This article discusses the system of construction control of capital construction objects, its participants and their interaction. Purpose: analysis of the building control system, interaction of its participants, determination of the main factors influencing the functioning of the building control system. Methods: the method of synthesis and scientific analysis was used. Results: the authors identified the main factors influencing the efficiency of the construction control system. Conclusions: the identified main factors provoke a decrease in the efficiency of the construction control system. The prospect of the study is further analysis of the factors to find their elimination.
Keywords: construction control system, interaction of participants, factors
An approach is proposed to determine the parameters of concreting flat massive foundation slabs - the operational performance of the concrete mix supplier, vehicles and concrete pump, taking into account the limiting factors - the intensity of the supply and placement of the concrete mix and the time of overlapping layers. A scheme for determining the overall coefficient of operational performance is proposed. As a result of timing, the values of the transition coefficient from technical to operational productivity, respectively, for a concrete mixer truck with a volume of 10 m3 from 0.54 to 0.65 and 0.41 for a concrete pump truck with a technical productivity of 120 m3 / h, respectively, were determined when concreting a massive flat foundation slab with a volume of 1500 m3 using concrete mix with grade P4 for workability at a delivery distance of up to 50 m. It is proposed to consider a coefficient that takes into account the decrease in the productivity of an autoconcrete pump due to the variability of the concrete mix supply mode as the main reserve for increasing operational productivity. Schemes are given for determining the duration of concreting a structure without technological interruptions, both with an equal thickness of the stacked layers, and with different schemes for assigning the thicknesses of the stacked layers. The inexpediency of erecting such structures with a layer overlapping time of less than 4 hours is shown. The approach considered in the work can be used to select rational methods for concreting such structures in a continuous pattern or with division into temperature-shrinkage blocks and the construction of working joints. The latter scheme, in connection with the problem of ensuring the quality of the seams and the solidity of the structure, seems to be less preferable.
Keywords: concreting intensity, technical productivity, operational productivity, massive flat foundation slabs, layer overlap time, layer thickness
The article describes the conduct of field studies carried out during the overhaul of the cultural heritage object – the building of MBOU "Gymnasium No. 45" to establish rational parameters of injection of cement-sand mortar, the choice of the type and design of injectors and the scheme of drilling injection wells. It is proved that the technical solutions adopted in the soil fixing project are not optimal and do not provide the required quality of work. Recommendations on technological and constructive solutions for fixing soils have been developed and implemented in practice, taking into account engineering and geological conditions, the results of the survey and fixing at the pilot site.
Keywords: subsidence soil, foundation, cementation, injector, well drilling, geocomposite
Complex flows (CFC, CFA, СFP) are calculated using the critical method. A comparative analysis of the methods of complex flows was made, which showed that the CFC and CFP have the shortest duration of the overhaul of the facades of three objects, which is 131 days. Based on a comparison of the options for calculating complex flows by different methods, we can conclude that the CFP method is the most suitable, because the duration of the overhaul is the shortest. CFP is the traditional and most optimal method that ensures the minimum duration of the whole complex of works and is widely used at the present time.
Keywords: complex flows, calculating, methods, duration
The aim of this article is to highlight the role of Building Information Modeling in minimizing the energy consumption of a building. To achieve this, a project was selected in Iraq and the annual energy consumption in this project was determined. Through the analysis of the building using building information modeling, it was found that the addition of some alternatives during implementation effectively contributes to reducing energy consumption . For example, the use of foam Material above roofs reduces the Energy Use Intensity (EUI) to (1,135 MJ/m²/year), Electricity (294,591 kWh), and Fuel (117,587 MJ) , and using Sand Stone in Wall Finishing reduces the Energy Use Intensity (EUI) to (1,116 MJ/m²/year), Electricity (228,898 kWh), and Fuel (496,223 MJ). Through these results, it appears that new materials must be incorporated into the building, as they are of high quality in thermal insulation and reduce energy consumption. By adding the alternative materials above, and from the results that appeared, it was found that these materials reduced the energy consumption of the building by a good percentage and thus obtaining a higher quality of the building by improving its performance.
Keywords: energy analysis of buildings, construction project, Building Information Modeling, analyzing alternatives
This article analyzes two systems of logistics for construction organizations based on the concept of Material Requirements Planning (MRP) and Just-in-Time (JIT). The main advantages and disadvantages of each system were investigated, and which of them are most effective in the current conditions were determined. Possible options for improving MTO systems are considered, as well as recommendations for the introduction of MRP and JIT into the practice of construction organizations to increase efficiency and reduce costs are proposed. The article will be useful for specialists in the field of construction and logistics, as well as for everyone who works in the field of management and optimization of business processes.
