bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sustainable management and technologies for recycled construction demolition waste in Vietnam
Authors: Giang N H , Tan N H , Quang N T , Hien N X , Kawamoto K 
Published: July 2020

Abstract
This study introduces the series of activities and results that are contributing for the CDW recycling industry in Vietnam especially for the implementation of the recently introduced Circular No.08/2017/TT-BXD. The equation for estimation of the amount of CDW generated from building demolition was introduced. New management regulations which are guideline for demolition, sorting, transportation and treatment and new Vietnamese standard for specification of testing and acceptance for CDW recycling materials are highlighted. The properties of recycling concrete from a pilot project were tested. The research designed a circle of recycling business that results from research are contributing for the sustainable management and technologies in Vietnam. These activities and contributions will significantly support for the implementation of Government’s new regulation, reducing the solid waste to meet the National strategies for environment as well as open for a new important recycling industry in Vietnam.
Effect of Carbon Nanotube on properties of lightweight concrete using recycled Expanded Polystyrene (EPS)
Authors: Cong Thang Nguyen , Ngoc Duc Han 
Published: July 2020

Abstract
Expanded Polystyrene based Lightweight concrete (EPS-C) is a lightweight material with low compressive strength and high energy absorption capacity. This type of concrete is mainly applied for heat and sound insulation, towards energy saving and sustainable development. In terms of composition, EPS-C is made from a mixture of cement, mineral additives, water, chemical additives, and Expanded Polystyrene Beads (EPS) which are small hollow spherical, impermeable, and non-toxic balls. In this paper, the EPS particles were replaced with recycled polystyrene particles as aggregates for lightweight concrete. Besides, carbon nanotube (nCNT) was added to improve the properties of the concrete. The experimental results show that (i) it is possible to use recycled EPS aggregate in making lightweight concrete with a density of less than 1200 kg/m3; (ii) the combination of nCNT improved significantly the properties of lightweight concrete, i.e. reducing the water absorption, increasing compressive strength; (iii) lightweight concrete with a very low thermal conductivity, corresponding to 0.152 W/m.°C for a sample with a density of 600 kg/m3.
Fine-grained concrete modified with a multifunctional additive
Authors: Pyataev Eugene , Semenov Vyacheslav , Bilonda Tregubova Elen , Kirushok Denis 
Published: July 2020

Abstract
The article presents the results of comparative tests of samples of fine-grained vibropressed concrete for paving blocks with modifiers for volumetric hydrophobization based on a dispersion of calcium stearate, an emulsion of polysiloxane and an additive based on a mixture of a dispersion of calcium stearate and an emulsion of polysiloxane. To increase the operational reliability and durability of the vibropressed paving slab an important role is played by properties such as water absorption, frost resistance and corrosion resistance. The aim of the work is to research of the effectiveness of complex modifying additives to increase the frost resistance and corrosion resistance of fine-grained concrete for paving slabs. The researches were carried out according to standard methods in accordance with current regulatory documents. It was revealed that the additive based on a mixture of a dispersion of calcium stearate and polysiloxane had the greatest hydrophobic effect. Concrete products based on these modifiers have shown significant improvement in properties such as water absorption, frost resistance and corrosion resistance compared to an unadulterated sample and samples based on calcium stearate.
Geoinformation systems at the selection of engineering infrastructure of pumped storage hydropower for the tuyamuyun complex
Authors: Dzhuraev Kurbon , Nasrulin Aydar , Shadibekova Fotima , Kurbonov Shokhboz 
Published: July 2020

Abstract
In this article, we also consider the results of studying the problems and prospects of using information technologies to ensure the introduction of new innovative approaches to analyze engineering infrastructure of future pumped storage hydropower. This study aims to develop a series of advanced Geographic Information System algorithms to locate prospective sites for pumped storage hydropower. It is possible and useful to use the association of outputs from various scientific researches in one GIS-database as a universal tool for modelling. This demonstrates the site searching algorithms can work efficiently in the identification of off-river pumped hydro sites, allowing high-resolution assessments of pumped hydro energy storage to be quickly conducted on a broad scale. As an example of such an approach can be considered as one interconnected system which combination results of work:
- The examples of the methodology for creating digital maps for information support, for the study of the technical parameters of hydropower and irrigation facilities at the level of Tuyamuyun hydroelectric complex.
- System of digital maps and schemes that can be used in the development of environmentally acceptable modes of operation of in engineering infrastructure of hydraulic accumulating power plants.
- The results of monitoring engineering infrastructure using geographic information systems, digital maps are shown, which allow for the design, repair and repair of hydraulic structures to take into account terrain, hydrography and other factors. Except this in work are offered several objects water systems, in which will possible introduce pumped storage power and are motivated to their technical-economic parameters.
Agent-based simulation for gas and dust emissions assessment during construction: A case study in Vietnam
Authors: Toan Nguyen Danh , Sharmak Walter 
Published: July 2020

