240 Works

Методы оценки срока службы асфальтобетонного покрытия

Михаил Александрович Завьялов & Андрей Михайлович Кириллов
В предыдущих исследованиях была показана возможность учета энергетических изменений, происходящих в системе дорожное покрытие – транспортное средство, и их вклад в формирование научно обоснованной системы назначения сроков ремонтных работ. В связи с этим также перспективным является развитие результатов работ, в которых приводится анализ зависимостей термодинамических функций дорожного покрытия от времени эксплуатации. Несмотря на то, что ранее был сформулирован термодинамический подход, удобные расчетные формулы для определения межремонтного срока службы покрытия отсутствуют. На основании анализа полученных соотношений,...

Strength evaluation of the Prussian vaults made from brick aggregate concrete

Romuald Orlovich, Rafal Nowak, Nikolai Vatin & Vladimir Bespalov
The behavior of Prussian vaults of brick aggregate concrete differs both from the behavior of brick vaults and classical flat slabs. Such vaults are particularly susceptible to physical damage and deterioration. To determine the real bearing capacity of the vaults, the authors not only performed the in-situ determination on several sections with deflection control, but also numerical simulations of the multi-span system of Prussian vaults in the program complex Abaqus. Moreover, experimental comparisons between damaged...

Composite binders for concrete of protective structures

Roman Fediuk, Valeriy Lesovik, Aleksandr Mochalov, Kamil Otsokov, Irina Lashina & Roman Timokhin
The composite binders, obtained as a result of joint mechanochemical activation of Portland cement, rice husk ash, quartz sand, screening of limestone crushing and plasticizing additive were considered. The type of binder influence to the rheological and mechanical characteristics of self-compacting concrete mixtures and fiber-reinforced concrete is established. By scanning electron microscopy, it was revealed that the application of the developed binder leads to the compacting of the microstructure, with lamellar and acicular neoplasms filling...

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...

The temperature waves motion in hollow thick-walled cylinder

Oleg Samarin
A hollow cylinder with thick walls is one of the most complex objects to calculate the un-steady temperature field, so this field is the least studied. However, such objects are found in many modern constructions of systems of generation and distribution of heat. In the proposed work it deals with the study of propagation of temperature waves in the wall of the hollow cylinder after a sudden temperature change of the internal environment, fuss-causes upon...

Purification of hot water by zeolite modified with manganese dioxide

Alexey Chechevichkin, Nikolai Vatin, Vyacheslav Samonin & Mikhail Grekov
A new material is proposed for complex purification of hot water from iron and hydrogen sulphide – natural zeolite modified by manganese dioxide. It has been shown experimentally that this filtering material has high efficiency of water purification from iron and hydrogen sulphide, low mechanical degradability during operation, as well as low water consumption for washing during regeneration of the filtration media. The complex cleaning of hot water is proposed to carry out by means...

Interaction process on the phases interface “bitumen – dispersed phase from cement stone”

Sergei Inozemtcev & Evgeniy Korolev
The results of the study of the effect of the main properties of mineral fillers from cement stone with different degrees of hydration, phase composition and pore volume characteristics on the properties of the bitumen-mineral binder are presented. Dependencies of the influence of mineral filler on the basis of cement stone on the basic parameter of the structure of bitumen-mineral binders-the thickness of the adsorption-solvate layer of bitumen, which was established using the rheological method....

Fire resistant fibre reinforced vermiculite concrete with volcanic application

Tolya Hezhev, Artur Zhurtov, Ayes Tsipinov & Sergey Klyuev
The results of studies on the development of vermiculite concrete composites with application of volcanic ash and pumice are presented. The composition of cement fibre vermiculite concrete fire resistant composites are offered, which allows reducing the consumption of Portland cement and simultaneously increasing their flame retardant properties. The use of basalt fibers in composites can improve the strength, fracture toughness and fire retardant properties of the coating due to the perception of tensile thermal stresses...

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...

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...

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...

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...

Двусторонне облученные трековые мембраны в локальном водоснабжении

Полина Сергеевна Барашкова, Людмила Михайловна Молодкина & Мария Дмитриевна Коровина
Мембранная фильтрация является одним из основных методов, применяемых в индивидуальном и маломасштабном водопользовании. С помощью трековых мембран, обладающих высокой селективностью, можно получать очищенную воду высокого качества. Но при их использовании необходимо обеспечивать прочность трековых мембран, что является актуальной проблемой. В работе проведено сравнительное изучение процесса фильтрации природной воды с использованием стандартной трековой мембраны толщиной 12 мкм и новой, более прочной, мембраны толщиной 20 мкм, облученной с обеих сторон. Обе мембраны изготовлены НПФ «Трем» (Санкт-Петербург). Диаметр...

