59 Works

Efficiency of activation of mineral binders in vortex-layer devices

Ruslan Ibragimov, Evgeny Korolev, Rashit Kayumov, Timur Deberdeev, Vladimir Leksin & Andina Sprince
Improving the efficiency of construction composites is a relevant problem for modern-day material science. One of the ways to solve the problem consists in activating the binders by means of vortex-layer devices. Mathematical transformations produced a formula for calculating the dependency of the number of ferromagnetic-particle collision on the number and velocity of such particles, as well as on the device chamber fill factor. The results obtained by applying the proposed formula differ from D.D....

Reliability estimation of industrial building structures

Sergii Pichugin
The article is devoted to solving the problem of the reliability of industrial building structures: crane and roof beams, columns, redundant building systems. For this aim, the probabilistic method of structural reliability estimation is developed after the criterion of bearing strength, in which the main component of structure reliability is faultlessness. The method takes account of the random loads and material strength, loads joint action, the specific character of work and failure elements, nodes and...

Ultimate state of the support zone of reinforced concrete beams

Vladimir Travush, Sergey Krylov, Denis Konin & Alexey Krylov
A brief review of actual methods of calculation of the shear forces is performed; the calculated dependences are analyzed and their estimation is given. The shortcomings of the methods are noted, the main one is the empirical approach to the solution of the problem. The features of destruction of reinforced concrete elements along an inclined section are considered; the mechanism of destruction, on which the actual normative documents are based, is analyzed. A method of...

Properties and thermal insulation performance of light-weight concrete

Tang Lam, Dinh Tho Vu, Vu Kim Dien, Boris Bulgakov & Elena Anatolyevna Korol
The building energy performance is becoming increasingly important, because of environmental restrictions and rising costs of fuel end energy. Therefore, improve the thermal insulation performance of wall covers of buildings is crucial. The present study evaluated the combined effects of two types of materials of expanded polystyrene (EPS) beads and unprocessed fly ash (FA) in Vietnam on properties of light-weight concrete (LWC). The calculation of mixture proportions of LWC is applied in accordance with the...

The building extension with energy efficiency light-weight building walls

Vitaly Sergeev, Mikhail Petrichenko, Darya Nemova, Evgeny Kotov, Darya Tarasova, Anna Nefedova & Anatolijs Borodinecs
he effective use of plan area is more crucial in high-rise buildings, since they are mostly narrow compared to the conventional buildings. The measurement of the overall thermal transmittance of lightweight steel-framed walls, including the effect of thermal bridges due to metal structure, is a challenge for designers, engineers and energy audits. In this paper the energy efficiency light-weight wall technology for over story of buildings was considered. In this work was developed a mathematical...

Stress-strain behavior of welded joints in railway girders

Sergey Bokarev, Kirill Zhunev & Andrey Usol’tsev
A metal construction with welded joints often fails under repeated loads by fatigue. Fatigue cracks at welded joints occur because real stress-strain behavior of welded joints is not taken into consideration by standard design. The article is devoted to the stress behavior determination of welded joints in railway girders under external loads and residual stresses. Design deficiencies and technological features of welded girders were identified. These features may increase stresses at welded joints and decrease...

Concrete with recycled polyethylene terephthalate fiber

Aleksandr Kiyanets
The purpose of this study was to obtain the data on the influence of fiber from the products of recycled polyethylene terephthalate (PET) on the strength properties of fiber-reinforced concrete. In the experiments, used the direct product of industrial recycling of plastic bottles (flex), as well as specially prepared smooth and ribbed fiber from the same raw material. The influence factors were chosen fiber length from 1 to 5 cm and the amount of fiber-from...

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...

Luminance distributions in the tropical sky conditions

Nguyen Phuong
Lighting engineering in construction is a complex scientific field, which requires the amalgamation of knowledge in the field of daylighting, construction and architecture, as well as other areas, including the humanities. Many studies have proven the benefits of natural light on health, activity, visual well-being and human productivity. Global environmental issues and the sustainable development movement require architectural design to achieve maximum energy efficiency. For all intents, daylighting calculations depend on the luminance distributions of...

