233 Works

Aerodynamics of building structures for flue gas removal

Vadim Akhmetov, Viktor Shkadov & Pavel Konon
Natural fuel burning in modern heat power plants with flue gas formation is accompanied with harmful environmental impact and potential opportunity of acid fallout. This can lead to local or even global catastrophe under adverse circumstances. High-rise structures combining a smokestack and a cooling tower are used for ecological natural fuel burning. The most important problem of these structures design is to study gas-dynamic behavior of flue gas mixing with warm ambient air flow during...

Track-etched membranes back-flushing and regeneration during the natural water purification

Polina Barashkova & Ludmila Molodkina
Membrane filtration is one of the main methods of local water treatment. Track-etched membranes allow to obtain high-quality purified water due to their high selectivity. During the filtration, the productivity of process can decreases due to the adsorption of components in the pores, pore blockages, formation of sediment layer above the membrane. To restore the productivity, the membrane should be flushed periodically or regenerated chemically. Comparative study of the back-flushing and chemical regeneration after natural...

Modeling the design seismic input in conditions of limiting seismological information

Tatiana Ivanova, Jhy Guan, Olga Nesterova, Sergey Prokopovich, Lybov Smirnova, Aleksandr Uzdin & Dmitry Ivashintzov
The object of the investigations is seismic input models used in structure designing under the conditions of limited seismological information. The aim of the given investigation is to propose a new variant of a seismic input model, which should be generated for the structure under consideration, taking into account main peculiarities of actual seismic excitations. The method of design seismic input generation by means of its presentation as a sum of velocity impulse and multi...

Adhesive dry mix using an amorphous aluminosilicates

Kristina Zhegera, Irina Pyshkina & Georgiy Martyashin
In the paper, it is proposed to use synthesized amorphous aluminosilicates as a modifying supplement in cement adhesive dry mixes. The results of the analysis of the chemical composition and microstructure of the developed supplement based on amorphous aluminosilicates used as a modifying supplement in the recipe of adhesive dry mixes are given. A method for evaluating the shear strength of a solution layer using the device GT 2.2.3 is proposed. The methods of testing...

Thermal-insulation boards from fibrous plant wastes and urea-formaldehyde binder

Tatiana Vahnina, Irina Susoeva & Andrey Titunin
Irreversible waste spinning flax and cotton are sent to landfill or incinerated, it adversely affects the environment, although it is desirable to use plant waste for production, which would be a very positive approach in terms of natural environment. Composite boards of irrecoverable waste from the processing of flax and cotton and urea-formaldehyde binder (UF) can be used as a thermal-insulation material, the development of this composite material is the purpose of this research. The...

Strength of reinforced concrete beams of high-performance concrete and fiber reinforced concrete

Vladimir Travush, Denis Konin & Alexey Krylov
The strength of reinforced concrete beams made of high-performance concrete and fiber reinforced concrete was evaluated in a pure-bending test. The efficiency of using straight steel fiber in bending structures was evaluated. The fracture pattern of models was described. The results of measuring the vertical displacement and crack width are provided and compared to the rated values. The diagrams of stresses and deformation in reinforcement and concrete of models are presented, and their specific features...

Models of direct anchoring of reinforcement in concrete

Larisa Krasotina, Jose Luis Pulido-Delgado & Yurii Krasnoshchekov
When analyzing methods for calculating the anchoring of non-tension reinforcement of reinforced concrete structures, it has been established that there are two types of destruction of concrete in the anchoring zone by shearing or cracking. They are based on the results of research of the strength the adhesion of reinforcement with concrete and testing of specimens with the same type. A new model of anchoring has been created. This model initial moment is the equality...

Rheological behavior of 3D printable cement paste: criterial evaluation

Galina Slavcheva & Olga Artamonova
The extrudability and firm stability are the criterial rheological characteristics of building 3D printable mixtures. From the point of view of classical rheology of disperse systems, the theoretical analysis of the rheological behavior of a cement paste has been analyzed for all stages of 3D printing process. Apparently both the theoretical analysis criteria and technological tools to control rheological behavior of a 3D printable mixture have been justified. The squeezing test is used in the...

Evolutionary optimization of prestressed steel frames

Anatoly Alekseytsev & Sergey Akhremenko
A method for the optimal synthesis of prestressed steel frame structures is developed. The search for a solution is being carried out by applying discrete sets of variable parameters, including cross-sections of structural rods and cross-sections of prestressing tie-rods. It is possible to vary the location of the prestressing system. To optimize the cost of the objects under consideration, an improved meth-od of evolutionary simulation has been used, including a combined scheme for constraints set...

