213 Works

The phase composition and properties of aluminate cements after early loading

Yuriy Galkin, Sergey Udodov & Lada Vasil'eva
It is widely recognized that the effect of loading at the early stages of hardening enables to increase strength characteristics of cement systems and composites based on them. Of particular interest is a study on the effect of compression of aluminate cements on physicomechanical characteristics, hydration process and phase transformations. The research focuses on maximum compressive and flexural strength, the peak intensity of the main phases and hydrate products, characteristics of DTA curves after early...

Метод управления освоенным объёмом в контроле сроков проекта

Анна Викторовна Вахрушкина, Анастасия Вячеславовна Мишакова & Ксения Дмитриевна Борщева
Статья посвящена методу управления освоенным объёмом, в ней описаны основные инструменты данного метода, особое внимание направлено на показатели отклонения сроков проекта. Также выявлены причины отказа от использования метода на практике. Выявлена основная проблема метода управления освоенным объёмом – невозможность его применения для контроля сроков проекта, проанализированы пути решения этой проблемы, предложенные У. Липке. В качестве примера был рассмотрен проект, состоящий из 8 работ. Было проанализировано три случая возможного разделения затрат между критическими и некритическими работами....

Burnt rock of the coal deposits in the concrete products manufacturing

Mikhail Kuz'min, Leonid Larionov, Victor Kondratiev, Marina Kuz'mina, Vyacheslav Grigoriev & Alina Kuz'mina
The paper presents the results of the comprehensive study of the composition, properties and structure of the burnt rock found at the mining dumps of Cheremkhovo coal deposit (Irkutsk region, Russia). In the course of laboratory research, which included optical crystallography, there have been established the reasons accounting for the extent of burnt rock activity when in contact with cement during the cement stone formation. The benefit of the burnt rock as an active mineral...

The critical ventilation velocity for transverse double fires in tunnel

Qiuyi Zhang & Guihong Pei
The critical velocity of longitudinal ventilation is one of the most important parameters in tunnel fires. Most previous studies simulated fire scenarios in which only one fire source exists in the tunnel. However, the critical velocity will change under the condition of transverse double fires. In this study, the critical ventilation velocity under the transverse double-fire condition compared with the single fire source was analyzed by using the Fire Dynamics Simulator (FDS). The results show...

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....

Refined finite element of rods for stability calculation

Yury Tyukalov
The article deals with the application of a rod finite element with five degrees of freedom in a node to solve problems of stability of planar rod systems. In the presented finite element, additional degrees of freedom are introduced in the nodes in the form of curvature and axial deformation. Additional degrees of freedom provide a higher degree of approximation of displacements and deformations along the length of the finite element, which can be useful...

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...

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...

The formation of the seabed surface relief near the gravitational object

Vladimir Lebedev, Igor Nudner, Nikolay Belyaev, Konstantin Semenov & Dmitry Schemelinin
During the interaction of waves and currents with objects established in the shallow offshore areas, scour of their base may occur. At the same time, it is always necessary to exclude the appearance of significant seabed scour near supporting parts of gravity-type platforms during the process of their design. The article presents the results of experimental studies of processes occurring under the impact of flows of various types on gravity-type structures and their foundations. The...

Constructive-technological decisions in regulating the flow of atmospheric precipitation

Olga Degtyareva, Georgy Degtyarev, Nikolai Lavrov & Djouhar Aliev
Practically all sources of fresh water suitable for agriculture, water supply to the population and vacationists, as well as for industrial development on the Black Sea coast of the Caucasus either have completely exhausted themselves or are on the verge of their possibilities. Further development of the region is directly related to the resolution of this problem. The solution of the problem is possible when the system for regulating precipitation flow is implemented. The proposed...

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...

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...

Construction of autonomous buildings with wind power plants

Vasily Titkov, Amangeldi Bekbayev, Toleuhan Munsyzbai & Kalizhan Shakenov
The use of renewable energy converters, including local wind power plants to provide private households and houses with electricity, is gaining popularity, especially in countries where there are appropriate state subsidies. In this paper considered approach to the use of the building roof in the conversion of the kinetic energy of the incoming wind into electrical energy by a closed wind power plant (WPP). The construction of the WPP and the roof are converted into...

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...

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...

Heating and charring of timber constructions with thin-layer fire protection

Evgeniy Polishchuk, Andrey Sivenkov & Samat Kenzhehan
The results of fire tests of constructions (beams) with fire retardant film coating in one-side fire effect under standard temperature fire regime are shown in this article. Intensity dynamics of samples heating and their charring process in thickness and along the perimeter were chosen as the key indicators. It is shown that the use of thin-layer non-swelling fire retardant coatings does not influence the intensity dynamics, in case of high-temperature exposure generates from the side...

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...

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...

Ventilated facade integrated with the HVAC system for cold climate

Mikhail Petritchenko, Darya Nemova, Evgeny Kotov, Darya Tarasova & Vitaly Sergeev
The application of convective heat transfer for air mass displacement in ventilation systems without the mechanical draft (integration of Double Skin Facade with HVAC Systems of the building) has a real practical perspective for Building energy performance. The purpose of this article is development of the theory of heat and mass transfer in capillary-porous media, air flows and building structures. The engineering purpose is а concept development of a closed ventilating circuit with convective heat...

Compressed-bent masonry walls reinforced with composite materials

Romuald Orlovich, Vladimir Bespalov & Valery Derkach
Despite the wide spread of surface composite reinforcement of masonry structures, there is not enough information concerning methods of calculating such reinforced structures in the actual normative literature. The article proposes a numerical model for estimating the effect of composite reinforcement on the bearing capacity of a compressed-bent masonry wall which is constructed on the basis of experimental studies of walls from cellular concrete blocks. The numerical model takes into account the plastic work of...

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...

Implementation of pulse heat supply for dependent connection of customers

Andrey Makeev
This article deals with organization of pulsed and fluctuating circulation of heat-carrying agent in separate sections of heat supply system with dependent connection of customers. These types of oscillatory motion of the heat-carrying agent are proposed to be carried out in a self-sustained operation on the basis of the hydraulic ram operation principle. The relevance of the subject-matter is determined by the influence of oscillating flows on the intensity of heat exchange processes and by...

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...

Strength of composite steel and concrete beams of high-performance concrete

Vladimir Travush, Denis Konin & Alexey Krylov
A brief review of the use of high-performance concrete in monolithic structures in Russia in recent years is made; the last experimental work for the study of high-performance concrete in composite steel and concrete structures is observed. Strength assessment of composite steel and concrete beams has been carried out by a pure-bending test. The models destruction pattern has been described. Vertical displacement and crack width measurement results have been conducted; comparison with the standardized values...

Shielded retaining wall in the form of substandard rack-mount frame

Aleksandra Smolenkova, Vladimir Korovkin, Nina Orlova, Kirill Ragulin & Aleksandra Kuzina
The article gives a practical implementation of the engineering method for calculation of different types of retaining walls. The main provision of the method is to provide the construction calculation model as a combination of construction elements with the respective conditions of their fixing. The calculation model of shielded retaining wall (covered type of sheet pile wharf) is proposed in the form of substandard rack-mount frame where resilient ground attachment is accepted instead of rack...

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