bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heavy concrete with mineral additive tripoli
Authors: Lukuttsova N P , Golovin S N , Artamonov P A 
Published: December 2019

Abstract
The research results of the effect of active mineral additive tripoli of the deposits of Grishina Sloboda of the Bryansk region on the strength of heavy concrete are presented in the article. The chemical composition and structure of the sedimentary rock tripoli are studied. It is found that the tripoli grinding to the specific surface area of 340 m2/kg leads to the production of concrete class B35 with its content of 5% and class B30 with its content of 10%. The extreme dependence of the concrete strength on the tripoli content after 7 and 28 days of hardening is established. It is shown that the diminution in the sand fineness modulus from 2.87 to 1.14 reduces the concrete strength with 5%-tripoli addition from 38.9 MPa to 21.8 MPa, and with its content of 10% from 36.3 MPa to 20.4 MPa. The dependence of heavy concrete strength after 7 and 28 days of hardening on the content of its components was determined by the method of mathematical planning of the experiment, it allows predicting the values of this indicator when varying the composition of the concrete mixture.
Improving crack resistance of concrete when using expanding cements
Authors: Samchenko S , Krivoborodov Yu 
Published: December 2019

Abstract
The possibility of enhancing the basic properties of concrete products by using a mixture of Portland cement and sulfoalumoferrite clinker as a binder is considered. It was established that upon hydration of the binder, aluminate and ferruginous ettringite are formed, which increase the strength properties of concrete during normal hardening and thermal and wet processing by increasing the strengthening structure. The main sign of hydration of sulfoalumoferrite clinker is the stability of ferrous ettringite, which ensures the compaction of the concrete structure. The dense structure of the structure of concrete, especially the contact zone, when using sulfated clinker, ensures the non-shrinkage of concrete and eliminates shrinkage deformations and, thereby, increases the crack resistance of concrete samples.
Interrelation of rigidness of triangular cross-sections under bar torsion with conformal radii relation
Authors: Korobko V I , Korobko A V , Lygina J E 
Published: December 2019

Abstract
The investigated problems of interrelation of the given geometrical rigidness of bars cross-sections of pure torsion with the geometrical characteristic of cross-sections – the relation of the internal conformal radius to the external conformal radius are covered in the article. Formulas for calculation of values of internal, external conformal radii and their relations for arbitrary, isosceles and rectangular triangles are given and the approximating functions for definition of these geometrical characteristics for triangles of any form are constructed. The graphic analysis of the obtained values shows that all variety of the relations of conformal radii presented graphically depending on one of the triangle corners falls into two subsets. One of them includes all variety of acute triangles, which is limited to isosceles acute triangles and rectangular triangles, and another one is limited with isosceles obtuse triangles and rectangular triangles. The graphic analysis of the whole variety of the known values of the given geometrical rigidness of triangular cross-sections at torsion, presented depending on one corner of a triangle, demonstrates that this geometrical characteristic is functionally connected with the relation of conformal radii; the corresponding approximating functions have linear character.
Experimental determination of yield in beam-to-column flange connections
Authors: Son M P 
Published: December 2019

AbstractThe paper describes a universal test bench, designed to conduct full-scale studies of the strength and stiffness of joints of building structures. The paper present the results of full-scale tests of the joints of beam flanged connections with columns in the elastic and elastoplastic stage with the determination of the dependence of their yield on the value of static loads. The study was conducted on 12 models with both one-sided joining of the beam to the column, and with two-sided, for which the flange thickness, resistance class and the controlled tension of the bolts, loading scheme were varied. The experiments were carried out according to a multifactorial plan until the destruction of the models. According to test results, 4 characteristic trilinear diagrams were obtained for dependence of the angles of rotation versus bending moments. The obtained results can be used in the design of flange connections and during the verification of their design models.
Time analysis of dynamic response of spatial frame building under action of seismic forces
Authors: Artemyeva L M , Potapov A N , Razzhivina A V 
Published: December 2019

Abstract
An analytical approach to the calculation of the spatial framework for the action of seismic forces is considered. This approach is an extension of the previously proposed time analysis method and used to determine the dynamic response of a dissipative structure modeled by a discrete computational scheme. Mathematical models of oscillations are given: the differential equation of motion of a dissipative system, the matrix characteristic equation with a quadratic input parameter and the fundamental matrix that carries out the relation between the differential and characteristic equations. Accounting for internal friction is carried out in accordance with the model of non-proportional damping. The structure of the vector of seismic forces generated by earthquake accelerogram data is shown. The kinematic and force characteristics of the system are determined by the equations of the seismic reaction of the framework at any time. The parameters of the calculated dynamic model (stiffness, damping and mass matrices’ elements) are constant on the entire interval during the calculation of elastic seismic response. Dynamic reaction equations are constructed in an analytical form based on the Duhamel integral. An example is given of analyzing vibrations of a 3-storey spatial framework under the action of a seismic load.
Geometric rigidity of torsion of thin-walled pipes: theory and experiment
Authors: Korobko A V , Kalashnikova N G , Tyurin V O 
Published: December 2019

