202 Works

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...

Инженерная кинематическая теория в приложении к расчету свайных фундаментов

Владимир Сергеевич Коровкин
Автор предложил вариант расчета свайного фундамента с применением инженерной кинематической теории контактного давления грунта. Приведено решение по определению сил трения на боковую поверхность сваи дополнительно зависящее от размеров поперечного сечения внедряемой в грунт сваи. Описано решение по определению реактивного давление грунта на острие сваи или условный фундамент для всего цикла нагрузки. Рассмотрено влияние расположения плиты ростверка в свайном основании на несущую способность конструкции. Учтено взаимное влияние свай на распределение усилий в свайном ростверке. Получено решение...

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....

Lightweight steel concrete structures technology with foam fiber-cement sheets

Vladimir Rybakov, Galina Kozinetc, Nikolai Vatin, Viktor Velichkin & Volodymyr Korsun
Lightweight steel concrete structures (LSCS) constitute an innovative building structure type that can be used both for load-bearing and enclosing purposes. They consist of steel profile – usually galvanized and cold-bent – filled with a monolithic foam concrete with 200 kg/m3 and more density value, and with fiber cement panel sheathing. These structures can be used in industrial and civil buildings as internal and external bearing and enclosing wall structures, and as slabs. According to...

Influence of the compensating device parameters on the underwater pipeline stability

Ksenia Kozhaeva
The definition of rational parameters of the developed compensating device of a triangular shape by calculation and experimental investigation methods is considered in the article. The proposed compensating device with the bent taps use has a more rigid design than the compensating device in the form of a broken bolt. Consequently, the correction coefficient of the compensator form, structurally executed with the use of bent taps is received by calculation and experimental methods for decreasing...

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...

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...

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...

Heat dissipation of cement and calculation of crack resistance of concrete massifs

Ayyyna Struchkova, Yuriy Barabanshchikov, Kirill Semenov & Albina Shaibakova
In this paper, the problems of thermal cracking resistance of massive concrete and reinforced concrete structures during the building period are considered. The calculation results of a research on the effect of hardening temperature on the process of heat dissipation process of concrete are given. The analysis of the thermal stressed state of a massive foundation plate with a fixed thickness of thermal insulation was carried out, the values of the minimum thicknesses of the...

Fire protective dry plaster composition for structures in hydrocarbon fire

Marina Gravit, Elena Golub & Sergey Antonov
The result of the combustion of fire hazardous materials at the facilities of the oil and gas complex is extensive fires, characterizing the rapid temperature rise, and as a result the destruction of load-bearing structures occurs. The dynamics of the development of such fire type requires a different approach to test the structures in order to determine the limit of fire resistance. The article presents European and American normative documents that contain methods for testing...

Productivity of microalgae as biofuel for bioadaptive systems of facades

Ekaterina Zalata, Iurii Shavrov, Kseniya Strelets & Maria Emelyanova
Microalgae are one of the promising fuel sources and many specialists associate it with the future of alternative energy. A promising area of application of photobiological devices is their conjugation with the architectural covers of a building and formation of bio-adaptive facades. The determining criteria for the organization of the microalgae biomass production process in the facade structure is solar radiation, ratio of light and dark growth phase and ambient temperature. The goal of this...

The effect of particulate reinforcement on strength and deformation characteristics of fine-grained concrete

Sergey Klyuev, Alexander Klyuev, Abakar Abakarov, Elena Shorstova & Nina Gafarova
One of the options to improve the reliability and increase the service life of concrete structures can be a reinforcement of the total volume of fine-grained concrete with different fiber types. The article presents the results of complex researches on studying of influence of parameters of the dispersed reinforcement (fiber, length and type of fiber, dosage by volume) and the material of the fibers of strength of disperse-reinforced fine-grained concrete on a stretching at a...

Water vapour by diffusion and mineral wool thermal insulation materials

Nikolai Vatin, Igor Pestryakov, Shukhrat Sultanov, Olamipe Ogidan, Yuliya Yarunicheva & Anastasia Kiryushina
This article is aimed at determining the absorption of moisture by diffusion of mineral wool and polyisocyanurate over a long-term period. The task of increasing the thermal insulation properties of enclosing structures is most relevant for the erection of new buildings or structures, as well as for the repair of existing. The method models operating conditions in which thermal insulation product absorb moisture from both sides at high relative humidity of air (100%) and pressure...

Energy performance of domestic hot water systems

Dzintars Grasmanis, Daniil Sovetnikov & Daria Baranova
Residential sector consumes 70 % of the district heat. The domestic hot water system consumes 27 % of the total thermal energy consumption in these buildings in Riga. According to the mandate of the European Committee for Standardization (CEN) European standards for assessment of the energy performance of buildings have been developed. CEN standards give different methods and default values for calculations and procedures for energy performance assessment. Taking into account national or regional regulations...

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....

Behavior of a hollowed-wood ventilated façade during temperature changes

Gabriel Vieira, Mikhail Petrichenko, Tatiana Musorina & Daria Zaborova
The Ventilated Façade System is a reasonably new technique, which was developed in Europe with the need of cost savings from the energy for cooling and heating of constructions. This system, established in the 1960’s, was an acknowledged as a constructive innovation both for esthetics and functional aims. Therefore, its use has spread not just during buildings’ retrofit but also in new constructions. Despite this fact, the applicability of wood with a hollow through it...

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...

Crack self-healing in clay-сement concrete diaphragm of embankment dam

Stanislav Sosky, Natalia Orlova & Aleksej Velichko
The article presents the results of the analysis of seepage flow character in an embankment dams with impervious diaphragm made of clay-cement concrete, using the Gotsatlinskaya HPP as an example. The process of slits colmatage was considered in the clay-cement-concrete diaphragm (CCCD), that be caused in the zone of tensile forces or by seismic actions. Mathematical models build in two-dimensional and three-dimensional formulation to study the characteristics of flow in subvertical and subhorizontal cracks. By...

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...

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...

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