Abstract
Construction activities account for a significant amount of greenhouse gases (GHG) and fine particulate matter (PM10) emissions, particularly in developing countries with expeditious urbanization. To achieve sustainability in the construction phase, researchers have made considerable efforts to estimate the emissions accurately. Although several building-level emission databases and related calculation systems have been set up in developed countries, there unluckily remains a vacancy in Vietnam. This study aims to integrate Agent-based simulation (ABS) and process-based life cycle assessment (pLCA) based on construction norms and environmental data available in Vietnam to evaluate the GHG and PM10 emissions under the uncertain and dynamic conditions of on-site construction and supply chains. This method is developed and applied in the case study of a 20-storey building in Hanoi. The results indicate that, among all of the construction equipment, the off-site and on-site transport equipment are the dominant cause for GHG and PM10 emissions. The formwork related-material contributed the most to GHG among the auxiliary materials.
Distribution of the forms of reserves of humus in typical seroms formed in geomorphological areas Tashkent-Keles
Authors: Akhatov Abdusamad , Gafurov Baxtiyor , Jakhonov Azizjon , Khalimbetov Azat 
Published: July 2020

Abstract
The article presents the effect of humic substances on the physical, water-physical, and chemical properties of the soil, as well as the release of various forms of humus reserves (total, potential, near, direct). Each form of reserves of humus formed organic substances and their different differences in the composition of humus the soils of the serozom belt of healed, newly irrigated, and old irrigated soils, accumulation of humus content and distribution in the layers of the section profile, changes in the forms of humus reserves in the genetic horizons of the soil. In a typical irrigated sierozem, the content of potential reserves of humus and in the same row the proximal, direct forms of reserve increases. In the soil profile at a depth of 0-120 cm, the potential reserve of humus ranges from 42,88 % to 29,60 %, the closest one is from 49,32 % to 57,20 %, the immediate reserve from 7,80 % to 13,00 %. These figures show that over the years, the use of soil for irrigated agriculture, the degree of their cultivation and the amount of watering aggregates increased.
Prediction of rejection properties and performance of nanofiltration membranes based on scaling prognosis in drinking water treatment
Authors: Efremov Roman 
Published: July 2020

Abstract
Reverse osmosis (RO) and nanofiltration (NF) are widespread for drinking water production from underground water sources; these techniques are used to reduce hardness, iron, fluoride, ammonium, strontium, nitrate, pesticides etc. At the same time, with high efficiency of removing iron, hardness, fluoride, ammonium from source water, nanofiltration membranes are much less exposed to the risk of calcium carbonate precipitation than the traditionally used low-pressure RO membranes. Usually it is important to predict the rejection properties of membranes not only at the launch time of RO/NF unit, but during all operation period and gradual membrane fouling/scaling. The article presents experimental data on determining membrane selectivity (nanofiltration membrane OPMN-K, Russia) for iron. fluoride and ammonium depending on the TDS, water hardness and the amount of calcium carbonate precipitate in the membrane module. Operational guidance has been developed that allow to determine the costs of chemicals for the operation of NF installations depending on the source water quality and membrane type. The above calculations show that the use of nanofiltration membranes instead of reverse osmosis can significantly reduce the cost of operating groundwater treatment facilities.
Mathematical modelling of operation modes of water intake structures’ cooling reservoirs
Authors: Solovyev Alexander , Solovyev Dmitriy , Shilova Liubov 
Published: July 2020

Abstract
The article provides an overview of the tasks of studying heat and mass transfer in reservoirs with hydraulic flows of circulating water from turbine condensers. The conditions of effective reduction of the temperature of the water from the reservoir via a slotted water intake working on the principle of a hydraulic siphon are considered. The scheme of the slotted siphon-type water intake is presented, as well as its technical implementation. The system of differential equations for the numerical calculation of the parameters of cooling circulating water in reservoirs with siphon culverts is designed. An assessment of the effectiveness of the use of hydraulic slit water intakes in the cooling systems of the recycled water of thermal power plants is contained in the conclusion.
Flow of waste and a method for prediction of demolition waste generation from buildings – A case study in Hanoi, Vietnam
Authors: Nghiem H T , Tran V C , Hoa P D , Kieu T S , Giang N H 
Published: July 2020

Abstract
Being the capital of Vietnam, a dynamic developing country, Hanoi is experiencing a rapid rate of urbanization and economic growth which leads to the continuing increase of construction and demolition activities. In the recent few decades, construction and demolition waste has been accounted for a large amount of solid waste in urban areas, among which demolition waste (DW) is the major content. This study aims to sketch the flow of DW post-demolition, as well as to provide an approach to predict the estimated DW generation in the future in Hanoi. Data of DW generation rate from previous study in Hanoi is combined with statistics of construction in the city to work out a reasonable model of projection of DW for further recommendations for managing this type of waste for sustainable development.
Evaluating the efficiency of Cyperus alternifolius on constructed wetland for the domestic wastewater treatment in the peri-urban area of Northern Vietnam
Authors: Thuy Anh Tran , Duc Ha Tran , Mai Huong Vi Thi 
Published: July 2020