Abstract
Thin-walled rods as structural elements of buildings, structures and machines that absorb torsion deformations are widely used in construction and engineering. Development of analytical methods for solving the problem of torsion of rods of non-circular cross section is one of the most important modern problems of construction mechanics. When solving torsion problems, the geometric rigidity of the section Ik
is primarily determined. The analysis of the considered literature sources showed that the study of the problem in question using the isoperimetric properties of cross-sections of rods is very effective. In the present paper, for thin-walled pipes with an arbitrary convex contour and constant wall thickness, the authors obtain calculation formulae that associate the reduced geometric rigidity of the cross-sections of the pipes Ik
with their form factor. It allows formulating the isoperimetric properties of the parameter under study depending on the shape of the pipe sections, and using geometric methods to determine the geometric rigidity of the cross-sections of pipes of arbitrary shape and a convex contour. The article also contains the results of experimental studies of triangular pipes confirming this isoperimetric relationship of the reduced geometric rigidity of pipes with the form factor.
Fatigue behavior of concrete in cyclic low-temperature impacts
Authors: Pinus B I , Kalashnikov M P 
Published: December 2019

Abstract
Wear and tear of concrete and reinforced concrete structures in harsh climatic conditions is analyzed as a fatigue process with various cumulative failures. For the criteria of their prediction, it is proposed to use dynamic models containing the kinetics of changes of informative and sensitive indicators of the constructive properties of concrete during cyclical freezing and thawing (CFT). An experimental-analytical generalization of the measurement of the following indicators is presented: strength, components of deformations, cracking, and the energy potential of concrete destruction during the exhaustion of its frost resistance. It is proposed, as a first approximation permissible under the conditions of the onset of fatigue parametric failures, to take the level of external temperature and humidity effects equivalent to (ultimately) 85 ÷ 90% of the frost resistance mark.
On possibility of local suppression of natural vibrations of elastic structures under shock effects
Authors: Sobolev V I , Zenkov E V 
Published: December 2019

Abstract
Manifestations of shock effects in the form of subsequent natural oscillations of structures for various purposes can be different in intensity, in directions of oscillatory processes (forms of natural oscillations) and in frequencies involved in oscillatory processes. At the same time, the tasks of suppressing or reducing the intensity of oscillations in certain specified directions have obvious relevance. Suppression of forced stationary oscillations in certain specified directions (obtaining zero amplitudes of oscillations in these directions) is possible by forming dynamic quenching effects implemented as the systems that satisfy a number of formalized requirements for the design parameters of such systems. In earlier papers of the authors it was shown, that the realization of such effects in the processes of natural oscillations is associated with the formation of conditions for the multiplicity of natural oscillations of elastic systems. In the proposed paper the conditions for the formation of the multiplicity of natural frequencies of multiply connected finite-dimensional systems of small dimension are considered, reflecting the specific manifestation of the multiplicity of natural oscillation frequencies of finite-dimensional dynamic systems of arbitrary dimension, the properties of such systems are applied to the suppression of natural oscillations in specified directions.
Energy efficient building for arctic regions
Authors: Inzhutov I S , Zhadanov V I , Melnikov P P 
Published: December 2019

Abstract
The relevance of this topic is stipulated by the sharp changes in climate in the Arctic region, characterized by such factors as increased winds and blizzards, the impact of the stone particles from the quarries near industrial centers, low temperatures, temperature rise, decrease in the area and thickness of ice, melting of the Greenland ice sheet. In 2007-2008, satellite observations showed that its area reached the minimum for 30 years of observations, the next minimum was registered in 2012. In many existing Northern cities and towns, a serious problem with the functioning of housing and communal services is beginning to emerge: emergency and dilapidated housing exceeds the average for Russia. A significant number of standard projects, not adapted to the extremely harsh Northern conditions, requires frequent repairs, excessive heat and energy, which leads to a huge expenditure of funds. These factors determine the need to design new types of buildings in high-latitude regions
Supporting structures of machine-building enterprises of 1920-1930
Authors: Buzalo N A , Kozhihov A G , Tsaritova N G 
Published: December 2019

