bluuebunny/crossref_metadata_2025_split huggingface dataset:
Insulation system of low-rise buildings on a wooden frame
Authors: Fedyukova Margarita , Kartashov Artem , Veremeev Daniil , Zhukov Alexey , Ushakov Andrey 
Published: July 2020

Abstract
Residential development of agricultural territories involves the use of low-cost construction solutions to provide housing for emerging new farms or implemented during the development of gardening plots. In this case, it is advisable to construct frame buildings with effective insulation systems.
The article presents the results of studies of the properties and application features for warming wooden structures of rolled foam polyethylene with or without a metallized coating. The tensile strength tests in the longitudinal direction were carried out in accordance with the standard. It was found that the tensile strength in the longitudinal direction for products with a metallized coating is 80–92 kPa, without a metallized coating – 80-87 kPa, and for a weld - 29-32 kPa.
As a result of the studies, insulation systems were developed (which have found wide practical application) and a full-scale thermophysical assessment of the thermal characteristics of these systems and the condition of the wooden frame in the building was carried out.
The results of experimental determinations of the resistance of the outer wall of a wooden frame with a warming sheet of foamed polyethylene amounted to: thermal resistance 2.96 m2 °C / W, heat transfer resistance 3.12 m2 °C / W. The specific humidity of the pine timber was 7.7–7.8% - at the level of equilibrium humidity values. No putrefactive manifestations of the wooden frame were found, which confirms the advisability of using these insulation systems for the construction of rural residential buildings.
Pelletized fly ash aggregates use for making eco-friendly concrete
Authors: Bach D T , Hoang V L , Nguyen N B 
Published: July 2020

Abstract
Today Vietnam is facing a seriously environmental challenge in handling fly ash and bottom ash from coal power plants with annual emissions of up to 15 million tons. Using the coal ashes to produce building materials is considered a main solution for this issue. Due to shortage of natural aggregates, using the ashes as aggregates in concretes achieves many benefits. This paper presents research results of pelletizing fly ash to produce an aggregate for concrete. The fly ash aggregates had strength of about 3.1 MPa, apparent specific gravity of 2.1 g/cm3, bulk dry specific gravity of about 1450 kg/m3 and water absorption nearby 22%. The concrete made from a combination of fly ash and bottom ash aggregates had the density of about 2000kg/m3 and the compressive strength of 17.5- 46.3 MPa at 28 days. Moreover, the aggregates were also applicable to manufacture ACOTEC wall panel with properties met requirements of TCVN 11524:2016.
Study of the phase composition of nanomodified biocidal cement stone by X-ray analysis
Authors: Grishina Anna 
Published: July 2020

Abstract
Due to high importance of cement concrete for construction industry it is essential to discover new ways towards increasing the durability of the concrete. The problem of low durability is of highest significance in case of hot and humid operating conditions. We have discovered that some biocidal modifiers are able to not only to solve their primary objective, but also may lead to higher resistance of concrete since they change the chemical composition of the cement stone. The results of the study of cement stone by X-ray phase analysis are presented in the article. It has been established that zinc hydrosilicates slow down the hydration of cement, and, thus, can successfully be used as agents which lead to increase of the concrete’s durability in hot climate.
Influence of drying temperature on compressive strength of geopolymer binder
Authors: Ngoc Lam Nguyen 
Published: July 2020

Abstract
Environmentally friendly materials with low CO2 emissions have become an inevitable trend of the construction industry. This requires research establishments to develop new construction material products and manufacturing enterprises to tale the chance and change production directions to meet the needs of the market. Among those new materials, Geopolymer materials promise to contribute to the development of increasingly sustainable construction. This paper aims to study the effect of drying temperature and drying time on compressive strength of geopolymer binders made from type F fly ash, ground granulated blast furnace slag combined with activators solution, including 10M NaOH caustic solution, liquid glass. Research results show that when the drying temperature increases from 60°C to 120°C and the drying time increases from 6 to 24 hours, the compressive strength of geopolymer binders could be enhanced from 2.5 to 3.0 times, compressive strength can reach over 50MPa, fully meet the requirements of the strength of binders used for manufacturing building materials products in civil engineering and industrial construction.
Radiation resistance evaluation of HCP with superplasticizers using DSC
Authors: Medvedev Vyacheslav 
Published: July 2020

