Technological Process Of Construction Research Articles

FEATURES OF THE PROCESS OF LOADING AND TRANSPORTATION OF HOT ASPHALT CONCRETE MIXTURE. UKRAINIAN EXPERIENCE

Depicted in the Article are two stages of technological construction processes for asphalt concrete courses, namely: loading and transportation of asphalt concrete mix. As regards the loading, presented in the Article are two versions of discharging directly into dump body of dump truck or into storage hopper. Mentioned are the advantages of storage hopper usage, as well as the variety of such facilities and the storage time for asphalt concrete mix inside them. Described is the preparation procedure for a dump body of dump truck prior to loading (cleaning, lubrication). Explained are both the proper and improper schemes of loading, as well as the visual signs of asphalt concrete quality after discharging. Described is the right way to protect the asphalt concrete mix against cooling in dump body of dump truck, as well as the proper distance and allowed time-interval for transportation, possible problems occurring during transportation, expediency of using re-loaders for discharging the mix into the receiving hopper of asphalt paver

Dry mixes on gypsum and mixed bases in the construction of low-rise residential buildings using 3D printing technology

3D-printed building construction technology is developing in most countries, such as France, China, Russia and others, and the dry mixes and equipment used are being improved. The development of 3D-printing construction technology is dictated by its many advantages: architectural diversity, speed and automation of the technological process of construction of buildings and structures with a noticeable reduction in the cost of production. However, there are a number of problems of this technology that are waiting for optimal solutions. The paper proposes solutions to two such problems: firstly, the choice of mixture with gypsum and gypsum-cement binders, ensuring the continuity of the 3D printing process of the building and allowing the construction of buildings up to three floors with sufficient safety margin, high seismic stability, as well as with good heat and noise insulation; secondly, the design of buildings with a rational structural and technological solution of the roof and floor, allowing the interface of these structures with load-bearing printed walls. Different compositions of dry mixes were tested in a series of field tests of large-sized wall blocks made with the use of a construction 3D-printer and filled with especially light porous expanded claydite, expanded clay concrete or heat-insulating foam gypsum with subsequent testing on press equipment of increased load-carrying capacity (with determination of bearing capacity and deformability of the large-sized block). When designing low-rise buildings, erected by additive technology, as an optimal design of floors, it is proposed to use frame-monolithic beam structures made of metal thin-walled steel galvanized profiles, filled with foam gypsum mix, providing heat and noise insulation and covered with a thin layer of high-strength self-leveling gypsum mix, providing the necessary structural strength of the floor and, accordingly, the minimum load on the foundation.

Analysis of studies of stationary tower cranes under wind loads

Loading and unloading operations are an integral part of the technological process of construction. Cranes of various types are mostly used to perform these works.
 In modern industrial and civil construction, tower cranes of the stationary type are widely used, which are used in the construction of various types of structures and buildings.
 Today, it is impossible to imagine a panorama of a city or a fairly large rural village without the upward, light openwork silhouettes of tower cranes. They are clearly visible against the background of new residential buildings, wherever progressive changes are taking place, where construction is underway. More than 200,000 tower cranes are used on construction sites in the country today.
 But when using tower cranes, special attention must be paid to their operation in adverse conditions, because they are mechanisms of increased danger.
 One of the important factors in the unfavorable conditions during the full-scale Russian invasion of Ukraine was the shock waves that arise as a result of missile strikes. These shock waves, in turn, cause air pressure and oscillations on the Earth's surface and cause certain seismicity.
 To ensure trouble-free operation and increase the reliability of tower cranes, it is important to take into account dynamic loads, which are several times greater than static loads, when calculating structures and components of their working equipment.
 Ensuring the stability of stationary tower cranes, especially in the conditions of martial law, is one of the important theoretical and practical tasks. The most important aspect of solving this problem is ensuring stability under the conditions of air shock waves, which cause the effect of dynamic loads on the metal structures of the crane.