Keywords: logistics, Material Requirements Planning concept, Just-in-Time concept, construction project planning
This article presents the results of a study of the process of decompaction of clay soils when they are used in soil structures. To study this issue, the following factors were chosen: the dimensions of the test samples, the amount of load on the samples, swelling when soils are moistened and shrinkage when they are dried, and the loss of strength of the samples during their decompaction was also estimated. All studies with soils were carried out in laboratory conditions. In the course of the research, dependences of relative decompaction on vertical load and changes in shear forces depending on the degree of moisture during decompaction of soils were obtained. The main conclusions of the work are given.
Keywords: clayey soil, decompaction of soils, mineralogical composition, optimal soil moisture content, density of the soil skeleton
The problem of ensuring trouble-free operation of field pipelines is becoming more and more urgent from year to year. The development of deposits in areas with difficult natural and climatic conditions (the Far North, Western Siberia) requires a new approach to improving the reliability of pipeline systems. Along with the search for new technologies in construction and operation, the use of modern composite materials in the production of pipes is a primary task. Analysis of the causes of failures of field pipelines in the permafrost zone allowed us to identify the main ones: corrosion, water hammer, loss of stability as a result of frost heaving of soils. Comparative calculations of steel and fiberglass pipelines allow us to recommend the latter as an alternative to metal pipelines, because they have better corrosion and abrasive resistance, low roughness and thermal conductivity, high ductility and manufacturability.
Keywords: field pipeline, fiberglass, analysis, reliability, permafrost, corrosion, water hammer, loss of stable position, frost heaving
The design of the organizational structure is an integral factor in the formation of any organization, including in the construction industry. The changing operating conditions of enterprises existing in the era of the information revolution directly affect the efficiency of organizations and the entire construction industry. The impact of the latest technologies should be reflected in the planning, organization and control at all stages of the life cycle of a construction object.
Keywords: construction, organization, management, planning, design, organizational structure, virtual structure, virtuality, digitalization, Gartner curve
The article contains statistics on the number of destroyed buildings as a result of emergencies that have occurred over the past twenty years. A table has been formed taking into account the factors of selection of the method of erecting buildings.
Keywords: earthquake, construction technology, factor, selection of construction method
Currently, due to the growing shortage of basic energy resources, the increase in the cost of their production and the presence of acute problems associated with environmental degradation, the integrated use of energy-saving measures and innovative energy-efficient technologies in the construction industry is one of the necessary conditions for the successful development of the country's national economy and maintaining a favorable environmental conditions.
Keywords: energy saving, resource saving, energy efficient technologies, construction industry, alternative energy sources
On the basis of the study, an analysis was made of the capacity of the roundabout according to the existing traffic intensity in the city, taking into account the composition of the traffic flow, the main factors affecting the passage of vehicles at the entrance to the self-regulated intersection are given. The possibilities of reducing congestion within the framework of the existing street and road network of the city are analyzed, conclusions and recommendations are given based on the results obtained.
Keywords: traffic capacity, traffic composition, roundabout, design speed, vehicle spacing, center island, load level, congestion, normalized traffic volume, number of lanes, service level
The relevance of forensic construction and technical expertise in the Russian Federation increases with the increase in the level of urbanization and at the same time the community of forensic construction experts with deep knowledge in the construction field obtained as a result of professional education is growing rapidly. The article raises the issues of lagging the level of preparedness of construction experts in procedural matters, in the skills of mastering the art of polemics, in the ability to flawlessly design the results of the examination in the form of an expert opinion. The authors of the article, based on the study of the practice of conducting judicial construction and technical examinations, analyzed the organizational and legal problems arising from the expert in connection with the violation of the principle of unity of form and content during the examination, underestimating the importance of putting evidence in a strict procedural form.
Keywords: construction and technical forensic examination, special knowledge, forensic expert, examination production, examination procedure
There are a lot of monolithic and precast-monolithic reinforced concrete structures in construction. The relevance of the issue of ensuring reliable contact of concrete in the seams and joints in the contact zone of newly laid (""new"") concrete with already gained a certain strength (""old"") concrete is increasing. In the work, the influence of the pH of the medium on the adhesion strength of ""new"" and ""old"" concrete, which occurs when making joints in prefabricated monolithic structures and organizing technological seams of concreting in monolithic construction, was considered. Standard methods were used. Experimental data have been obtained that indicate the influence of the pH of the ""new"" medium on the adhesion strength of the ""new"" concrete with the base of the ""old"" concrete. The analysis and comparison of the received results with the data of the researches conducted earlier is carried out. Recommendations are formulated to improve the strength of concrete contact in seams and joints during the construction of monolithic and precast-monolithic reinforced concrete structures.
