functioning of the system of integrated management of waste flows (SKUPV) in the construction industry and identifies the practical possibilities of their implementation. A scheme for finding optimal solutions based on the principles of logistics systems is outlined. The prospects and possibilities of using construction waste as secondary resources-materials are substantiated. As a result of the analysis, it was found that building production systems, while developing, have undergone an optimization evolution and reached a new, progressive level of flow management. The proposed approach assumes that material and energy resources are not concentrated in the final product, but are accumulated in the form of additional products – raw materials and energy, which are reused in the recycling process in their own production or sold in secondary markets. The results of the study made it possible to reveal the definition of the system of integrated management of waste flows (ICMS) of the construction industry, which takes into account the key components of the economic effect. It is an indisputable fact that the waste of the construction industry has a significant potential to become a secondary raw material, the use of which after processing (as secondary products) according to certain technologies (which are becoming more and more in the context of the search for environmentally friendly organizational and technological solutions), allows to reduce the cost of construction projects and at the same time reduce the load on landfills, to exclude the uncontrolled increase in unauthorized landfills. It should also be noted that as a result of the processing of waste from the dismantling of structures using advanced technologies based on the principles of environmentally oriented innovative development, the efficiency of the use of materials increases by reducing production costs.

Dispersed-reinforced concretes and mixtures with mineral and organic fibers

2024-01-31T07:49:31+02:00

Problem Statement and Relevance. The article addresses the development and research of composite materials reinforced with discrete fibers of low (organic) and high (mineral) elastic modulus, corresponding to E = 400-1000 MPa and E = 40000-60000 MPa, respectively. The use of discrete fiber reinforcement technology is considered a solution to enhancing the strength and reducing deformation characteristics of materials based on mineral binders. In the United States, Japan, and Western European countries, the production of composites reinforced with discontinuous fibers of organic and mineral origin is well-established. In France and Germany, scientific and industrial organizations have been established for the development of reinforced composite materials for aerospace, engineering, and construction industries. The introduction of discrete reinforcement technology in the production of reinforced concrete products simplifies the manufacturing process, especially for thin-walled structures. Calculations show that 1 ton of discrete fibers can replace up to 5 tons of steel. The article aims to develop and discover composite materials reinforced with discrete fibers with low and high modulus. Conclusions. Based on the results, the hypothesis of expanding the range of physical and mechanical properties of composite materials based on mineral binders by introducing a mixture of discrete organic and mineral fibers with high and low modulus is relevant and promising in the full development of construction material production technology. Organic fibers with a modulus of elasticity of 400-1000 MPa increase bending strength and dynamic load resistance (impact toughness) to 8-12 MPa and 20-29 kJ/m2, respectively. Discrete fibers of mineral origin with a modulus of elasticity of 40000-60000 MPa increase tensile strength by 2.5-3 times and compressive strength by 1.2-1.25 times. Impact strength and bending strength significantly exceed those of non-reinforced composites, reaching values of 38-50 kJ/m2 and 12-14 MPa. Fiber parameters depending on matrix properties and composite design indicators. In our studies, fiber length ranges from 18-51 mm with organic fiber content of 0.6-1.2% and glass fiber content of 4.1-4.5%. These parameters allow increasing tensile and compressive strength of composite materials reinforced with a fiber mixture by 2.2-3.0 and 1.2-1.3 times, respectively. A promising method is the preparation of samples and products by spraying (shotcrete method), achieving effects at lower parameters. The technology of applying coatings by spraying (shotcrete method with the CETI-487B ejector-type machine) includes a working mode selected by shotcreting a portable metal shield: the amount of shotcrete mixture supplied, water, compressed air pressure, consistency of the solution, distance from the installation to the workplace, and from it to the shotcreting surface in vertical and horizontal directions. In the manufacture of samples, this method allows introducing up to 8-10% of discrete fibers (by the mass of the binder) compared to 3-4% by conventional forming methods.

Methodological approaches to assessing the level of digitalization of the construction site

2024-01-31T08:05:11+02:00

The article explores the important area of assessing the degree of digitization of construction sites. As the construction industry undergoes digital transformation, understanding and quantifying the degree of digitization becomes key for stakeholders, including project managers, contractors and technology providers.

VIM technologies are an actual area of research. due to the growing importance of digitization in construction, the recognition of its potential to improve efficiency, collaboration and overall project results, there is a growing need for a systematic and comprehensive methodology to assess the level of digitization, taking into account the multifaceted nature of construction projects.

The methodology proposed in the paper covers various aspects of digitization, from the implementation of Building Information Modeling (BIM) and the use of digital tools to the integration of Internet of Things (IoT) devices on site, a structured methodology and framework that includes Key Performance Indicators (KPIs) or metrics is proposed to measure the digital maturity of construction activities.

The study draws on existing literature and case studies to support its methodological approaches, providing a synthesized view of best practices and successful implementations in the construction industry, including references to specific projects that have effectively used digitization to achieve better project outcomes, cost savings or accelerated timelines.

In addition, challenges and barriers related to the digitization of construction sites, issues related to technology adoption, workforce training, data security and digital tool interoperability are explored. Addressing these issues within the framework of the proposed methodological approaches will increase the practical applicability of recommendations, informed decision-making, optimization of resources and the overall progress of the construction industry towards more technological and sustainable practices.

The study contributes to the field of construction management and technology by offering a structured and methodical approach to assessing the level of digitization on construction sites. By combining theoretical foundations with practical research knowledge, it can serve as a reference for professionals and researchers seeking to achieve digital transformation in the construction industry.

SWOT-analysis of digital maturity of construction participants

2024-01-31T08:11:43+02:00

The article is devoted to a comprehensive SWOT analysis of the digital maturity of construction participants. The application of the SWOT methodology, which covers strengths, weaknesses, opportunities and threats, is also relevant to developers, contractors and designers, shedding light on the complex dynamics in each group of participants, after the construction industry experiences a profound digital transformation,

The article reveals the strengths of development companies that have begun the process of digital transformation, emphasizing innovative project visualization and financial modeling. The used digital tools enable the developer to make an informed decision, optimizing the evaluation of project invalidity. However, the assessment also acknowledges some weaknesses, such as the limited adoption of Building Information Modeling (BIM), underlining the importance of overcoming the backlog of change to fully utilize digital methodologies.

For contractors, the article recognizes their strengths in digital project management and on-site technology integration that improves efficiency and real-time monitoring. However, it highlights the weaknesses of limited BIM integration and skills gaps among the workforce, creating challenges for seamless collaboration and optimal use of tools.

The article highlights the strengths of projects in the adoption of design parameters by Ukrainian project organizations and promotion of digital cooperation. However, this does not address current weaknesses such as interoperability issues and skills gaps in sustainable design, emphasizing the need for streamlined workflows and ongoing skills development.

The article also talks about ways of growth and possibilities of digitalization for each group of construction participants. Developers are encouraged to invest in data-driven decision making and a collaborative platform, while Contractors are encouraged to explore advanced construction technologies and prioritize a collaborative platform. Designers are offered opportunities for virtual design and construction (VDC) and the integration of Internet of Things (IoT) devices into their design processes, promoting innovation and efficiency. The article also examines existing challenges that construction participants may face. Developers may face threats related to unfair competition and data security issues. Contractors must overcome threats related to competitive pressures and project support, while designers may face challenges such as competitive disadvantage and resistance to Building Information Modeling (BIM) methodologies.