bluuebunny/crossref_metadata_2025_split huggingface dataset:
Load carrying ability and optimal characteristics of the roof slab made of profiled sheeting
Authors: Nizameev Vasil , Basharov Fanzil , Nizameeva Luiza 
Published: August 2020

Abstract
The subject of the study is the roof slabs, made of profiled sheetings, supported by bottom truss systems. The profiled sheet, being the upper belt of these structures, experiences longitudinal-transverse bending under the distributed transverse load and a longitudinal eccentric compressive force. Analytical and numerical studies determined the stress-strain state of the profiled sheeting. The dependences of the limiting value of the distributed load on the compressive longitudinal force and the eccentricity of its application are revealed. A technique for optimizing the design parameters of roof slabs have been developed. The studied roof slabs made of profiled sheeting, supported by a truss system, have a rather complicated design with many parameters, on which the performance criteria depend. Studies of the ties between these parameters are quite laborious. Therefore, it is not possible to solve the problems of optimizing these structures by known analytical and numerical methods. To find the rational parameters of the studied slabs, we used the method of phased numerical experiments using simplex optimization. Using this technique, the optimal structural parameters of the slabs with spans of 6-12 m were determined for a given efficiency criterion.
Experimental and theoretical studies of plug joints reinforced concrete columns under transverse force
Authors: Abdrahimova Natalya 
Published: August 2020

Abstract
The analysis of scientific and technical literature indicates the responsibility of joints of prefabricated elements of buildings for structural safety and reliability under the influence of static loads. According to numerous publications by domestic and foreign authors, in frame buildings, the first signs of destruction appear at the joints of elements due to stress concentration. It is possible that at the operation stage the joints will not meet the requirements of reliability and durability due to a number of reasons: the effect of non-design loads, the presence of defects in the manufacture of the joint and installation (non-design reinforcement, cracks in concrete, incomplete filling of joints, etc.). Therefore, ensuring the structural safety of the building and operational suitability by strengthening joints at minimum cost is an urgent task.
Method of calculating the shear stiffness of the flooring under the action of horizontal loads
Authors: Gimazetdinov Aivaz , Kayumov Rashit , Shmelev Gennady , Khaidarov Lenar , Antonov Anatoly 
Published: August 2020

Abstract
This article deals with the issue of calculating combined plywood-metal flooring as a horizontal disk of stiffness, taking into account the structural non-linearity. An analytically obtained method calculating the shear stiffness of the flooring under the action of horizontal loads is proposed.
The task was to derive a three-line correlation - relationship for the fictitious connection operation, based on the constructively nonlinear operation of the flooring. Based on the proposed analytical method of calculating the shear stiffness of the flooring under the influence of horizontal loads, the work of the flooring is modeled as part of the design scheme shown in the figure. The resulting diagram of fictitious relationships was introduced as a characteristic of nonlinear work. In manual calculation in the derivation of the analytical formulas, the compound was considered as a pure hinge. We can conclude that the proposed analytical method of calculating the shear stiffness of the flooring when it is working on a horizontal load, taking into account the structural non-linearity.
Experimental determination of dynamic characteristics and analysis of acceleration of vibrations of pedestrian bridges
Authors: Gimazetdinov Aivaz , Kayumov Rashit , Shmelev Gennady , Khaidarov Lenar , Antonov Anatoly 
Published: August 2020

Abstract
This article discusses the design of pedestrian bridges. When designing pedestrian bridges, engineers are guided mainly by the static characteristics of the types of spans under consideration. If you want to build a load-bearing beam structure of a large span, you cannot lose sight of their relatively large mass and low stiffness due to the length of the bridge. These factors lead to a low natural frequency close to the frequency of pedestrian load, in the form of people passing through this structure, which, in turn, act as recipients of vibrations. The structure is a metal span restructure with two I-beam main beams with a solid sloping wall, an orthotropic plate of the passer-by part below, a calculated width of 44.0 m, a total length of 44.6 m and a pedestrian dimension of 3.25 m. In the course of dynamic tests of the pedestrian bridge span, experimental values of the natural vertical vibration frequencies were determined, followed by the determination of the attenuation decrement. The natural oscillation frequency was 2.0 Hz, which corresponds to a period of 0.5 s oscillation.
About concrete and reinforced concrete corrosion
Authors: Mirsayapov Ilshat , Yakupov Samat , Hassoun Majd 
Published: August 2020