Improvement of the soil deformation modulus using an expandable polyurethane resin

MOHANAD SABRI & Constantin Shashkin
Different methods are used in the field for foundations remediation and improvement of the soil properties, but every method has its advantages and limitations. Moreover, not all the existing methods are able to stabilize the soil and elevate the foundations effectively, regulating the process depending on the desired results. The settlements of the foundations of the buildings and structures lead to negative consequences and controlling the settlements is complex itself essentially in the type of...

Structurization processes of cement composites modified with electrolytic additives

Tatiana Shepelenko, Nicholas Gorlenko & Olga Zubkova
There has been research on the impact of AlCl3 and FeCl3 solutions on kinetics of cement hardening. The research was carried out in two comparative versions, one of which had the saline solutions introduced into cement as gauge liquid (“water–1% electrolytic solution”), the other had them as additives, synthesized in suspensions “cement – (water–1% electrolytic solution)”. It has been stated that the use of AlCl3 and FeCl3 solutions as gauge liquids leads to reduction of...

Indoor environment of a building under the conditions of tropical climate

Jose Castro, Daria Zaborova, Tatiana Musorina & Ivan Arkhipov
This paper is focused on having a different approach to energy efficiency and the way it is employed in industry. It considers the real case of Latin-America where normal temperature during day drastically changes from 0 to 25 degrees. Such temperature variation affects the indoor climate and its comfort. Therefore, one of the important tasks in construction of such regions is the correct choice of building materials for the enclosing structures. This article studies the...

Alkali-activated slag binders from rock-wool production wastes

Vladimir Erofeev, Alexander Rodin, Vladislav Yakunin, Andrej Bogatov, Viktor Bochkin & Aleksej Chegodajkin
The article exposes the results of studies on the production of alkali-activated slag binders from rock-wool production wastes and their composite derivatives, which are resistant to corrosive effects of biological environment. Thermal analysis showed that the structurization in the "rock wool production waste-water-NaOH" system is most efficient with the NaOH/waste ratio of 0.02–0.03, and the main newly-formed phases in the solidified alkali-activated slag composites are low-basic calcium hydrosilicates and analcime. The best values of the...

Flow states in the classical Venturi channel water gauge

Andrey Zuikov, Viktorija Bakunjaeva, Tatiana Artemyeva & Elena Zhazha
The paper relates to the field of hydraulics and is devoted to the study of fluid flow states in a non-submerged Venturi channel. The aim is improvement of the method of hydraulic calculation of the classical Venturi channel. Authors applied experimental methods with the use of hi-tech certified measurement equipment allowing for digital technology-based automated collection and processing of empirical information; calculation and analytical methods. Distribution of depths, velocities and Froude numbers in flow direction...

Mathematical modeling of the colmatation of concrete pores during corrosion

Sergey Fedosov, Varvara Rumyantseva, Igor Krasilnikov, Viktoriya Konovalova & Artem Evsyakov
Pore colmatation plays a positive role, since the decrease in the permeability of cement concrete due to the deposition of insoluble corrosion products in the pores leads to a slowdown in corrosion processes. The mathematical model of concrete pore colmatation based on the mass transfer equations is given, which allows to estimate the depth of corrosion damage of concretes in media of various degrees of aggressiveness. The presented model describes the rate of advance of...

Payback period of investments in energy saving

Alexander Gorshkov, Nicolai Vatin, Pavel Rymkevich & Olga Kydrevich
Authors developed a mathematical model for estimating the discounted payback period of investments for reducing energy resources needed in building's development. Obtained equations allow calculating the projected payback period for investments in energy saving, taking into account the size of the investment, the estimated or actual value of the achieved energy saving effect, the dynamics of energy carriers tariff growth, the discounting of future cash flows, and also a value and a period of loan...

Methods of identification of concrete elastic-plastic-damage models

Andrey Benin, Artem Semenov, Sergey Semenov, Mikhail Beliaev & Victor Modestov
The methodology for identification of mechanical characteristics of the nonlinear material model for concrete, taking into account the elastic-plastic deformation and the damage accumulation under monotonous and cyclic loading, is proposed. The using such improved models of concrete deformation is actual for carrying out finite-element computations of the most important elements of unique and responsible buildings and structures. The proposed methodology is verified for three different types of concrete (B45, B25, B5), including also their...