Tolerances calculation for construction works and geodetic control during erection of reinforced concrete foundation columns for steel structures of thermal and gas-material pipeline overpasses

The purpose of the publication is to analyze the methods of calculations of accuracy of construction works and geodetic control of erection of reinforced concrete foundation columns for overpass steel structures of thermal and gas-material pipelines of oil refineries. For this purpose, a calculation methodology is considered, which takes into account operational technologies, including construction works and geodetic control, during the erection of the above-mentioned structures. The obtained results show that in order to ensure the standardized limit deviations of construction works, interrelated reasonable accuracy standards in the erection of structures are required, taking into account the average weighted average errors of geodetic control. In regulatory documents for the erection of structures are given accuracy standards (limit deviations) on their final position, and on geodetic control are given without taking into account the technological processes accuracy indicators of construction works. Setting the liability indicator of structures by purpose, we are establishing a confidence probability of ensuring the construction accuracy of the structure. To analyze the construction works and geodetic control accuracy we used the following methods: equal and negligible influence of deviation on the final position of structures and the method taking into account the accuracy of construction’s technological processes. In this publication examples of error calculations using the above mentioned methods are given. It is established that the most justified tolerances for structures erection are obtained when the method is applied taking into account the accuracy of their construction technological processes (by the accuracy indicator of technological process of construction works the limiting errors of geodetic control are established).

Analysis of the operating conditions of contactless seals during reciprocating motion of plunger pairs of drives of construction machines

Hydraulic drive of construction machines and mechanisms used in technological construction processes is increasingly being used in the construction industry. This is due to the small weight and small overall dimensions per unit of drive power, insignificant inertia of moving parts, good dynamic characteristics, ease of reversing, smooth running, durability of mechanisms due to self-lubricity, simplicity and reliability of operation. The reliability of the hydraulic drive of construction machines is largely determined by the effectiveness of the lubrication system of contactless seals of movable joints. The stability of characteristics, efficiency and safety of operation of mechanisms and hydraulic drive, in particular, depends on the quality of lubrication of sliding surfaces. In order to improve the quality and durability of the hydraulic drive for a certain range of plunger diameters and pressure drops in hydraulic units, the most rational means of combating dry friction forces is a slit non-contact seal.

Construction solutions and calculation methods of horizontal protective shields for tunnel-type structures

The article considers features of creating horizontal protective shields made of steel pipes for construction of tunnel-type structures in a closed manner. Types of horizontal protective shields and methods of their construction are analyzed. Variants of modern tunnel structures arranged in difficult geological conditions with the use of lining from large diameter pipes along the perimeter of the entire structure are given. Factors influencing the choice of a rational shield shape and an appropriate design model for solving the problem of the stress-strain state of the soil body weakened by a horizontal cavity of a closed type are taken into account, considering various options for propping and external influence on the soil body under studyThe obtained value of settlement of the upper layer of the support also depends on the dynamic loads from the railway tracks, but does not take into account the sequence of the technological process of construction of an underground tunnel, which is a guideline for subsequent projects.

Determination of dynamic loads in the crane lifting mechanism

Loading and unloading is an integral part of the technological process of construction. To perform these works mostly use cranes of different types.
 To ensure trouble-free operation and increase the reliability of cranes in the calculation of structures and components of their work equipment, it is important to take into account dynamic loads, which are several times higher than static loads.
 Elements of dynamic loads of the crane lifting mechanism are its elastic components - ropes and shafts, which are deformed under the action of loads. The magnitude of this deformation of the elements are taken into account by the coefficients of elasticity or flexibility of linear and torsional or their inverse value - the coefficients of rigidity. These coefficients depend on the linear or angular deformations, respectively.
 Due to the fact that the mechanism of lifting a load consists of a large number of elastic elements, the addition and solution of equations to determine these coefficients becomes a difficult task. In order to simplify the equations and these calculations, the paper recommends the above scheme of calculations according to which the rest of all elements of the mechanism are reduced to its first element (engine). This greatly simplifies the equations to be solved and determines the values ​​of the coefficients of elasticity or stiffness of the elements of the dynamic loads of the mechanism of lifting the load of cranes.
 According to a similar scheme is also determined by the moments of inertia of the mechanism of lifting the load during periods of acceleration and deceleration, the components of the values ​​that affect them. The equations for determining the terms of transients of the lifting mechanism (duration of acceleration and braking) are derived.
 The method of determining the coefficients of elasticity and stiffness of the elements of dynamic loads, moments of inertia, duration of acceleration and deceleration of the lifting mechanism can greatly simplify the solution of complex equations and determine their values ​​with sufficient accuracy.