Abstract
This review article provides general information about reinforced concrete corrosion and types of corrosion. The most dangerous consequence of corrosion processes in reinforced concrete is a decrease in the load-bearing capacity of the structure. Corrosion of reinforcing steel is one of the most common damages to reinforced concrete structures. The most dangerous type of rebar corrosion is chloride corrosion, since at a certain concentration of chlorides, the concrete immediately loses its protective properties in relation to the rebar, the corrosion develops locally and deep into the rod, leading to significant losses of its cross-section, often without visible damage to the concrete surface. Types of corrosion: physical corrosion, chemical corrosion, leaching corrosion, magnesian corrosion, carbon dioxide corrosion, sulphate corrosion, hydrogen sulfide corrosion, biological corrosion, electrochemical and electroosmotic corrosion, the destruction of cement stone.
The article provides an overview of the mechanism of reinforcement corrosion, its initiation, progress and factors that expedite the process of reinforcement corrosion. Once the reinforcement corrosion is initiated, it shortens the service life of the structures by cracks initiation, propagation and subsequently spalling of the cover concrete due to expansion of corrosion steel. Corrosion of the embedded reinforcing steel is the most frequent cause for degradation.
Features of information modeling of cultural heritage objects
Authors: Badenko Vladimir , Fedotov Alexander , Zotov Dmitry , Lytkin Sergey , Lipatova Alexandra , Volgin Dmitry 
Published: August 2020

Abstract
This paper focuses on features of heritage objects information modeling and its integration with structural analysis under various types of impacts. We discuss different results of structural analysis based on finite element model (FEM) of the New Hermitage portico. Thanks to laser scanning technology it was possible to collect all the geometric features of this object and generate an adequate mathematical model based on the obtained data. The methodology of finite element model creation based on laser scanning and BIM technologies is proposed. Some interesting results of laser scanning survey and numerical modelling have been discussed. Deviations of the portico’s structural elements have been identified based on the use of laser scanning, BIM and FEA. It has been found out that the displacement of the upper parts of the columns relative to the lower ones in the direction of the facade wall is 4 cm. An intermediate HBIM of the portico (LOD 100) has been created inside Revit. Finite element model with default element size of 300 mm has been created using ANSYS. Directions for further research have been also determined.
Stress-strain state prediction for statically indeterminate system with accounting for malfunctioning of rod elements production
Authors: Efimov Oleg , Salimov Aidar 
Published: August 2020

Abstract
The use of pre-tension as a regulating mechanism in structures that are statically indeterminate rod systems usually implies the absence of initial forces and stresses. It is necessary to take into account its initial stresses from probabilistic positions and adjust the pre-tension parameters accordingly. The laws of distribution of deviations of rod elements or shipment-sized sets of details from nominal sizes and shapes are usually known. The technique of determination of reliable enough value of initial effort in the certain connection of interest of the statically indeterminate system (SIS) because of deviations of rod elements or shipment-sized sets of details from their nominal sizes and forms is presented. Thus, deviations of both rod elements and dispatch brands from the nominal sizes and forms are known to be random variables with symmetric laws of distribution. The task is solved in linear statement with result of research giving the opportunity to determine the value of initial effort using just one static design calculation.
Settlement of the base of clay soil under regime weighting
Authors: Mirsayapov Ilizar T. , Sabirzyanov Danil D. 
Published: August 2020

Abstract
The aim of the article is the development of the theory of strength and deformation of clay soils under conditions of triaxial compression under combined alternating long-term static and cyclic loading. As a result of the research, new experimental data were obtained on the peculiarities of the stress-strain state of clay soils under triaxial compression under combined alternating long-term static and cyclic loading, as well as the development of base sediments of foundation models in laboratory conditions. The significance of the results obtained for the construction industry lies in the fact that experimental studies of determining the changes in the strength and deformability of clay soils under combined alternating long-term static and cyclic loading are necessary for the modernization of engineering methods for calculating sediments and the bearing capacity of foundations.
The assessment of critical vibration values of the construction based on the application of the bifurcation approach in automated geotechnical control systems
Authors: Dorofeev Nikolay , Grecheneva Anastasia , Romanov Roman , Pankina Ekaterina 
Published: August 2020