Abstract
Today, when constructing new nuclear power plants, they most often start from the data of studies conducted more than 50 years ago. At the same time, the modern achievements of construction science, such as high-tech concrete compositions using highly effective admixtures, are applied either without preliminary studies with irradiation, or are not applied at all. In this paper, we consider the mechanism of radiation-thermal changes in concrete under the influence of neutron irradiation, as the most dangerous factor in the external impact on the design of modern nuclear power plants. The methodology for assessing the radiation resistance of concrete developed by domestic specialists, as well as the possibility of using the differential scanning calorimetry method as part of a comprehensive assessment of the effect of modern admixtures (using the example of superplasticizers) on the radiation resistance of concrete, is considered. It was proved that when analyzing the effect of admixtures on the radiation resistance of concrete, it is sufficient to conduct studies on the HCP rather than using concrete. To analytically establish the effect of superplasticizers on the radiation resistance of HCP, polycarboxylate superplasticizers of well-known brands with short side chains and insignificant steric effect, as well as long side chains and high steric effect. The general behaviour of HCP with superplasticizers was observed using DSC.
Assessment of the effect nitrites and fluorides on the change in the strength of concrete
Authors: Davidyuk Artem , Rybnov Dmitriy , Goglev Ilya , Truntov Pavel , Burkov Artem 
Published: July 2020

Abstract
The article describes examples of using inorganic salts and their mixtures for accelerate of hardening cement concretes in practice of modern construction. The results of the research of a complex mixed additive based on inorganic fluorides and nitrites, which accelerate the process of hardening of cement concrete are presented. The composition of the additive allows to accelerate the process of hardening the cement stone, due to the formation of dense and insoluble compounds in the pores of the cement stone. The experimental part included the process of determining the optimal amount of fluorides and nitrites in the additive. The results of the research showed a reduced additive consumption per 1m3 of heavy concrete. The advantages and disadvantages of the additive, which identified at experiments, allow us to recommend its use for accelerating the hardening of concrete in wet neutral and slightly acidic environments. The methods of tests that were carried out using certified and calibrated measuring instruments are described in detail. According to the results of the tests, the dependence of the concrete hardening rate on the amount of additive used was revealed, and the ways of practical use of the additive in the production technology of concrete and reinforced concrete were proposed. Also, according to the results of destructive and non-destructive testing, an increase in the strength of concrete by >15% compared to conventional concrete was found.
Structure formation of plasticized cement systems under heat-moisture treatment
Authors: Leshkanov Andrei , Dobshits Lev , Anisimov Sergey 
Published: July 2020

Abstract
Reducing the water-cement ratio is successfully achieved using superplasticizers (SP). However, their use can reduce the early strength of concrete and reinforced concrete. Heat-moisture treatment (HMT) is the leading way to accelerate concrete strength. The use of the latest SP based on polycarboxylate esters (PCE) allows adjusting the HMT mode, in particular, to reduce the presteaming period duration. The structure formation of cement pastes was studied depending on PCE modification and the presteaming period duration. The authors show PCE effectiveness in terms of reducing the water-cement ratio and joint action with HMT. It was found that the most effective use of low PCE dosages when using HMT. Increasing the amount of introduced SP to 1.2-2.0 % doesn’t lead to significant changes in initial and final setting times of cement pastes. The results of the study of cement stone compressive strength after HMT and on the 28th day, also the density and capillary porosity revealed a slight deterioration of these physical and mechanical properties (up to 5-10 %) when the presteaming period was abandoned. The results of X-Ray Diffraction analysis indicate no significant differences in the mineralogical composition of cement stone, which hardened at the HMT with the presteaming period of 2 hours and without it. The study of the cement stone microstructure showed that the PCE introduction in cement pastes contributes to the stone structure compaction and reduction of the number of pores. There were no significant changes in the cement stone pore structure, depending on the presteaming period duration. The conducted research shows that it is possible to regulate the HMT modes for the hardening of cement systems with SP.
Comparison of autogenous shrinkage measurements by different methods in case of fast-hardening mortar
Authors: Nguyen Ngoc-Lam 
Published: July 2020

Abstract
Autogenous shrinkage in the volume of cementitious materials results from changes in the microstructure and environmental conditions. These deformations can be sufficient to cause premature cracking of structures, especially the fast hardening materials or thin products with large exchange surfaces, such as paving, screeds and cement-glass composite. The appearance of cracks influences the quality and aesthetics of the works. The dimensional variations can be observed immediately after the cement and the water have been brought into contact during mixing. In this research, the endogenous shrinkages of a fast hardening mortar based on ettringite binder were studied with different methods. In this mortar, there is not only the shrinkage phenomenon but also the swelling relating to the early ettringite formation. Therefore, the understanding of the dimensional variation with different measurement methods is very important. The results indicate that the endogenous shrinkage measured by linear methods and volumetric methods are in good agreement. All measurement method well recorded both a quick shrinkage and a swelling phenomenon in the mortar.
Methods of increasing the resistance of concrete to catastrophic failure in a fire
Authors: Semenov Vyacheslav , Bazanov Sergey 
Published: July 2020