SYSTEMATIZATION OF BIOGAS PROTECTION WORKS INCLUDED IN THE TECHNOLOGICAL PROCESS OF BUILDING CONSTRUCTION ON GAS-GENERATING SOILS

The article is devoted to solving the problem of the lack of a clear list of works on biogas protection of buildings built on gas-generating soils in normative documents. The aim of the research is the selection, analysis and systematization of work on biogas protection, taking into account the degree of gas saturation of soils, to include them in the technological process of construction of buildings. To achieve the goal, the method of research was chosen – the method of expert evaluation. To perform the study, all possible work on biogas protection is summarized in a common list, which the experts involved ranked, taking into account, among other things, the degree of gas saturation of soils on which the construction and the regulatory requirements for them. Divided and grouped into categories of gas-generating soils by the method of expert evaluation, the most important groups of works for the relevant category. The result of the research is systematized into groups a set of works on biogas protection of buildings, with the allocation of groups, priority for use in the technological process of construction of buildings for each category and combination of gas-generating soils.

PRINCIPLES OF BUILDING AN INFORMATION MODEL OF A SEPARATE CONSTRUCTION PROCESS

The world practice of construction processes information modeling is considered. The principles of constructing an information model of a separate construction process, isolated from the system of a calendar or network schedule for the creation of construction products, are proposed. The features of technological processes of construction and installation works are highlighted depending on the level of mechanization. The classification of technological processes according to the criterion “degree of mechanization” is given. The necessity of using the work front as the main element of the information model of a separate construction process is proved. The structure of the information model of a separate construction process has been developed, which is: a source of initial data, a computing device and a description of the result. The boundaries of the application of the separate construction process information model are defined. The prospects of scientific research and the features of information modeling applied to individual construction processes are shown.

Stages of Intellectualization of Engineering and Technical Support of Railway Construction

The article is devoted to the theoretical foundations of improving the engineering and technical support of railway construction. In the course of the study, it was determined that a number of stages of the development and implementation of technological processes contain tasks for which the use of automated design and control systems is sufficient. However, there are tasks whose solution depends on the experience and intuitive abilities of the engineer. In this case, it becomes possible to use some methods and means of artificial intelligence to solve technological, organizational and managerial tasks. In this regard, it is proposed to supplement the existing system of engineering and technical support for railway construction with a subsystem of engineering and intellectual support for the technological process of construction of a railway track object.

SCHEDULING WORK UNDER INTEGRATED URBAN DEVELOPMENT USING THE METHOD OF UNCERTAIN RESOURCE COEFFICIENTS

Introduction: Planning integrated development of a residential area involves determining the composition of the objects to be built and creating an appropriate integration mechanism, backed up by a generalized work schedule. The existing methods of forming integrated work schedules do not use a systemic approach, based on a universal mathematical model, to describe the organizational and technological aspects of construction. Methods: The present study uses the method of uncertain resource coefficients to demonstrate a mechanism for systemically describing organizational and technological construction processes. We present a way of adapting this method to forming a generalized construction schedule during integrated development. The proposed adaptation mechanism is based on managing schedule calculations by rationally influencing the elements of the linear equation system that describes the organizational and technological processes. Results and Discussion: The solutions presented in the paper are fully consistent with the calculations obtained by different flow methods of organizing construction, as well as with the critical path method used in project management programs. The method described in the paper has been implemented in well-known project management software, Microsoft Project, as a macro program in the Visual Basic for Applications programming language, making it possible to form, calculate, and optimize a schedule for integrated territory development using the unified software toolkit.