Abstract
The article provides an analysis of the design solutions of industrial buildings of the engineering industry, that were built in 1920-1930. This period is characterized by the use of monolithic and precast concrete elements as the supporting structures of the frames of industrial buildings, because of the need for super-efficient use of steel. Low-carbon steel of low grades was used as reinforcement. Space-planning and constructive solutions of buildings of this period are not peculiar to later periods of construction. The purpose of research is to identify and describe the characteristic features of the frameworks, its inherent defects and damage of the supporting elements, and ways to eliminate them. As a rule, the considered buildings are characterized by increased spatial rigidity and stability, provided by the rigid coupling of columns with foundations, monolithic transverse elements and longitudinal crossbars. This explains the safety of supporting structures during long periods of operation, low sensitivity to the sediments of the supports during deformations of the soil base. Enclosing structures, self-supporting walls on almost all the objects surveyed have become inoperable. To continue the exploitation of such buildings, almost complete replacement of envelopes, repair and strengthening of local damage of supporting reinforced structures is required.
Modelling and numerical solution of problems of structural mechanics with unilateral constraints and friction
Authors: Lukashevich A A , Lukashevich N K 
Published: December 2019

Abstract
The article deals with the problems of calculation of elastically deformable systems with unilateral constraints and Coulomb friction. For the numerical solution of the problem, the finite element method is used, the contact interaction is modeled by means of the contact finite elements (CFE) of the frame-rod type. The basic relations and statements of static and dynamic contact problems for the interacting elastic bodies are given. To comply with the limitations under the conditions of ultimate friction-sliding, the method of compensating loads is applied. On the basis of the proposed discrete contact model and step-by-step loading schemes, the numerical algorithms are developed, which allows calculating structures with unilateral constraints and Coulomb friction, both under static and dynamic loads, as well as taking into account the different contact conditions that approximate the calculation scheme to the real operating conditions of a structure or construction. With the help of the proposed approach, numerical solutions of the problem of contact of the structure with the base under dynamic load are obtained and analyzed.
Behavior of compressed concrete in a glass fiber-reinforced shell
Authors: Krishan A L , Chernysova E P , Astafyeva M A 
Published: December 2019

Abstract
The paper presents a theoretical study of the structural resistance of short compressed concrete elements in a glass-fiber reinforced shell. The methodology is based on a nonlinear strain model of how this element reacts to incremental loading. What makes computing such structures difficult is the need to account for the continuously changing lateral shell pressure on the concrete core. Lateral pressure keeps increasing due to changes in the concrete-core and glass fiber-reinforced shell lateral-strain coefficients, causing greater stress in the material. This paper is the for to propose formulas to account for such changes and measure lateral pressure for any load on such a structure. It also outlines practical guidelines on computing the strength of short compressed concrete elements in a glass fiber-reinforced shell.
Research on problems of panel buildings
Authors: Mavlyuberdinov A R , Mukminov R N 
Published: December 2019

Abstract
The purpose of the study is to identify and reveal the main problems arising from the operation of panel buildings, to determine the location of the leakage of joints in panel buildings and to analyze the economic effect of a thermal imaging survey with subsequent repair. The main results of the research consist in analyzing the types of joints of large-panel buildings and their features as well as in conducting the thermal imaging survey of interpanel joints for heat loss and identifying the most problematic areas, according to the results of which heat loss is formed through the vertical and horizontal joints between the panels, as well as at the junction points of the windows. According to the results, the economic effect of the thermal imaging survey shows that the additional costs of paying for heat before overhaul due to the deterioration of the thermal protection quality are many times greater than the cost of the thermal imaging survey, taking into account the additional costs of eliminating thermal protection defects.
Numerical modelling of the reinforced concrete beam shear failure
Authors: Budarin A , Alekhin V , Avdonina L 
Published: December 2019

Abstract
Shear failure of reinforced concrete members is a complex process, which depends on a huge number of different factors. It is less investigated compared to other types of failure. Modern numerical methods, including finite-element method, allow predicting complex behavior of different structures when loaded. This article deals with the detailed nonlinear analysis of the shear failure of the reinforced concrete beam, using Drucker-Prager yield criterion. The results generated based on the finite-element model, developed in ANSYS software, were compared to the results of a laboratory experiment. In addition, the main advantages and disadvantages of this approach were described.
Some aspects of construction industry development in 2018
Authors: Peshkov V V 
Published: December 2019

