bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis and optimization of the bearing capacity of connecting wooden structures with application of dowel type self-drilling
Authors: Phong Tran Quoc 
Published: August 2020

Abstract
The multiple shear connection with slotted-in steel plates and dowel-type self-drilling is a very efficient timber connections for frame and truss. It is used in practice, due to its high capacity and faster construction method. However, when the complex connection and many parameters affect the bearing capacity, instead of a ductile mechanism, brittle failure may govern its capacity. To achieve the desired working connection, the relationship between the connection configuration parameters is established but no standard specifically with this kind of connection. A series of parameters changes affecting the bearing capacity of the connection are given. Calculate and compare with many previous research methods in ductile failure modes to assess their prediction accuracy and optimal connection. A model for the optimization of the ductile failure mode for the multiple shear connections with slotted-in steel plates and dowel-type self-drilling is then proposed.
Constructive device for sediment flushing from water acceptance structure
Authors: Aynakulov Sh A , Karimova Kh , Shakirov B , Alibekov S , Mamajonov M 
Published: August 2020

Abstract
The article discusses a constructive solution for sediment flushing from the water acceptance chamber of the pumping station, which is solved by using a guide wall raised above the bottom of the chamber. The wall is installed at a distance L0 = (2.6 … 3)Di from the inlet of the suction pipe of the pump at an angle of 25.30° relative to the bottom of the chamber. Due to the installation of an inclined guide wall, the level difference is Δh = (0.08 … 0.1)Di, where Di is the diameter of the inlet of the suction pipe. To reduce the difference in water levels Δh = 9 … 11 cm from the action of the guide wall, through holes of rectangular cross-section are made in it with a width of Di and a height of 0.2Di. If the drag coefficient ξ for a chamber with sediment is ξ = 0.61, when washing off sediment it is equal to ξ = 0.491, so the pump flow from 424 l / s increased to 476 l / s, i.e. increased by 52 l / s. A comparative analysis of flushing sediment from the water acceptance chamber under laboratory conditions is compared with the results of the analysis under field conditions. According to the developed design, the pump efficiency increased by 5.9%, and the flow rate increased by 12.2%.
Development a mathematical model of a water-salt balance on irrigated lands of the Sirdarya area
Authors: Ergasheva D , Kasimbetova S , Aynakulov Sh , Sharipov D , Khamraeva Sh 
Published: August 2020

Abstract
The article presents the results of field studies and analysis of the parameters of the input and expenditure components of the water-salt balance, which makes it possible to assess the reclamation state of irrigated lands. Directly in the field, using the measurement determined the values of the input and expendable components of the water and salt balance, a tendency to improve or worsen the reclamation state of the irrigated lands of the Shuruzak massif and the Saykhunabad district of the Syrdarya region. The general water balance, the balance in the aeration zone and groundwater was compiled. Determination of water and salt balance in the aeration zone of soil and groundwater leads to the creation of optimal water-air and nutrient regimes for the development of crops and high yields. To determine the water and salt balance on the irrigated lands of the Saykhunabad region, a mathematical model was developed for the first time, based on which it is possible to predict changes in the water, salt regimes and the regime of groundwater in the irrigated massif. Their regulation is very important for determining practical measures to manage this regime in order to save irrigation water and improve the reclamation state of irrigated lands.
Optimal order of construction of facilities in complex development with minimal additional costs
Authors: Mailyan Alexander , Korol Elena , Petrosyan Rima , Antoniadi Diana 
Published: August 2020

Abstract
Stream methods of work during the construction of a group of construction projects provide the selection of priorities in the optimization of calendar plans. This can be a reduction in the duration of construction or resource provision in time. Due to the change in the arrangement of objects in the stream, the total duration of the work on the entire object complex can be changed. By the methods of organizational and technological modeling, a rational sequence of work is selected taking into account the optimization of resource costs. When constructing a complex of objects, a comparative analysis of various combinations of grouping objects, using the methods of decomposition and aggregation, allows you to carry out a numerical rating of various parameters of the work, such as duration, labor, providing material and technical resources, etc. This ensures the optimal ratio between the duration of the construction of the object complex and additional costs that arise during the parallel construction of several objects. A graphical interpretation of the choice of the optimal organizational and technological solution is work schedules at the facilities, allowing differentially and integrally to evaluate the development of material and technical resources.
Sound insulation of PVC windows at negative outdoor temperatures
Authors: Konstantinov A , Verkhovsky A , Lyabakova E 
Published: August 2020