Cement based foam concrete with aluminosilicate microspheres for monolithic construction

Aleksei Steshenko & Aleksandr Kudyakov
The present paper investigates cement foam concrete of natural hardening with aluminosilicate microsphere made from bottom ash waste from Seversk Heat and Power Station in Tomsk Region. The relevance of the given study is conditioned by the necessity to provide the required process parameters of mixture for transportation and laying the formwork, as well as providing strength and thermal and physical characteristics of wall structures for economy-class housing construction. Porous microsphere from bottom ash wastes...

Fireproof suspended ceilings with high fire resistance limits

Marina Gravit, Elena Golub, Denis Grigoriev & Igor Ivanov
Suspended ceiling is an effective way to fire protection of horizontal structures with steel beams due to its lightness, reliability and functionality. Three designs of fireproof suspended ceiling with silicate plates on cement binder are considered. A detailed description of the tested structures is given. Experiments were carried out to determine the fire resistance of the samples. The results of fire tests on suspended ceilings under standard fire temperature regime are presented in this study....

Biostable silicic rock-based glass ceramic foams

Vladimir Erofeev, Alexander Rodin, Aleksej Kravchuk, Sergej Kaznacheev & Elena Zaharova
The search for the possibility of expanding the resource base through the use of local rocks, as well as reducing the cost of final product, is one of the scientific research areas in the field of obtaining foam glass-based building materials. The aim of the research is the development of compositions and recommendations for the production of silicic rock-based glass ceramic foams. These studies will allow to create strong and durable building materials with low...

Fiber concrete for the construction industry

Sergey Klyuev, Alexander Klyuev & Nikolai Vatin
The article considers the use of dispersed concrete reinforcement. The efficiency of reinforcing of concrete by a fiber is proved as its strength and deformative characteristics increase. For receiving composite binders were used: Portland cement of TsEM I 42.5H GOST 31108-2003 (Russian State Standard), blast furnace granulated slag with Mo =1.14 and Ma = 0.2, mineral plasticizer Tricosal 181 softener in essence supplementing particle size distribution knitting, waste of wet magnetic separation of ferruterous quartzites...

Scheduling workflows for scattered objects

Yuri Kalugin & Roman Romanov
As a rule, the task of optimal scheduling, including reducing the total duration of the project occurs when developing and adjusting schedules. The essence of flow shop scheduling problem on the scattered objects with the use methods and models calendar planning was presented. The branch and boundary method were proposed as an exact method for determining the optimal permutation including the scheme of branching and rules for determining the lower boundaries. Heuristic algorithms for determining...

Rational use of HPSFRC in multi-storey building

Karina Buka-Vaivade, Janis Sliseris, Dmitrijs Serdjuks, Leonids Pakrastins & Nikolai Vatin
Fibres improve concrete properties that can be used to solve the problem of limited resources. This research includes the numerical comparison of high-performance concrete (HPC) and high-performance steel fibre reinforced concrete (HPSFRC) behaviour. The numerical comparison is based on the analyse of stress-strain curves of considered materials. The limits of rational use of HPC and high-performance steel fibre reinforced concrete HPSFRC have been determined based on typical stress resultants values acting in the elements of...

Damage prediction model for concrete pavements in seasonally frozen regions

Qianqian Zhao, Peifeng Cheng, Jianwu Wang & Yuwei Wei
Vehicle loads and environmental differences are the key technical factors in the model construction of concrete pavement damage prediction. According to the data of the 168-month actual number of actions of different vehicle axle types, average temperature, average wind speed, rainfall, snowfall and days below 0 ℃ collected from the Mudanjiang-provincial section of the He-da highway in China, the broken slab ratio of cement concrete (DBL) was calculated. Cracking rate(CRK) and environmental factor(SF) were introduced...