AbstractThe construction industry, despite the economic difficulties, has long been one of the most stable and dynamic sectors in the Russian economy. Being one of the main sectors of the economy of each country, the construction industry performs the main task - the introduction of new, reconstruction of old objects, both residential and commercial purpose. The development of the construction industry is among the most important tasks of the government of all countries. Analysis of the economic situation in the construction industry can identify problems and identify areas of development of the construction industry. The article describes the indicators reflecting the efficiency of the industry in Russia and in the Irkutsk region. The construction industry is suffering from a skills shortage, slim margins and low productivity, but help is at hand in the form of new technologies and innovative materials. Measures aimed at supporting the development of the construction industry by minimizing the existing problem areas are proposed. The author think the construction industry should not be overlooked in this day and age. It is necessary to develop a “road map” for the development of the construction industry in the coming years, which will determine the priorities and main directions of the state regional policy in the construction sector, tasks, activities and development targets.
Determination of design layer of rainfall for design of treatment facilities of surface runoff
Authors: Palagin E D , Gridneva M A , Bykova P G 
Published: December 2019

Abstract
The article assesses the influence of the initial data and the duration of observations on the calculated value of the sediment layer, which determines the performance of treatment facilities of surface runoff. At design of these constructions drain volume from a settlement rain is found. The error introduced by the grouping of initial data depending on the accepted gradation of intervals is determined. The daily layer of precipitation from low-intensity frequent rains with a period of a single excess of the calculated intensity of 0.05-0.1 years was determined (for the conditions of Samara). Recommendations on the choice of initial data in the design are given.
Study of aerodynamics of stream flow in server rooms using numerical modeling
Authors: Trubitsyna G N , Surovtsov M M , Indykov V S 
Published: December 2019

Abstract
This paper analyzes various schemes of air exchange in server rooms. Top-down and down-top vertical cooling schemes for small server rooms using local AC systems were analyzed. Numerical models were developed for the study of heat and mass transfer and server aerodynamics, which make it possible to evaluate the cooling efficiency of electronic equipment when placed in an arbitrary configuration. To study the thermal and velocity fields, numerical simulation of the stream flow processes was performed using the FlowVision software. This paper shows the advantage of the selected air-conditioning scheme compared to the existing ventilation system. Modeling results may be used for designing small server rooms.
Rotunda church in Russia as typological phenomenon
Authors: Tereshina O B 
Published: December 2019

Abstract
The article describes results of a complex research, in the course of which the main stages of origination and formation of a rotunda church as a rare type in the history of the world’s and Russian architecture have been determined. The main groups of rotunda churches in the world architecture (7 types) and Russian architecture (9 types) have been identified together with criteria of their classification and typological characteristics, the chronology frames of formation of certain types. Space-planning and compositional decisions in designs of rotunda churches have been analyzed based on their types in the context of typology developed by the author. The types of rotunda churches and individual monuments of rotunda church architecture from the world architecture history, which served as a source of inspiration for architects in Russia, are considered. Features of Russian rotunda churches connected with the Orthodox traditions and national traditions of church architecture were identified. The examples of rotunda churches around the world, constructed within the multi-age period between the 6th century BC till the 19th century, and of Russian rotunda churches constructed within a short period from the end of the 17th century and till the middle of the 19th century, are made.
Approaches to design of navigation systems in public institutions
Authors: Surina L 
Published: December 2019

Abstract
The article considers specificities of design of navigation systems in public buildings and institutions, transformation of verbal information into a sign, symbol, pictogram, as well as simulation of versatile structures of navigation system carriers and their experimental application. Comparative analysis of principles of designing navigation systems in public buildings and institutions, intended to systematize a big volume of information transformed into a symbol, sign or pictogram, which favors for its quick perception, is carried out. The article considers the main principles of design of navigation systems. The research relevance is determined by the necessity to create versatile navigation systems for the improvement of communication in various public institutions.
Fractal properties of settlement system as factor of its sustainability: Ural in the 18th–20th centuries
Authors: Bystrova T J 
Published: December 2019

Abstract
The thoughts by N. Salingaros on sustainable design, translated and introduced into scientific discourse by the author of the paper, served as a basis for primary analysis of the layout of a small industrial town and the settlement system of the industrial part of the Urals. Invariable features of the town layout have been reconstructed based on the materials by W. de Gennin and modern historical and cultural studies. The paper shows the elements of fractality and self-similarity in the layout of small industrial towns and in the Ural settlement system, which correspond to the parameters established by N. Salingaros. A conclusion is made about sustainability as an additional internal resource of the settlement system in the region.