Abstract
The PVC windows using experience in the climatic conditions of the Russian Federation shows that their profile elements are subject to temperature deformations under the influence of the temperature gradient of outdoor air and indoor air. This physical phenomenon is observed both in the summer and winter operation period. In this article we study the influence of external air negative temperatures into the sound insulation of PVC windows. The research was performed on a standard PVC window in a climate chamber with acoustic equipment. The PVC window sound insulation measurements were carried out at the following temperatures inside the cold compartment of the climate chamber+20 °C, 0°C, -5°C, -20°C (at a constant temperature in the warm compartment of the chamber + 20°C). It is established that the reduction of PVC windows sound insulation begins to occur only at outdoor temperatures below 0 °C. The sound insulation of PVC window at an outdoor temperature -20°C is 3 dB lower than the sound insulation of the same window, determined under standard conditions (+20 °C). Obviously, existing methods of calculation of sound insulation of PVC windows it is necessary to adjust in terms of operational ambient temperatures and design features of the windows.
Strength of wood reinforced with a polymer composite for crumpling across the fibers
Authors: Lisyatnikov M S , Glebova T O , Ageev S P , Ivaniuk A M 
Published: August 2020

Abstract
A method for strengthening beams on a support with a polymer composite based on fiberglass and an epoxy matrix with the inclusion of carbon nanotubes in its composition is proposed. To prove the effectiveness of reinforcement and determine quantitative and qualitative characteristics, experimental studies were conducted on standard wooden samples with and without reinforcement. Before conducting the experiment, it was planned in order to achieve maximum measurement accuracy with a minimum number of experiments and maintain the statistical reliability of the results. As a result of planning, a multi-factor formula was obtained for determining the strength of the sample depending on any combination of three variable factors: the reinforcement coefficient, the quantitative component of carbon nanotubes, and the curing temperature of the composite. The tests were performed under normal conditions. As a result of compression tests across the fibers of experimental samples, it was found that the strength limit of reinforced samples in comparison with wooden ones without reinforcement increases to 39 %, and the destruction is plastic.
Foam fiber-reinforced concrete: technology and methodology of selection of the composition
Authors: Zhukov Aleksey D , Bessonov Igor , Efimov Boris , Medvedev Andrey , Poserenin Alexey 
Published: August 2020

Abstract
Disperse reinforcement of the mineral matrix in concrete technology makes it possible to manufacture structures of complex configuration, to solve problems of frost-resistance of products, minimize shrinkage deformations. The technologies of application of dispersed reinforcement of a concrete matrix with the help of synthetic, mineral and metal fibers has been developed. Perspective is considered reinforcement with basalt fiber - material resistant in alkaline environments of cement stone and having high adhesion to the mineral matrix. Foam concrete in industrial conditions is produced either in a one-stage or two-stage scheme. The technology of foam concrete of two-stage manufacturing has been studied quite well and its formulations have passed a wide approbation. The novelty of the research is the integration of basalt fibers into the concrete mix as a dispersive reinforcing component. This aspect has been given special attention in research. It is established that the consumption of basalt fiber affects both strength and density of cellular concrete products. The length of basalt fiber affects only the strength of products. As a result of the system analysis of penofibrobeton technology using the methodology of mathematical planning of a multifactorial experiment, obtaining results based on statistical analysis and optimizing these results, a mathematical model has been built and a technique has been developed of selecting of the composition penofibrobeton in densities from 400 to 600 kg/m3.
Qualitative risk approach in the construction of electric power facilities
Authors: Borkovskaya Victoria G , Skrynnik Anton 
Published: August 2020

Abstract
The main issue of the study is the problem of risk management in the planning and implementation of projects for the construction of electric power facilities. Projects for the construction of such facilities, which are characterized by high technological complexity and uniqueness, at the stages of design, equipment delivery, construction and commissioning, face unforeseen circumstances and, often, the project management is not ready to solve the problems that have arisen. The purpose of this article is to describe a methodology for qualitative risk assessments in relation to projects for the construction of electric power facilities with the determination of levels of responsibility, analysis of stakeholders, and distribution of risks among stakeholders. The proposed method can be used for risk analysis and making informed decisions at the stages of planning and implementing projects for the construction of electric power facilities.
Composite materials based on non-recyclable polyethylene
Authors: Saporovskaya T Y , Prohorov S V , Timakov E A 
Published: August 2020

Abstract
In this paper, the possibilities of creating composite materials based on cross-linked polyethylene (XPE) were investigated. The environmental benefit of recycling such polyethylene is to free up space for buildings that are now occupied by landfills. The influence of polyethylene, previously considered non-recyclable, on the strength characteristics of concrete is shown. In the course of the work, waste from the existing chemical industry was used, with varying particle sizes (0.5-15 mm). The analysis of patent information on the utilization of polyethylene in construction materials. Using mathematical planning methods, the compositions of composite materials are optimized. The volume of solid waste of non-recyclable plastic is more than 1.3 billion tons. Its decay period in the natural environment is more than 400 years. There is no world experience in the use of such waste, so the problem of its disposal is more than relevant. Thanks to the results obtained, it is possible to significantly reduce the degree of environmental pollution by waste of chemically cross-linked polyethylene, and get a new composite material for construction, a wide range of applications. The economic justification of the developed technology being introduced into mass production is presented.
Rayleigh surface waves in assessing the state of metal structures
Authors: Erofeev V I , Rodyushkin V M , Ilyakhinsky A V , Nikitina E A , Khazov P A 
Published: August 2020