Abstract
Constructed wetland (CW) is an ecological work that can treat wastewater in natural condition. Combining CW with other ecological wastewater treatment works can create a suitable low-cost treatment system for peri- urban areas. The climatic conditions in the Northern region are favorable for the growth of Cyperus alternifolius, one of the commonly planted tree in HFCW worldwide. Our study focuses on the growth of Cyperus alternifolius on HFCW to evaluate the removal efficiency of organic substances and nutrients (BOD5, N-NH4, N-NO3, P-PO4). The dynamical coefficients of decomposition of those matters were also identified. This research employed a wastewater treatment pilot with HFCW planted Cyperus alternifolius and other ecological facilities in a peri-urban area in the North of Vietnam. It was found out that Cyperus alternifolius grew well with a high growth rate. The growth of Cyperus alternifolius enhanced the conversion of organic substances (BOD5) and nutrients (NH4, NO3, PO4) with high decomposition kinetic coefficients. The kinetic coefficient (kBOD) of HFCW in this research was 0.214md−1 which is much higher than the recommendation of Design Standard TCVN 7957:2008. Domestic wastewater after being treated through CW satisfied level A of National technical regulation on domestic wastewater QCVN 14:2008/BTNMT.
Vibration testing for dynamic properties of building floors
Authors: Nguyen Tuan H A 
Published: July 2020

Abstract
The paper presents a comparison of testing methods and post processing techniques for modal properties of a fully furnished chipboard floor and an unfurnished prestressed concrete floor. A thorough modal testing required relocation of transducers among test setups to acquire multiple synchronous measurements of floor response due to heel drop excitation or shaker excitation. The comprehensive experimental data was processed by a specialised operational modal analysis software. On the other hand, a simple testing approach only required records of floor response at a single point due to heel drop. The measured response can be easily analyzed using simple procedures of structural dynamics. Whilst valuable information about the floor modal properties including the mode shapes was obtained using the sophisticated approach, the uncomplicated single-point heel drop test was found to provide reasonably accurate evaluation of natural frequencies and damping ratios for both of the test floors, which verifies the attractiveness of the simple technique. Based on experimental results, both of the floors would be considered as low-frequency floors by commonly used guidelines on human-induced floor vibrations. Furthermore, the effect of fit-out conditions and construction materials on the huge discrepancy between damping values of the two floors was also observed.
Experimental research of service actions influence on elastomeric bearings elastic properties
Authors: Shuvalov Aleksandr , Safina Larisa , Kovalev Mikhail 
Published: July 2020

Abstract
The article includes results of shear test of rubber-metal seismic insulators (elastomers) for different service actions. Research shows influence of low temperatures, material aging and cyclic loads on horizontal stiffness and shear modulus of elastomers. Tests were carried out according to existing Russian and foreign regulatory documents. An insignificant decrease in elastic properties of elastomers is seen after aging and cyclic loading. Influence of low temperatures increases stiffness of elastomers by 23%.
Method of effective parameters for calculations of turbulent swirling flows in engineering constructions
Authors: Akhmetov Vadim 
Published: July 2020

Abstract
The presented article is devoted to the application of the effective parameter method for calculating vortex structures in a turbulent swirling flow. The Navier-Stokes system of equations is used to study flow hydrodynamics, in which the Reynolds number and the swirl ratio are determined based on the concept of turbulent viscosity. The obtained solutions are compared with experimental data.
Dynamic stability and vibrations of thin-walled structures considering heredity properties of the material
Authors: Khudayarov Bakhtiyar , Turaev Fozilzhon , Vakhobov Valizhon , Gulamov Otabek , Shodiyev Sa’dulla 
Published: July 2020

Abstract
Dynamic stability and vibrations of thin-walled structures, taking into account the heredity properties of the material are considered in the paper. Mathematical models were constructed in a two-dimensional statement, using the Karman theory of plane plate strains and A.A. Ilyushin aerodynamic theory. When realizing the physico-mechanical properties of the material of the object, the systems of integro-differential equations (IDE) in partial derivatives with the corresponding initial and boundary conditions are taken as mathematical models of the problems under consideration. The obtained nonlinear partial IDEs using the Bubnov-Galerkin method under considered boundary conditions are reduced to solving systems of nonlinear ordinary IDEs with constant or variable coefficients with respect to the time function. The integration of equations obtained using the polynomial approximation of the deflections was carried out by a numerical method based on the use of quadrature formulas. Based on this method, an algorithm for the numerical solution of the problem was developed suitable for all viscoelastic and elastic elements of thin-walled structures of plate type.
Force properties of longitudinal interaction of the underground pipeline with soil
Authors: Ismoilova Sabida , Loginov Pavel , Khamidov Saidjon , Akbarov Nodirbek , Kumakov Jakhongir 
Published: July 2020