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...

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...

Composition and rheological characteristics of bitumen in short-term and long-term aging

Bagdat Teltayev, Cesare Rossi & Saltanat Ashimova
This paper investigates the impact of sequential short-term and long-term aging of blown bitumen of the grade BND 70/100 on its mechanical characteristics in the temperature interval from 76°С to -36 °С. Group chemical composition of the bitumen has been determined by the method of liquid adsorption chromatography by the chromatograph “Gradient M”. Short-term aging has been performed in the vertical rolling thin film oven (RTFOT) under the standard of AASHTO T 240-08, and the...

Dynamic interaction of high-speed trains with span structures and flexible support

Vladimir Smirnov, Ekaterina Shestakova, Sergei Chizhov, Anatoly Antonyuk, Alexander Lediaev, Andrey Indeykin & Sergey Evtukov
To ensure reliable and safe operation of the bridge structure throughout the life cycle, it is necessary to analyze and take into account many important factors, including the interaction of the main load-bearing structures. The presented work has new theoretical information, which gives the main provisions in the field of design of artificial structures for high-speed railroads. To analyze the system of a multi-span split bridge design using flexible intermediate supports of a flyover type,...

Method of calculating the optimal sand content in normal-weight concrete

Leonid Dvorkin
In the practice of proportioning concrete compositions, the optimum sand content in a mixture of aggregates is usually found empirically. The disadvantage of this approach is the considerable complexity and duration of the required tests. The aim of the work is to develop a calculation methodology for finding the content of sand in the normal-weight concrete, taking into account the optimality criteria given. Based on the well-known theoretical concepts, the design equations are substantiated for...

Numerical simulation of ventilated facades under extreme climate conditions

Mikhail Petrichenko, Evgeny Kotov, Darya Nemova, Darya Tarasova & Vitaly Sergeev
To reduce the costs of building operation, it is necessary to provide for the use of energy-saving technologies at the stage of building design. This allows efficient use of material and energy resources, minimize costs during the design and construction of buildings and structures. One of the energy-saving technologies widely used in construction is the use of ventilated facade systems. Its application in difficult climatic conditions of many regions of Russia requires improvement and refinement...

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...

Stress-strain state of clamped rectangular Reissner plates

Mikhail Sukhoterin, Sergey Baryshnikov & Tatiana Knysh
The paper focuses on obtaining numerical results for a rectangular Reissner plate with clamped contour under the influence of a uniform load using the iteration superposition method of four types of trigonometric series (correcting functions). The initial function of bendings is selected as a quartic polynomial which turns into zero on the contour and is a specific solution to the main bending equation. Discrepancies in rotation angles from the initial polynomial are eliminated in turn...

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...

Silica fumes of different types for high-performance fine-grained concrete

Aleksandr Rassokhin, Andrey Ponomarev & Oleg Figovsky
One of the most often and successfully applied admix as a part of the modified concrete is active amorphous silica fume. The increased practical interest in this admix has led to emergence in the market of various producers and also to emergence of different types (brands) of the silica fume produced from various raw materials with use of various technologies. At the same time their makeup, dispersion and content of silicone dioxide drastically ranges. It...

Метод расчета периода контроля оборудования инженерно-технических систем

Владимир Стальевич Солдатенко, Владимир Александрович Смагин, Ярослав Николаевич Гусеница, Василий Иосифович Гера & Тамара Николаевна Солдатенко
Рассматривается модель и процедура оптимизации периодов контроля и профилактических мероприятий применительно к оборудованию инженерно-технических систем. Данный подход реализуется на основе выполнения условия минимума средних потерь целевого использования оборудования. Указанные потери возможны из-за неоптимальной периодичности контроля и профилактики элементов инженерно-технических систем. В статье рассматривается подход, используемый в теории информации для минимизации снижения ценности информации по причине перерывов при ее передаче. Особенностью предложенной подхода является использование целочисленного квантования межконтрольных интервалов и учет случайной продолжительности периодов эксплуатации оборудования....

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...

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