Abstract
The work is devoted to the search of a method of ultrasonic sounding for identification of the material state, permitting to refer the diagnosed structure to the class of structures, whose state is connected with the appearance of plastic deformations. The study has shown the application of surface Rayleigh waves allows to estimate the stress-strain state of metal structures in the field of both elastic and plastic deformation.
Characteristics of heat insulating foam aluminum silicate under change of heat treatment parameters
Authors: Khristoforova I A , Khristoforov A I , Timakov E A 
Published: August 2020

Abstract
In case of heat insulation, work material choice depends on the type of protected object, materials available and usage convenience. Durability match between heat insulation and basic building material lies at the core of insulation choice. Foam glass and its derivatives (e.g. foam aluminum silicate) have properties meeting the strictest requirements of today. These rigid highly porous foam insulation materials have closed cell structure, representing solidified glass foam with either polyhedral or rounded cells. For these reasons, usage of highly efficient environmentally friendly foam insulation materials is so relevant today. A process was developed for batch heat treatment using local natural raw materials found in Vladimir region. The process consists of components joint grinding, produced batch preparation, blank pressing, foaming and heat annealing, and property research for produced materials. It turns out that foaming parameters are strongly intervened with batch composition, therefore requiring constant adjustment for each batch composition change. Researches show that specific heat treatment parameters provide foam formation with high foaming ratio and closed pore structure. Furthermore, we managed to create a foam aluminum silicate having the following features: density 130-350 kg/m3, coefficient of thermal conductivity 0.07 – 0.11 W/m·K, compressive strength 0.7 – 3.0 MPa.
Wall materials based on complex binders and organic aggregate
Authors: Zakrevskaya L V , Gavrilenko Andrei , Andreeva Ksenia , Lubin Petr , Kapush Ilya , Udin Igor 
Published: August 2020

Abstract
The technology of hards concrete developed in this study differs primarily by the binders - semi-burnt dolomite, related to magnesia cements. Grouting fluid is bischofite (MgCl2) or magnesium sulfate (MgSO4), density 1.2 g/cm3. One of the ways of strengthening and adding new properties to hards concrete, which can significantly expand its application domain, is an introduction of chrysotile to the concrete composition. The best specimen have density 570-585 kg/m3, strength 14.5 - 15.1 MPa and low thermal conductivity (0.065-0.074) W/(m·K), what allow them to serve as structural and thermal insulation material. Sound absorption coefficient is from 0.17 to 0.6 (at audio frequencies of 125-2000 Hz). Frost resistance exceeds 50 cycles, water absorption is 40-50%, shrinkage is less than 0.4%, fire stability is 0.75-1.54. Based on the results obtained, it can be concluded that the material is most applicable in low-rise construction. The developed material will solve the problem of utilizing of industrial hemp waste from textile production and dolomite waste in the form of a magnesian binder, thereby reducing the cost of the material in compare with existing world analogues.
The two-factor destructions model of the composite
Authors: Varlamov A , Shafranovskaya T , Rimshin V , Kurbatov V 
Published: August 2020

Abstract
The article examines the destruction of a composite using a diamond disk. The composite structure is adopted as a two-factor symmetric model, in which the composite grains are represented as balls in the matrix body. A feature of the design is the symmetry of the crack along the two main planes. A model of interaction of a diamond disk with a composite is developed. The destruction of composite models was carried out by cutting the individual bands. Cutting revealed the cyclical nature of the energy characteristics of the fracture models. The cyclic nature is described by a sinusoidal wave of structure destruction. The simulation results provide a formula for the composite structure, which is described using the energy characteristics of cutting. The structure and parameters of the fracture model obtained during cutting allowed us to fully describe the composite structure model. The results of modeling show that it is possible to fully describe the model of a concrete composite using only the energy parameters obtained during cutting of the material.
Principles of creating new alloy compositions for the production of cast protectors
Authors: Kechin V A , Kireev A V , Lyublinski E Y 
Published: August 2020