Innovative Tools for Improvement of Construction Organization Processes in the Conditions of Dense Urban Development

Purpose. The article is aimed to create scientific tools based on the analysis of modern innovative approaches and tools to improve the processes of construction organization in the conditions of dense urban development using logistics, which has modern concepts of improving the corresponding processes. Methodology. A systematic analysis of scientific works in terms of problems of organization of construction processes taking into account the conditions of dense development, which serves as a platform for the introduction of innovative tools based on the field of logistics knowledge. Findings. The expediency of using logistical approaches and concepts is substantiated, taking into account external factors and limitations that are caused by the environment and configuration of the site, causing difficulties for the internal organization of construction. Logistics tools (approach) allow more efficient use of scientific and practical potential in the further development of methods for improving organizational and technological solutions of construction production under conditions of the functional and planning infrastructure of cities. Principles of logistics will allow to balance construction production in the conditions of dense building; to use flexible tools as an opportunity to make changes in the schedule of material purchase, changes in terms of delivery of building materials, designs, details; minimize stocks of building materials. Originality. Based on scientific research, a model of optimization of organizational construction processes is presented, taking into account the conditions of dense urban development and functional and planning infrastructure of cities. A qualitatively new specialized scientific and practical sub-branch of knowledge, construction logistics, was created for complex conditions of urban development to perform organizational and technological processes of new construction. Practical value. The use of logistics approaches will improve and optimize the processes of construction organization, taking into account the essential factors of functional and planning infrastructure of the city, in which it is necessary to make rational management decisions. Flexibility, alternativeness of production and economic situations and transport networks during the complex organizational and technological processes of construction make it possible to reduce the cost of construction and installation works and help reduce the duration of construction.

Organization of Training in Construction Technological Processes Based On Digital Resources

The purpose of research is to show the efficiency of the virtual construction site of a large-panel residential building as a digital resource of training on technological processes of construction. As the research methodology appeared the digital paradigm, providing the application of digital resources into construction education, the correlation between the best practice and quality changes based on smart technologies. The principal results of the research are maintenance of the virtual construction site of the residential building; criteria for efficiency of training construction operation processes on the basis of a virtual construction site; levels of student readiness for smart technology applications. The significance of the results is that the content of the virtual construction site allows to develop skills of planning and management of virtual projects The criteria reflect the need of the digital economy for construction engineers who master modern digital technologies. The levels of students’ readiness to apply smart technologies reflect the current situation in construction education.

Institutional environment as a precondition for improving the technological progress of construction

The legislation of Ukraine on the regulation of urban planning activities establishes the legal and organizational foundations of urban planning activities, which are aimed at ensuring sustainable development of territories, taking into account State, public and private interests. In accordance with the legislative acts, a number of government decrees, orders of the Ministry of Development of Communities and Territories of Ukraine (formerly - the Ministry of Regional Development of Ukraine), state building codes (new or amended from among the current ones) have been developed. There is an urgent need to analyze the situation and further improve the legal regulation of construction, including permitting and approval procedures for the organization and management of construction in accordance with legislation and regulations, adaptation of regulatory policy to European standards as a prerequisite for improving organizational and technological processes of construction and determining their effectiveness.Based on this goal, the following set of issues is consistently considered: contractual relations in capital construction; main participants in the construction - the customer and contractor, investor, developer, etc .; conditions for concluding a contract; terms of performance of works (construction of object); calendar schedule of works; contract price and estimated cost of construction; types of contracts and their characteristics; the rights of the customer and the contractor; contracts for design and research work; methods of economic evaluation of options for the organization of technological processes of construction.Currently, work is underway to improve the legislation on the organization of construction activities, namely: architectural and construction control and supervision, permitting procedures in construction, licensing, self-regulation in urban planning, electronic systems and BIM-technology, technical regulation in construction and more. In this regard, the current guidelines will be clarified with the release of new laws and regulations.