Abstract
The reliability of underground trunk pipelines, in most cases, is estimated based on their strength. When determining the strength of underground pipelines under seismic effects, it is necessary to take into account the forces of pipe-soil longitudinal interaction (the friction force) in calculations. Currently, linear relationships are used to describe the longitudinal interaction forces, where the interaction force is determined depending on the value of the pipe displacement relative to soil. The dependences of the interaction forces on the seismic stress state of soil are not taken into account at all. The paper shows that the interaction forces on the contact surface of an underground pipeline with soil are complex in nature and depend on the wave parameters in soil and in the pipeline itself. Based on the numerical results of solving one-dimensional unsteady-state coupled wave problems for the interacting system “underground pipeline-soil”, the pattern of changes in interaction forces on the pipeline-soil contact surface are determined. It was found that an account for static and dynamic soil pressure normal to the contact surface leads to quantitatively different results than when only static pressure is considered. It is shown that when solving the reliability problems of underground trunk pipelines under seismic effects, first it is necessary to take into account the dynamic stress-strain state of soil in the vicinity of the pipeline.
Forced vibrations of high-rise buildings
Authors: Khudainazarov Sherzod , Mavlanov Tulkin , Qosimov Jakhongir , Nurova Oliya 
Published: July 2020

Abstract
Studies were conducted to analyze the behavior of a high-rise structure on various kinematic effects, taking into account the real geometry, dissipative and nonlinear properties of the structure material. A generalized approach was developed for the dynamic calculation of high-rise structures, and the frequency response characteristics at various points of the structure were built. It was found that nonlinear properties are manifested when the impact can cause significant strain in the structure. This applies not only to the magnitude of the impact intensity, but also to its frequency content. If a non-linearly elastic strain of the material is manifested in the structure, then this leads to a decrease in the amplitudes of points displacements and to an increase in oscillation period compared to a linearly elastic structure under similar kinematic effects.
Evaluating the cable tension results by lift-off and vibration method in Viet Nam
Authors: Duc thi Thu Dinh Nguyen , Huu Hung Nguyen 
Published: July 2020

Abstract
The tension force value in cable of cable stayed bridge is the importance problem and necessary to control in design and service stage. The tension force value in cable is adjusted to ensure the internal force distribution of the structure is most reasonable and to ensure the camber, deflection or general deformation of the entire bridge. This tension adjustment has been performed and verified on many normal cable-stayed bridges. The cable-stayed bridge with more than 2 towers and 3 spans which is the trend of choice in the world as well as in Vietnam with beautiful architectural styles and suitable for use in difficult or limited conditions by topography, this verification is very limited. Recently, Bach Dang cable stayed bridge with 3 towers and 4 spans has opened for service in Viet Nam in Septemper, 2018, the authors have had the opportunity to approach the project and conduct tension measurements in cables by using the vibration analysis method at the time before project has opened for service. In order to evaluate the accuracy of the measurement results, the paper compares the results of tension force in cables that analyzed from measured by vibration method with the values of tension in cables that are directly measured by the lift-off method. These results are also compared with the results in design stage when analysing of bridge structure on software.
Critical factors affecting schedule performance of transportation infrastructure projects in the Eastern Districts of Ho Chi Minh City, VietNam
Authors: Truong T A , Ta T T 
Published: July 2020

Abstract
The study area is composed of Ho Chi Minh City’s East Urban Area including District 2, 9, and Thu Duc where have been oriented by the City’s Government to become the urban intelligence, a place to create Highly Interactive Innovation Districts with innovation development model applied for all aspects of economic, human living, eco environment, smart infrustucture and networking. Transportation infrastructure is one of the most important factors to contribute to build the future smart city in this area. However, in fact, many projects have been delayed directly affacting the development of this area that can slow down the progress of creating intelligent districts. The aim of this study is to investigate factors that influence the schedule performance of transportation infrastructure projects in the East of Ho Chi Minh City to contribute to the project management works. To achieve the goal, the survey conducted with 10 experts and 185 people working in this type of project implemented during the period from 2011 to 2018, using statistical analysis of responses on the attributes and factor analysis to group into six critical factors. Regresstion analysis was also used to test hypotheses and revealed that three groups of factors including Finance; Site compensation; and project fluctuations are strongly affecting the schedule performance. As a consequence, based on the interviews conducted with experienced practitioners, recommendations to deal with these factors are proposed.