133 Works

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...

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...

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...

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...

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...

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...

Approximated methods of estimation of the reliability of framed railway structures of railway bridges

Andrey Indeykin, Sergei Chizhov, Ekaterina Shestakova, Anatoly Antonyuk, Nikolay Kulagin, Vladimir Smirnov, Vladimir Karpov & Dmitriy Golitsynsky
The development of methods for rapid assessment of the reliability of span structures of beam railroad bridges is relevant in connection with the trend towards increasing loads from the reversing freight rolling stock and the speeds of movement on the main transport with a mixed cargo-and-passenger turnover. This problem is especially urgent for the creation and implementation of special technical conditions (STC) for the design of bridges on high-speed lines (BCM), as in Europe and...

Dome houses made of soil-concrete based on local raw materials

Lubov Zakrevskaya, Petr Lubin, Sergey Avdeev, Igor Gandelsman & Sergey Filippov
The work presents the results of research on the strengthening of soil basement in the center of the urban nucleus of Vladimir, which are loam, sandy loam in soft-plastic state, and also sandy loam with silt. The technology of applying the strengthening composition in the soil has been developed. The results of the investigation of physical and mechanical properties of soils and their water resistance have been presented. The microstructure of the concrete has been...

The improving of the concrete quality in a monolithic clip

Anastasia Sychova, Larisa Svatovskaya, Dmitriy Starchukov, Valentina Soloviova & Marina Gravit
The article deals with the possibility of increasing strength, hardness, frost resistance, water and corrosion resistance of concrete. The reduction of its abrasion resistance and water absorption by creating a layer of nonorganic monolithic high-strength clip on its surface is also considered. The possibility of synthesis of such clip by impregnating the concrete surface with a Sol of SiO2 is shown and thermodynamically substantiated. The mathematical dependence reflecting the strength of concrete in such a...

Granulated foam-glass ceramics for ground protection against freezing

Konstantin Ivanov
The problem of seasonal freezing and frost heaving of soils of the engineering structures foundations is considered. For the purpose of thermal protection of soils, a granular inorganic closed-porous material, named granulated foam-glass ceramic is proposed. In the laboratory modeling of seasonal freezing, the dynamics of temperature and deformation, as well as the distribution of moisture over the depth of the soil, were studied in three cases: a soil without thermal insulation, a soil with...

Ultra-high rockfill dam with combination of the reinforced concrete face and clay-cement diaphragm

Mikhail Sainov & Vladislav Soroka
The article deals with design validation of a new type of an embankment dam structural design, i.e. rockfill dam with combination of two types of non-soil seepage-control elements – a reinforced concrete face (in the dam upper part) and a clay-cement diaphragm made of bored piles (in the dam lower part). The dam of the considered design has a number of advantages over classical structural design of concrete faced rockfill dam (CFRD). First of all,...

Thermal cracking resistance in massive foundation slabs in the building period

Aleksandra Bushmanova, Yuriy Barabanshchikov, Kirill Semenov, Ayyyna Struchkova & Sergey Manovitsky
The article deals with the research of the thermal cracking resistance of massive concrete and reinforced foundation slabs of buildings and structures in the building period. The article examines the results of the analysis of the thermal stress state of a massive foundation slab with a fixed thickness of thermal insulation as well as the results of changing the minimum thickness of the insulation on a surface, providing the cracking resistance of the structures on...

Fluid filtration in the clogged pressure pipelines

Elena Loktionova & Dinara Miftakhova
Reducing of the hydraulic characteristics of pressure pipelines in the course of their operation due to corrosion, clogging and other causes leads to an increasing of operating costs. The existing information on the change in the capacity of pipelines under the influence of certain factors is currently insufficient. The aim of the work is to determine the influence of the clogging degree of the pipeline on its throughput. This paper describes the results of hydraulic...

Organizational and technological reliability of the construction process

Vadim Kabanov
Construction projects of buildings and structures, as well as plans of construction and installation works are often subjected to fair criticism from the Pro-producers of the work. Such criticism is that the calculated cost value and long lasting-STI CMP does not take into account the specificity of real contractors. To address these criticisms and proposals were developed for the assessment of such intensity values of SMR production, which most realistically take into account the actual...

Hysteresis of the soil water-retention capacity: estimating the scanning branches

Vitaly Terleev, Aleksandr Nikonorov, Roman Ginevsky, Viktor Lazarev, Issa Togo, Alex Topaj, Kirill Moiseev, Viktoriia Pavlova, Kasim Layshev, Mikhail Arkhipov, Aleksandr Melnichuk, Ielizaveta Dunaieva & Wilfried Mirschel
Designing of underground constructions, such as irrigation and drainage systems, requires engineering surveys. Such surveys include the study of the hydrological conditions of the territory, which are determined by the hydrophysical properties of soils, such as their water-retention capacity. The formation of a hysteresis loop for the soil water-retention capacity occurs because of the variability of meteorological conditions. It is almost impossible to measure all possible scanning branches that fill the gap between the main...

Express-techniques in study of polluted suburban streams

KHristina Il'ina, Nadezhda Gavrilova, Ekaterina Bondarenko, Maria Andrianova & Alexander Chusov
Water samples from streams in suburban region of new builds were analyzed in order to suggest methods and parameters for pollution monitoring. Concentrations of total nitrogen (TN) varied from 0.6 to 9.0 mg/L, ammonium – from 0 to 6.8 mg/L, total organic carbon (TOC) from 8.3 to 21.1 mg/L. Electric conductivity (EC) varied from 80 to 640 mkSm/cm, optical density at 254 nm – from 0.41 to 1.07. Increased concentrations of TN and ammonium at...

Behaviour of concrete with a disperse reinforcement under dynamic loads

Sergey Nikolenko, Elena Sushko, Svetlana Sazonova, Andrey Odnolko & Vyacheslav Manokhin
Disperse reinforcement of concrete greatly contributes to the properties of the latter. Most research has dealt with the properties of disperse reinforced concrete and influence of disperse reinforcement on structures under a static load of one sign or for a regular dynamic load that is not highly intensive. In practice there might well be alternating dynamic impacts that are highly intensive and over the calculated ones, e.g., seismic ones. The paper presents the results of...

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  • 2018

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