Abstract
A characteristic feature of modern building industry is an increase in the construction of high-rise, technically complex and unique objects. A special role in ensuring the safety of objects of this kind is played by fire protection of load-bearing structures. The aim of this work was to review existing solutions aimed at increasing the fire resistance of reinforced concrete structures in order to ensure normative indicators. The research method is theoretical analysis. The issue of protecting reinforced concrete structures from brittle destruction of concrete in a fire is considered in detail. It has been established that a very effective way to maintain the integrity of a reinforced concrete structure during fire exposure is to modify the composition of concrete and control the structure in order to create a certain pore volume in concrete. The available data on the use of such methods are mainly empirical. The influence of qualitative and quantitative indicators of the additives used, the possibility of combining various methods to increase the fire resistance of concrete, modes of heating structures in a fire, and others are not sufficiently studied. These tasks seem relevant and require additional research.
Measures to prevent sewerage odor emissions into the atmosphere
Authors: Ryltseva Yuliya , Orlov Vladimir 
Published: July 2020

Abstract
The transportation and treatment of the urban wastewater involves the formation and emission into the environment of fetid substances: sulfur and nitrogen compounds, volatile fatty acids, aldehydes and ketones. Fetidly smelling odors of a sewage system are formed as a result of the anaerobic biological decomposition of organic substances (proteins, carbohydrates), the presence in the wastewater of sulfate-reducing microorganisms that receive energy through the organic substance oxidation. The article considers the methods for determining harmful gaseous substances through chemical and organoleptic analyses, presents a list of the methods used in the Russian Federation and abroad for determining fetidly smelling substances, as well as investigating the advantages and disadvantages of the measures aimed at fighting against fetid odors. Each of the given methods has been implemented using constructional and (or) operational means. It has been stated herein, that the odor neutralization, a correct choice of operational and technical measures, construction technologies, design and hardware solutions (choice of the equipment) require a preliminary surveying of the objects of fetidly smelling substances along the whole pipeline system as part of thorough design and technological studies. The theoretical significance of the research consists in searching for the causes of the gas fetid smells, their intensity control methods and the ways that prevent formation and minimize negative manifestations by construction and operational means. The practical relevance of the performed studies is in a possible application of the got results by the specialists of the sewage system designing and public utility servicing works.
Cavitation-abrasive wear working collectors of pumps
Authors: Glovatsky Oleg , Ergashev Rustam , Saparov Azamat , Berdiev Mustafo , Shodiev Bobur 
Published: July 2020

Abstract
The main results of the study of hydraulic losses in the suction line and mechanical damages of the impellers of pumps due to cavitation-abrasive wear are given in the article. The scientific task of using theoretical bases for justifying factors affecting the wear rate of pump parts is being solved. On the basis of these theories, a technique is proposed for calculating the wear rate of the elements of the flow-through part of the pumps. During the experimental studies, standard methods of laboratory-bench testing of pumps were used. The operating modes of pumps with minimal wear of their parts are established. Poor hydraulic flow conditions with swirl zones cause an increase in energy losses and a redistribution of flow rates across sections. Wear the parts that are flowing directly proportional to the concentration in the sediment flow, the cube of the flow velocity, the time of action on the pump units. The presence of unsteady vortex regions, especially when the effect of eddy formation increases, leads to fluctuations in the velocities and pulsations of the flow pressure. Cavitation in the pump occurs when the operating modes of the pump differ from the nominal. The increase in volumetric efficiency, the improvement of hydraulic flow conditions to the pump impeller and the reduction of cavitation wear were achieved by the authors in a new pump design that contains guide planes fixed to the throttle plate parallel to the suction nozzle axis with an elastic outer surface. In the same areas of constructive improvement of pump assemblies, it is necessary to search for ways to reduce the negative impact of cavitation and hydroabrasive erosion on the life of pumps.
Interaction of sorption and hydrodynamic phenomena during water filtration
Authors: Vikulina Vera , Vikulin Pavel , Mamina Gyuzyal 
Published: July 2020