Keywords: new-to-old concrete bonding, technological concreting joint, monolithic reinforced concrete structures, precast-monolithic reinforced concrete structures
The main problems of wear of the upper layer of asphalt concrete pavement during intensive use, from the wheels of the vehicle, the roadbed of public roads are considered. The task is to increase the strength characteristics of road pavements from hot mix asphalt, taking into account the use of lime-containing components in the composition of the mineral powder. To achieve this goal, the factors influencing the increase in the operational parameters of road surfaces are considered. The use of lime-containing components with high chemical activity is substantiated. The physical and chemical properties of lime form a structured layer of bitumen in the zone of contact with mineral substances, which is resistant to the aging process. There is an increase in strength and water resistance due to the high adsorption capacity and chemical activity of lime-containing components. During intermolecular interaction in the contact zones of calcium oxide grains with an organic binder, a coagulation-condensation structure is formed. Crystallization structures are shaped like crystals and evenly distributed in the mixture before the formation of the asphalt concrete pavement, which leads to increased strength and shear resistance. According to the results of experimental studies, the road surface is characterized by increased strength and water resistance. A conclusion was made about the effect of the use of lime in the composition of mineral powders on the performance properties of road surfaces.
Keywords: asphalt concrete coating, performance indicators, strength, water resistance, structure formation, lime, calcium oxide
When conducting quality control, it is necessary to consider the quality of both each individual element of the facade and the quality of the hinged facade as a system. When structuring the review of tools for instrumental quality control of curtain facade systems, their application should be considered according to controlled parameters, which can be divided into two groups. The quality control group of facade system elements combines methods and tools used in quality control of building materials and does not require the contractor to know about the principles of the hinged facade system. The quality control group of the device (assembly) of the hinged facade consists of operations to determine the quality of the operability of the hinged facade system. This group is entirely based on the idea of the work of the hinged facade as a single system. Based on the results of systematization and generalization of data, it was concluded that the current regulatory documentation regulates the use of instrumental control tools, leaving aside the issues of organization that come to the fore when quality control of the hinged facade of a construction object as a whole, when there is a task of choosing and using several tools of instrumental control at the same time. It is these questions that should be the subject of further research.
Keywords: systems of hinged facades, quality control organizations, a systematic approach in the organization, instrumental control, elements of the facade system, the device of the hinged facade, methods and means of control
The article presents experimental studies of the effect of activated mixing water on the technological properties of building cement mixtures prepared with water treated in the electric field of soluble electrodes. As a result of water treatment in the electric field of soluble electrodes, the material of the electrodes dissolves and, depending on the field parameters (intensity, current strength), the water is saturated with polyvalent aluminum hydroxide, which affects the formation of a crystallization structure, which is formed due to the chemical interaction of the binder and ions of the dissolved material electrodes. As a result of the formation of crystalline hydrates, the hardening process is accelerated and contributes to an increase in the technological properties of the building mixture (strength, normal density of the mixture, setting time). The purpose of the study: scientific substantiation of the effect of water treated in the electric field of soluble electrodes on improving the technological properties of the building mixture. Methods: experimental studies of the effect of mixing water treated in the electric field of soluble aluminum electrodes, depending on the material of the electrodes and the characteristics of the electric field, on the technological properties of the mixture. To determine the effect of increasing the technological characteristics of the building mixture, the influence of the duration and modes of water preparation on the strength of the cement stone at different hardening times, the setting time, and the plasticity of the mixture were studied. Results: The results of experimental studies proved the possibility of improving the technological properties of building mixtures prepared with water treated in the electric field of soluble electrodes, confirmed the possibility of increasing the compressive strength of the studied samples compared to control samples. A cement mixture prepared with treated water is more plastic than a mixture prepared with ordinary water.
Keywords: electric field, soluble electrodes, tension, cement stone, strength, mobility
The article discusses a methodology for improving the energy efficiency of historical buildings that have objects of protection. The main ways of energy saving, which are revealed at the level of the microclimate of the premises, are also considered. The relevance of the topic is due to the complexity of performing work to improve energy efficiency if it is necessary to preserve the historical value of cultural heritage sites. The article proposes organizational and technological measures that allow optimizing costs by reducing losses of thermal energy, by modernizing heating, ventilation and air conditioning systems in the conditions of the historical development of the city of St. Petersburg.