Abstract
The article deals with the description of the method of building construction stability assessment based on the bifurcation approach and vibration parameters for automated geotechnical control. The use of external vibrational geotechnical noise as a source of a sounding signal in automated systems of geotechnical monitoring is proposed and justified. The interrelation of the influence of vibrational factors on the stability parameters of structures is established and their numerical characteristics are given. A nonlinear model of the stability of the structure is given taking into account the impact of vibration factors. The dynamic behavior of structural elements of the structure with one degree of freedom was modeled, taking into account the load, and a bifurcation diagram was constructed. It is established that in the presence of technogenic vibrational noise, the mass of the upper floors of the building has a significantly greater effect on the stability parameters of the structure. The effectiveness of the proposed approach is proved by comparing the values obtained in the calculation of the mechanical stiffness of the structure according to the standard method using a dynamic coefficient.
Steel timber-concrete beams. Numerical and full-scale experiments
Authors: Zamaliev Farit 
Published: August 2020

Abstract
The first composite beams in the cross section of which concrete and wood were used, were patented at the end of the 19th century. In this article, technical solutions are analyzed based on works of the recent years. New beam designs have been developed. The Russian Federal Service for Intellectual Property (Rus. Rospatent) has issued patents to Kazan State University of Architecture and Engineering (KSUAE) for invention and utility model of new solutions of steel-concrete section beams. Analytical and experimental studies, the experience of using wood-concrete and wooden structures with reinforcement from different materials in the stretched area of the beam are studied. Based on their analysis, new solutions for steel-concrete beams were developed, in which bent steel profiles were used in the stretched zone of the beam, a research program was drawn up.
Numerical studies of steel-concrete beams and thickness variations of bent steel profiles, wall height, pitch, length and diameter of self-tapping screws were carried out.
Experimental studies were carried out using a beam model, the parameters of which are taken from the results of numerical studies. The methodology and test results of the beam are given. The test results are presented in the form of graphs of stresses, deformations, deflections. In conclusion, satisfactory convergence of the results of numerical and laboratory studies of the studied beams of composite section is noted.
Influence of the technological properties of cement-sand mortar on the quality of 3D printed products
Authors: Mukhametrakhimov Rustem , Lukmanova Liliya 
Published: August 2020

Abstract
The results of the influence of cement-sand mortar mobility on quality of hardened composites, made by 3D concrete printing (3DCP), are presented. Four formulations of cement-sand mortar mixes with mobility classes Pk 1, Pk 2, Pk 3, Pk 4 which corresponds to immersion depth of the reference cone of 3.3 cm, 6.5 cm, 8.7 cm, 12.0 cm, respectively, were prepared for testing. It has been established that regulatory framework regulating 3DCP test methods not sufficiently developed and requires further improvement. It was revealed 3D printing of cement-sand mortar mixes with mobility classes Pk 2-Pk 4 on researched 3D printer is possible, however, products have defects and damages. Mortar mobility has a significant impact on structure kinetics and geometric parameters deviation. The lower mobility class is, the higher structure kinetics of raw material mix is, which is due to the early formation of the crystallization structure of hardened composite. Cement-sand mortar with class mobility Pk 2 accepted for further research in the development of adapted raw mixes for 3DCP.
Optimization of the geometry and calculation of the normal vibrations of the dendrimer with amine terminal groups
Authors: Furer Victor 
Published: August 2020

Abstract
The structure of the first generation dendrimer Gi constructed from a hexafunctional cyclotriphosphazene core with six branches -O-C6H4-CH=N-N(CH3)-P(S)< and twelve 4-hydroxyphenethylamine end groups O-C6H4-(CH2)2-NH2 was studied. Structural optimization and analysis of normal vibrations were performed for the Gi dendrimer. The Gi dendrimer molecule has a convex lens structure with flat -O-C6H4-CH=N-N(CH3)-P(S)< fragments and a slightly nonplanar cyclotriphosphazene core. Full optimization shows that the conformation of terminal 4-hydroxyphenethylamine groups O-C6H4-(CH2)2-NH2 with dihedral angles C(13)-C(22)-C(23)-N(6) and C(22)-C(23)-N(6)-H(23): 63.7 and 46.8° is predominant. The flat and anisotropic form of the cyclotriphosphazene core determines the ability of dendrimers to pack with each other in the most likely disk-like form. The spatial distribution of electron density for the core and end groups allows estimating the magnitude of electrostatic interactions on the surface of the dendrimer in the guest-host complexes.
The effect of carbon nanotubes on the curing processes of epoxy-amine compositions
Authors: Yagund Eduard , Potapova Ludmila 
Published: August 2020