Soil stabilization and foundation restoration using an expandable polyurethane resin

Mohanad Sabri, Konstantin Shashkin, Evgeny Zakharin & Aleksey Ulybin
The settlement of foundation is one of the main existing problems which face construction engineers during the construction operation processes since the design of a project and through the whole construction life and it leads to bad consequences on the construction. Many methods have been implemented during the last decades to stabilize the soil, lift basements and reduce further settlements. Some of these methods are actively used and effective while others are less effective, have...

Adaptive finite-element models in structural health monitoring systems

Alexander Belostotsky, Pavel Akimov, Oleg Negrozov, Nikolay Petryashev, Sergey Petryashev, Sergey Sherbina, Dmitry Kalichava & Taymuraz Kaytukov
The design and construction of unique buildings, facilities and complexes of “modern” architectural forms and constructive solutions in Russia began less than 20 years ago in the conditions of a shortage of national design codes and experience of such construction. Thus these objects were not provided with proper scientific and technical support and structural health monitoring (SHM) systems. Generally only the instrumental monitoring system, based on results of finite element analysis and comparison with measured...

Mechanical properties of synthetic fibers applied to concrete reinforcement

Andrey Kirsanov & Oleg Stolyarov
Short synthetic fibers are increasingly used for reinforcing of cement-based composites along with metallic and inorganic fibers. In this work, the mechanical properties of short polypropylene fibers with different structures were investigated. The main characteristics, including tensile strength, Young’s modulus, strain at maximum load, and work of rupture were determined. In addition, fiber samples were examined for creep at various loading levels up to 50 % of the tensile strength. Relationship between the creep strain...

Bearing capacity of rafter systems made of steel thin-walled structures in attic roofs

Vladimir Rybakov, Mohamad Al Ali, Anton Panteleev, Kseniya Fedotova & Andrei Smirnov
In the article as an alternative оf strengthening of existing rafters or replacing them by new timber elements there is an offer to consider the replacing timber rafters by elements of steel thin-walled structures (STWS). The authors have proposed the methodology for calculation the statically indeterminate frame structures with the use of force method. Selected sections of rafters made of STWS and timber for various constructive schemes of pitched roofs were analyzed. The results shown...

Earthquake engineering optimization of structures by economic criterion

Nikolai Vatin, Andrei Ivanov, Yury Rutman & Sergey Chernogorskiy
The article deals with an economic optimization problem of structures designed on areas exposed to seismic hazard. Profit (cost-effectiveness) from building usage due its design life-cycle is considered as objective function in this optimization task. Building damage state evaluation procedure and repair cost estimation method are proposed in this study. A criterion and a variable parameter of an optimization problem is suggested here as well. There is an algorithm, which combines seismic computation results with...

Determination of soil deformation moduli after National Building Codes of Russia and Germany

Dietmar Keck, Julia Kalugina & Yakov Pronozin
The paper analyzes the differences in carrying out compression tests in accordance with the regulatory documents of Russia and Germany and subsequent processing of the obtained data. The paper gives the reasons for significant differences in the values of compression and design deformation moduli obtained from the compression test data in accordance with Russian and German National Building Codes. Approximate differences of the above-mentioned moduli have been revealed for various types of soil. The transition...

Self-compacting concrete using pretreatmented rice husk ash

Roman Fediuk, Valeriy Lesovik, Alexandr Svintsov, Aleksandr Mochalov, Sergey Kulichkov, Natalia Stoyushko, Natalia Gladkova & Roman Timokhin
Self-compacting concrete was obtained by partially replacing Portland cement with a previously prepared rice husk ash Preliminary preparation included the thermal treatment of the ash under various conditions. The optimum technology of preparation, allowing to receive a homogeneous concrete mix is revealed. All concrete mixtures were designed in such a way as to have a slump flow of 680 ± 30 mm in diameter, which was achieved by using different dosages of a superplasticizer based...

Stress-strain state of a steel-reinforced concrete slab under long-term

Farit Zamaliev & Marat Zakirov
This article explores the evaluation of the stress-strain state of steel reinforced concrete slabs under the action of long-term loads. The technique of computer simulation for the performance evaluation of steel reinforced concrete slabs under short-term and long-term loads and the results of numerical studies are shown. A unit for long-term tests has been prepared based upon the numerical studies. The mounting locations of instruments for measuring vertical displacements, the label diagram of sensors of...

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