Abstract
Aluminum protectors are used in cathodic systems for protecting metal structures from electrochemical corrosion. The materials of the article are devoted to the selection of elements for alloying aluminum, based on the analysis of physicochemical, technological and electrochemical characteristics of the alloy base and elements of the periodic system named after D.I. Mendeleev. Zn, Mg, Mn, Ti and Zr were selected as the main alloying components by the tendency of elements to alloy formation and to obtain a homogeneous structure, taking into account their effect on the anodic activity and resistivity of oxides on the metal surface. The obtained research results are in good agreement with the well-known international standards for the chemical compositions of aluminum tread alloys, for which magnesium, zinc, and manganese are present as the main alloying components. For experimental studies, Mg, Zn, Mn were chosen as alloying additives, and Si, Fe as impurities. The optimal the concentration range of the aluminum alloy will be as follows: for zinc, 3.6-5.4; for magnesium, 0.55-1.05; for manganese 0-0.3. The content of Si and Fe in the alloy is limited to 0.06 and 0.01%, respectively. The maximum value of the CUE - 75.78%.
Low heat concrete with ground granulated blast furnace slag
Authors: Barabanshchikov Yu , Usanova K , Akimov S , Bílý P 
Published: August 2020

AbstractThe subject of the research is a concrete with partial replacement of cement with an increased amount of ground granulated blast furnace slag to reduce heat release of concrete for the structures of the Akkuyu Nuclear Power Plant (Iskenderun, Turkey). The concrete was tested for heat release, compressive strength and shrinkage. Several mixes with partial replacement of cement by the slag from «Iskenderun Demir ve Çelik A.Ş.» were used for testing. The heat release is reduced by up to 50 % and the loss of strength is not more than 36 %. This is the result of an increase in the slag content in the mixed binder (cement + slag) and a decrease in the cement content. The optimal slag content in the mixed binder is 25 %. There is an increase in concrete strength by 3-4 % and a decrease in heat release by 13 % compared to the cement binder. All tested concrete mixtures with the cement replacement by the slag have a decrease of the heat release, which is greater than a decrease in the concrete strength. The cement replacement by the slag leads to an increase in autogenous shrinkage. If the binder contains 50 % of the slag, the highest value of the autogenic shrinkage is observed. This value is approximately twice greater than the shrinkage of concrete with the cement binder. If the binder contains 75 % of the slag, the shrinkage is less. The replacement of the cement content by the slag is recommended to reduce the heat release of concrete, in order to increase its thermal crack resistance.
Evaluation of quality parameters of the torque transmission connections of the multi-purpose machine spindle joints
Authors: Il’inykh Viktor , Pichuev Egor 
Published: August 2020

Abstract
The article presents the results of theoretical studies of a multi-purpose machine when assembling an HSK spindle-mandrel connection for accuracy, contact stiffness and strength. Studies were based on the developed original mathematical program complex for assessing the quality parameters of machine connections. They have been carried out with respect to HSK spindle-mandrel connections under conditions of multiple tool changes. Simulation of the coupling of connection parts for different values of the fastening (assembly) forces showed that HSK-type connections have a static uncertainty of basing under external loading conditions. Analysis of the stress-strain state of the connection joints was based on the finite element method when using software in the FEMAP 11.1 with NX NASTRAN. It showed that an unorganized change of bases occurs under the influence of external conditional load. It has been established that for tool mandrels of the HSK-63 type with a fixing force of 900 to 23000 N, the elastic displacements at the end of the mandrel vary from 1.5 to 0.6 μm under the condition of an external conditional load of 1732 N and, accordingly, from 8.0 to 2.5 μm with an external load of 6070 N. It was established that with a limiting value of the mandrel clamping force equal to 23000 N under conditions of external loading an unorganized change of bases occurs, namely: the end faces of the contact of the tool mandrel and the spindle are pressed, which reduces the geometric accuracy of a multi-purpose machine with a CNC.
Thermal insulation materials based on polyurethane foam modified by the polymethylphenylsiloxane
Authors: Smirnov K V , Chuklanov V Yu , Smirnova N N 
Published: August 2020

Abstract
In this work, the modification process of thermal insulation materials based on polyurethane foam by the organosilicon polymer polymethylphenylsiloxane was studied. The current state of thermal insulation materials based on polyurethanes problem and ways to improve the thermal and operational properties of foamed polyurethanes, such as maintaining the stability of characteristics under the influence of adverse factors, reducing moisture absorption and water absorption, were also analyzed. The influence of polymethylphenylsiloxane on the morphological characteristics and density of the resulting foams was studied. It was found that the introduced modifier affects the density of the resulting foam materials slightly. In this case, the introduction of an organosilicon product regardless of the ratio of the initial components leads to a decrease in water absorption. Studies have shown that the introduction of an organosilicon modifier in an amount of 2.5-5 m. h. leads to an increase in the heat resistance of the material. The heat resistance of modified samples increased by an average of 30-40 °C. Thus, the conducted research showed a real possibility of using the developed modified polyurethane foams for thermal insulation of industrial and civil objects.