Additional load on barrel vaults of architectural monuments

Anay-Khaak Kaldar-Ool, Vladimir Babanov, Boris Allahverdov & Svetlana Saaya
In old buildings, which are architectural monuments, the stone three-centered barrel vaults and arches have been often used. In case of reconstruction of old buildings, it becomes necessary to increase the load on these elements. Calculation of additional load is based on instrumental examination of the vaults. While creating an analytical model of a barrel vault, it is necessary to use the experimental results of determination of the vault geometric parameters and material strength characteristics....

Residual resource of a one-storey steel frame industrial building constructed with bridge cranes

Tatiana Zolina & Pavel Sadchikov
The scheme of an integrated approach to the study of changes in the stress-strain state of the frame one-story industrial building constructed with bridge cranes, caused by accumulation of damage caused during the operation. The algorithm has been developed for estimating and predicting the residual resource of a production facility on the basis of processing the results of a series of surveys. It allows to obtain the values of reliability indicators in the correlation approximation...

Ventilation impact on VOC concentration caused by building materials

Jurgis Zemitis, Anatolijs Borodinecs & Austris Lauberts
Many of building products emit volatile organic compounds (VOCs) therefore reducing the indoor air quality. The emitted amount and pollution type depends on each specific source. This paper analyses the VOC concentration change caused by such sources as sprayable window cleaner, aroma candles, sprayable air refresher, waterborne acryl-based paint, solvent based paint and acrylic based hermetic sealant. The tests are done at both closed and ventilated climatic chamber conditions. The results show that three different...

Compatibility of precast heavy and monolithic lightweight concretes deforming

Alexander Koyankin, Valery Mitasov & Trofim Tskhay
Safe performance of connecting joint applied to different concrete ages is highly important when joints is placed in composite structures since joint is involved in mutual deformation of precast and monolithic concretes. This experimental study was carried out to determine how type of joint influence on it bearing capacity when perceiving shearing forces. The tests were carried out on a specially manufactured horizontal bench and a vertical press, which provided a shear force in the...

Thermal protection of low-rise buildings from light steel thin-walled structures

Terentii Kornilov & Alexsandr Nikiforov
Thermal protection providing of frame buildings in the extreme conditions of the Far North depends on air infiltration. Elements of buildings frame on light steel thin-walled structures (LSTS below) technology – lightweight, thin-walled steel profiles make up multiple thermal bridges. The basic principles of designing the exterior walling of low-rise buildings from LSTS in the Far North are developed with taking into account the increased air infiltration and the heat transfer components and assemblies. The...

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...

Probabilistic seismic assessment of concrete frame with mass irregularity

Elahesadat Hashemi, Ali Kheyroddin & Mohsen Gerami
As mass irregular structures are more influencing on the behavior of the structures, it is investigated the effect of these irregularities according to the probabilistic approach. Comparison of seismic performance of ten regular and irregular 6-story concrete special moment frame is done, based on the Mean Annual Frequency (MAF) method. The probability of collapse in all irregular models has exceeded the 1 % that is permissible value specified in the ASCE/SEI 7-16. The largest rate...

Water permeability of the polymer screen with a system of slits of hydraulic structures

Yuri Kosichenko & Oleg Baev
The calculation of water permeability through a system of defects (long narrow slits in the junctions) in the screen is considered based on the filtration model. Its structural layout and description of the model main elements are given. The solution is carried out for the plane formulation of the problem by the methods of the filtration theory using the method of conformal mappings and the velocity hodograph method. A distinctive feature is the study of...

Local fuse to improve the behavior of concentric braces

Ali Kachooee, Mohammad Ali Kafi & Mohsen Gerami
The concentrically braced system is one of the most common lateral load bearing systems among steel structures. These systems have remarkable lateral stiffness and strength, but their compressive buckling prevents them from being ductile and absorbing optimal energy. In this study to solve this problem, by using numerical and experimental studies, a heuristic method is presented. In this method, a local fuse is used along the rectangular hollow section brace. This fuse is mounted by...

Registration Year

  • 2019
    59

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  • Text
    59

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  • Magazine of Civil Engineering
    59