Keywords: energy efficiency, construction organization, engineering systems, restoration work, historical buildings
The article compares the technologies of methods of building construction in a short time, shows the advantages and disadvantages. A summary table of comparative characteristics of building construction technologies has been formed, the terms of construction of one floor for each method and the limitations of its application have been determined.
Keywords: method of lifting floors and floors, construction technology, monolithic, large-block, frame, volumetric-modular, contour, advantages, disadvantages
The article is devoted to solving the problems of choosing a variant of the calendar plan in the complex development of residential microdistricts. At present, a methodology for linking construction and installation works in time and space is being developed, new methods for calculating the organization of work are emerging. Due to the constant change in regulatory requirements in construction, the essential characteristics of scheduling methods change. Variant analysis may include a sufficiently large number of indicators of the quality of the organization of complex development. Therefore, a method for comparing options and choosing the best one is proposed, which takes into account an unlimited number of indicators of the quality of work organization. At the same time, different indicators can be taken into account for different regions, as well as new ones can be added. The effectiveness of the methodology is analyzed on the example of a residential area.
Keywords: residential area, variant analysis, flow organization of work, quality indicators, regulatory requirements
The purpose of this work is to develop a list of possible categories of the need for major repairs and appropriate criteria for evaluating structural elements and in-house engineering systems. In the process of working on this study, methods of statistical data collection and expert evaluation were applied. As a result of this study, a table of the Category of the need for major repairs of apartment buildings, Criteria for assessing the need for major repairs of apartment buildings, was also presented by the algorithm of actions of a specialist in determining the need for major repairs of apartment buildings. This work is an effective and relevant method for determining the need for major repairs of apartment buildings in comparison with VSN 53-86(p) "Rules for assessing the physical wear of residential buildings".
Keywords: major repairs, apartment building, expert evaluation method, operational reliability, category, criterion
The article aims to reveal the essence of the application of multi-criteria decision-making methods in relation to the process of organizing construction production. An overview of multi-criteria decision-making methods is presented. The criteria for the optimal choice of the calendar plan as the main document in the design and implementation of the construction process are described. Using the example of the initial construction schedule, alternative options are proposed and calculation is carried out using multi-criteria decision-making methods to select the best one based on the specified criteria and the situation
Keywords: multi-criteria decision-making methods, calendar plan, construction process, construction organization.
In the modern world, the issue of the importance of energy conservation and energy efficiency improvement in various areas, including the housing and communal sector, is quite acute. The use of modern energy-efficient materials and technologies in residential buildings, including during the overhaul of residential buildings, makes it possible to reduce energy consumption and save significant funds for citizens on utility bills.
Keywords: energy intensity, energy efficient technologies, energy saving, housing and communal services, overhaul
The authors of the article have developed an economic and mathematical model for determining the influence of factors characterizing the specifics of dismantling works on the operating costs and duration of operation of machines and mechanisms, the scientific novelty of which is that, unlike existing models, it takes into account the normative-parametric method, regression and covariance dependencies, which makes it possible to assess the totality of the influence of factors on operational costs and duration of operation of machines and mechanisms, describe the procedure for calculating the operating costs and duration of operation of machines and mechanisms and generate the amount of investment in the operating costs of machines and mechanisms.
Keywords: dismantling works, economic and mathematical model, operating costs, machines and mechanisms
This article described in detail the visualization of 5 case studies in Iraq with two important subjects; The first subject is construction quality control using BIM-compliant construction projects employing Autodesk Revit software; The second subject is quality assurance using BIM and energy analysis, which evaluates the energy usage in accordance with BIM utilizing Autodesk Revit software, and Autodesk Green Building Studio(GBS) Cloud. There are several causes that lead to the selection of these case studies. These case studies are applied models or examples executed by many Ministries such models exist in other governorates in Iraq. Despite the fact that the research topic of quality improvement utilizing Building Information Modeling (BIM) technology was not used in the chosen models, these buildings had several challenges throughout the execution phase. This research will be more valuable when implementing government agencies and private sector companies specialized in construction. wants to use BIM technology to improve the execution quality for future buildings.
Keywords: energy analysis of buildings, construction project, Building Information Modeling, quality, quality control, quality assurance