Analysis of Output Parameters of a Three-Stage Asymmetric Vibration Device

There is a long-felt need for a wider use of asymmetric vibration devices in technological processes of construction and road-building operations. The methodology of engineering and design of multi-stage asymmetric vibration devices is in the conceptual phase and requires additional analytical studies, design studies and industrial tests. Asymmetric vibration devices may consist of two or more stages of unbalanced directional vibrators, speeds of rotation of the drive shafts whereof are divisible. This article considers the effect of the interrelation of static moments of unbalance of a three-stage asymmetric vibration device on the system’s dynamic amplification factor. The article describes a method to determine the rational interrelation of static moments of unbalance using a three-stage asymmetric vibration device as an example. The article will be interesting to specialists in the sphere of production of vibrating production machines and equipment.

Intellectualization of engineering and technical support of railway construction

The article is devoted to the theoretical foundations of improving the engineering support of railway construction. One of the main purposes of the existing engineering support system is to evaluate the results of development and monitor the implementation of technological processes for the construction of railway facilities. In the course of the study, it was determined that a number of stages in the development and implementation of technological processes contain tasks for which the use of automated design and control systems is sufficient. However, there are tasks whose solution depends on the experience and intuitive abilities of the engineer (developer of organizational and technological documentation). To solve such problems, in addition to settlement procedures, logical ones are also necessary. In addition, the intensification of railway construction, many restrictions on the production of works and resources, as well as deviations from planned indicators, require prompt decision-making aimed at compliance with design requirements. Obviously, the total amount of information and data on the design and actual technological processes does not guarantee the efficiency and rationality in decision-making by an engineer. In this case, to solve technological, organizational and managerial tasks, it becomes possible to use some methods and means of artificial intelligence. In this regard, it was proposed to supplement the existing system of engineering and technical support for railway construction with a subsystem of engineering and intellectual support for the technological process of constructing a railway track. For the purpose of intellectualization and the formation of a new paradigm of engineering support for railway construction, an analysis was made of modern and promising practices in the development and implementation of technological processes from the perspective of the life cycle of a railway track object. It was found that modern technological processes for the construction of railway facilities should be flexible to changing working conditions. The study showed that this can be achieved through the formation of adaptive digital technological regulations. The basis of the digital regulation is the information model of the technological process. The model formation procedure is divided into stages containing tasks, the solution of which is possible using artificial intelligence tools such as expert systems, artificial neural networks, and genetic algorithms. A fundamental feature of the engineering and intellectual support of the technological process is the possibility of its operational regulation based on the results of monitoring its development over time. A feature of this approach is the need for the operational processing of a large amount of data that determine the development of technological processes over time, the conditions of work, the production capabilities of construction (contracting) organizations. For this, the mathematical and conceptual models of an intelligent automated system have been developed. Its main purpose is the operational solution of the problems of development and implementation of the technological process of construction of railway facilities. The results obtained during the study, as well as the developed tools, made it possible to determine the possibilities of integrating the developed methodology into the existing system for designing and managing the construction of railway facilities. The results given in the article were obtained during the dissertation research performed by the author.

Improvement of organizational-technological decisions for restoration of engineering networks of existing industrial enterprises

Problem statement. Nowadays, most industrial enterprises need to be restored, which is associated not only with the period of their durability, but also with the improvement of production, increase of its technical and economic level and quality of products, improvement of operating conditions, quality of services, change of technical and economic indicators (quantity of products, power, functionality, geometric dimensions). Recovery is significantly different from new construction and has its own characteristics in the design, development of the technological process of construction, the specifics of the construction and installation works, which is associated with the constraint of the construction site, the need for phased implementation of work in different areas, a combination of the production activities of the enterprise with the construction and installation works, dismantling in some cases of old utility networks or parts thereof. The organization of work to restore engineering networks at existing enterprises depends on many factors that need to be linked together to optimize the preparation and conduct of work. When organizing the reconstruction of industrial enterprises, it is necessary to solve the problem of combining the activities of the enterprise in manufacturing products with the reconstruction of one of the types of communications (full, partial, without combination). The purpose of the article is to increase the efficiency of restoration of engineering networks of existing enterprises by optimizing organizational and technological solutions. Conclusions. The improvement of organizational and technological solutions, the restoration of enginering networks of existing industrial enterprises, is aimed at choosing an option in which, taking into account local conditions, the maximum reduction in the time required to complete the work is achieved with the efficient use of material and technical resources. An analysis of the features of the restoration of engineering networks of existing industrial enterprises has shown that one of the primary tasks of designing a rational technology and organizing the production of construction and installation works is the choice of a method for their implementation. Under the choice of the method of production of work is meant the development and consideration of its various options, as well as the selection and justification of the most rational (optimal) of them for given specific production conditions.