Abstract
The paper presents the concept of sorption and surface phenomena, as well as ion exchange. These processes are accompanied by absorption or exchange of ions due to the free energy of the surface layer of the solid phase. It is proposed to consider the process of ion exchange between the solid and liquid phase during filtration. As a solid phase, synthesized loading is used, which is used in various industries. It is noted that the synthesized load has high mechanical strength and chemical resistance. It is indicated that the size and shape of the loading grain affects the ion exchange rate and hydraulic resistance. The dependence taking into account the free energy of the loading surface and the mechanism of ion exchange in the equivalent dependence is given. Technological characteristics of some types of loading are shown. The duration of filtration is determined by the appearance of dissociated ions in the filtrate and depends on the exchange capacity of the load. Static and dynamic exchange capacities are allocated. The relevance, purpose and objectives of the work are formulated. A scheme of fluid motion through the elementary loading layer is proposed for the mathematical description of the process. The increment of substances in the elementary loading layer is described and the conditions of fluid flow around the loading grain of spherical shape are formulated. The reduction of ion concentrations in the elementary layer is mathematically shown. The concentration gradient is obtained as a partial derivative with two variables. The condition of fluid flow around the loading is introduced, based on the processes of hydrodynamics. The flow pattern of the loading elements depends on the Reynolds number. With the help of mathematical and physical analysis, a theoretical dependence was obtained, which relates the initial concentration of the studied substances in water, the metabolic capacity of the load, the hydrodynamic and physical parameters of the flow. The performed theoretical studies allowed to substantiate the conclusions of this work and to formulate a conclusion about the influence of flow hydrodynamics on the change of absorption of substances from water by loading.
Research of operation efficiency of side-stream membrane bioreactors
Authors: Makisha Nikolay , Pervov Alexei 
Published: July 2020

Abstract
Membrane bioreactors nowadays are intensively applied in wastewater treatment worldwide. Such type of treatment systems have a large scope of implementation at facilities of different capacity. A detailed study required to analyze how to implement reconstruction of WWTP by means of membrane equipment that can be located close to existing facilities of biological treatment in small containers without the installation of new capital containers is required. Following that goal there is a certain interest to investigate the operation of side-stream membrane bioreactors under various pressure conditions and to compare its corresponding efficiency and costs (capital and operation). The paper is focused on estimation of operation parameters (backwash frequency, power consumption and specific energy consumption) for three values (1,6 g/L, 2,5 g/L and 7 g/L) of mixed liquor suspended solids (MLSS) if the filtration goes under pressure of 0,5 bar.
Increasing heat efficiency by changing the section area of the heat transfer pipelines
Authors: Arifjanov Aybek , Xodjiyev Nosir , Jurayev Sherali , Кurbanov Кozim , Samiev Luqmon 
Published: July 2020

Abstract
On the territory of our republic, individual boilers are widely used for heating many social facilities in the winter season. The efficiency (efficiency) of these heating boilers is only 70-75%. Sustainable and efficient use of fossil fuels is now becoming a problem not only in Uzbekistan, but throughout the world. In recent years, the results of expert research on the use of solid, liquid and gaseous fuels in heating boilers show that in many countries there is a shortage of fuel and problems with the supply of natural resources to these countries. Of course, given the fact that the process of burning fossil fuels depends on the cross-sectional area of heating boilers, it is necessary to develop recommendations for creating more energy-efficient use of methods to reduce fuel consumption or resource conservation. In our republic, a number of scientific works are consistently carried out to create resource-saving capacities for heat transfer pipelines. In particular, the main content of the dissertation is the development of the introduction of the latest modern scientific methods to increase the efficiency of heating boilers by improving the method of calculating resource-saving heat transfer pipelines. The article presents methods for determining the heat transfer parameters of heat exchangers in laboratory conditions, as well as methods for analyzing the results.
Evaluation of the hydraulic and morfometric connections of the riverbed with using GIS
Authors: Atakulov Dinislam , Babajanov Farrukh 
Published: July 2020

Abstract
Currently, in the country developed models with using on GIS technologies are mainly based on linear schemes of location and mapping of water resources, and there is no database for determining the state of water resources, hydraulic structures, and river and riverbed deformation. The main problem with the use of GIS models in water management is their low accuracy, the fact that created models were based on low-resolution satellite imagery and used old analytical techniques. Models in irrigation systems which used GIS technologies are one of the problems waiting their solution. In this article analyzed possibility of GIS estimation of deformation processes in the river bed (in case of Sokh River). The processes in the riverbed were analyzed based on satellite data and compared with field experiments. Given conclusions based on analysis.
An investigation of human comfort criteria for footfall induced floor vibrations
Authors: Nguyen Tuan H A , Nguyen-Van Hieu , Dao Nhan D 
Published: July 2020

Abstract
Human comfort is becoming a vital serviceability requirement when it comes to design of long-span floor systems, as evidenced by the development of international standards on human exposure to vibrations. This paper discusses experimental findings derived from dynamic testing of a real office floor of steel-concrete composite construction where annoying footfall-induced vibration had been reported by the floor tenants. The fundamental frequency of the problematic floor was determined using measurements obtained from a series of simple heel drop tests. The observed vibration levels of the floor under normal walking excitations was then benchmarked against acceptance criteria suggested by a number of widely used floor vibration design guides. From a human comfort perspective, it is found that the same floor can be classified as unacceptable by some guidelines but deemed extremely acceptable by the others. As response levels are translated inconsistently by various acceptance criteria, designers would hence be placed in a dilemma when deciding whether the existing floor really needs modification to enhance its serviceability.