Quality Management of Building Materials and Building Productions Based on the Using of Real Estimates of Measurement Accuracy

The most important direction of quality improvement in construction is to increase the accuracy of measurements of parameters of building products and construction products, as well as the parameters of the technological process of construction and of production of building materials. Currently used standard estimates of measurement accuracy provide guaranteed but underestimated accuracy estimates. Although in fact, with the correct measurement methods and the use of a posteriori information, it is possible to build more realistic estimates of accuracy. The accuracy of such estimates is several times higher than the accuracy of standard estimates. The article investigated the problem of increasing the accuracy of measurements through the use of a posteriori information. An example of the application of the Bayesian approach in the conditions of the possibility of obtaining additional information and its use in order to build effective estimates of measurement accuracy is presented. It is assumed that the measurement result is the sum of the actual value of the parameter being measured and the measurement error. For the case of a uniform distribution of the real value of the measured parameter and measurement error, explicit analytical formulas were obtained for the differential distribution function of the measurement result and the conditional distribution of the real value for a known measurement result. These analytical dependencies, obtained as a result of integrating fractional rational expressions, are composite functions, which in different parts of the argument are specified using different analytical formulas. The analysis of the obtained analytical dependencies. Using numerical integration, we plotted the dependence of the square of the standard deviation of the real value of the measured parameter on the observed value of the random variable. It is shown that in the case when the standard deviation of the measuring device is less than three times or more than the standard deviation of the actual value of the parameter, the use of a posteriori information allows us to construct more realistic estimates of accuracy. The accuracy of the measurements can be obtained several times higher. It is noted that in the case of normal and exponential distribution of the real value and measurement error, the use of a posteriori information does not lead to an increase in measurement accuracy. The results obtained can be applied in the development of measurement methods, in the development of methods for verification and calibration of measurement instruments.

Requirements for Pavement Base Layers with Unbound Granular Material

Abstract Pavement structures, layers, and parameters must meet the strict requirements of applicable standards and regulations. The thickness of layers and the choice of materials depend on the factors involved, i.e., the traffic load and climatic factors (changes in temperature, water, rain, snow); they are also dependent on the geological environment at the road construction site and the parameters and properties of the embankment (the subgrade of the pavement). In some cases, the capacity of the existing transport infrastructure is on the edge of sustainability. The increase in the traffic load and the use of lower-class roads by freight transport, together with insufficient maintenance, has resulted in a deterioration of road conditions, thereby causing many deficiencies and failures. The required serviceability and operational performance of roads can be ensured by the choice of suitable quality materials and technological construction processes. Technologies that are environmentally acceptable and economically efficient should be preferred.

Designing optimal structure of road construction machines kits

The article presents modernized mathematical model for optimizing the structure of road sets of machines, taking into account the technical and organizational downtimes of mechanization facilities employed in technological construction processes. In the process of operation, technical downtimes are caused by the wear of parts, assemblies and units of transport and technological machines, the removal of which takes more time each year. This circumstance causes an adequate decrease in the annual output of the mechanization facilities. The organizational kind of downtimes is caused by internal and external factors. The internal factors lead to the under-exploitation of the potential capabilities of individual pieces of the equipment of the kit. External factors are characterized by late supply of construction materials, caused by the irregularity of their production and delivery. Dependencies between productivity and the operating period of transport-technological machines, obtained using this mathematical model, will allow determining the real time of work, the output of machines, taking into account their age.