Abstract
The effects of the concentration and functionalization of carbon nanotubes on the degree of conversion of epoxy groups in epoxy-amine compositions based on ED-20 epoxy oligomer and the PEPA curing agent are studied. It has been shown that increasing the concentration of functionalized carbon nanotubes (CNT) from 0 to 0.5 % increases the degree of conversion of the epoxy groups during curing at a room temperature. Further increase in concentration CNT of up to 1 % does not effect on the reaction kinetics. For native CNT not established such a relationship. Explains such a pronounced effect on the f-CNT aminolysis reaction kinetics and ultimate degree of conversion of epoxy groups, apparently, the catalytic effect of oxygen-containing groups (hydroxyl, carboxyl, and others) grafted to the surface of CNTs and their direct involvement in the reaction. By optical microscopy showed that the size of the agglomerates of nanotubes were substantially higher in the native systems than in the system with the functionalized nanotubes. These results may be important for the development of creation of epoxy composites modified by nanoparticles.
Modification of clay raw materials to optimize slip casting
Authors: Bogdanov Andrey , Abdrakhmanova Lyaila 
Published: August 2020

Abstract
The effect of surface-active substances (surfactants) on the state of water in clay was studied based on the data of swelling and sedimentation of clay particles in aqueous suspensions. The features of the influence of three types of additives-technical lignosulfonate and hyperplasticizers manufactured by Arkema and Movecreate are considered. When surfactant solutions are introduced into the clay system, an increase in the wettability of clay particles is observed, which promotes the adsorption of surfactant molecules on the surface of the dispersed phase, which depends on the structure of clay minerals and their impurities. Surfactants simultaneously have a plasticizing and structuring effect on the clay mass, leading to intensification of drying in the initial stages and, consequently, to a decrease in shrinkage deformations. The most effective additive is lignosulfonate, the introduction of which in an amount of 0.01 % in a clay suspension increases the fluidity of the suspension, and the mobility of water decreases by more than 3 times than in the presence of hyperplasticizers. The best preservation of the suspension is also ensured in the presence of a plasticizer-lignosulfonate. The main difference in the action of polycarboxylates and lignosulfonate is to change the sedimentation rate of clay suspensions. Modification of clay loam by surfactants leads to improved drying properties, quantified in a decrease in sensitivity to drying.
Bitumen chemical modification by a thermoplastic polymer
Authors: Ayupov Damir , Khakimullin Yurii , Kazakulov Rauf 
Published: August 2020

Abstract
Oil road bitumen was modified by a copolymer of ethylene with vinyl acetate (EVA) and 3-glycidyloxypropyltrimethoxysilane (epoxysilane). These modifiers were simultaneously introduced into the BND 90/130 oil bitumen at a temperature of 165 °C. The components were mixed up during two hours with further isothermal holding at the same temperature during the required period. Epoxysilane crosslinks bitumen with EVA making it possible to obtain an immiscible bitumen polymer binder. The optimal content of EVA is 12 mph, epoxysilane -3 mph with a mixing time of 4 hours. The optimal bitumen polymer binder is characterized by the following properties: softening point of 66 °C, penetration at 25 °C = 50, penetration index of 2.15, brittleness temperature of -22 ° C. Separation is significantly reduced. NMR spectroscopy has revealed that the introduction of the binding agent to the bitumen-polymer binder does not create low-mobile structures. It allows forecasting the high binder stability during storage and transportation.
Modified roman cement
Authors: Nikolay Shelikhov , Ruslan Sagdiyev 
Published: August 2020

Abstract
The purpose of this research is to equip the roman cement with properties exceeding the properties of the known analogies.
Roman cement’s compositions modified by chemical and mineral additives have been developed and proposed. The mode of calcinations of carbonate and clay raw material with high MgO has been optimized. As a result, the durability of roman cement from 15 to 22 MPa has been received. Mineral additives like slag, zeolite breed and clay dust were chosen and used that rose the durability from 22 to 28 MPa. Plasticizers and hardening accelerators were chosen and used that allowed rising the durability up to 35 MPa relatively. A combination of complex additives have been proposed.
To optimize the mode of calcinations and to define a combination of complex additives the method of mathematical planning was used. The dependence of binder’s strength from the temperature, durability of calcinations, saturation rate, type and consistence of modified additives has been acquired.
Modified roman cement has the advantages if compared with known analogies and has the following features: strength 35MPa, normal consistency 30%, setting time is not earlier than 35 minutes, the end is not late than 420 minutes, softening rate is 0.98.
Modified roman cement can be successfully used to produce dry building mixtures (mortar’s strength 5,10, 15 MPA), low strength mortars (strength 5,7.5 MPa) and concret (strength 10, 15, 20, 25 MPa) and other building materials.
Structure of carbonate raw material and clay for the production of roman cement is recommended.
The application of sulfur-asphalt concrete with modifiers in the climatic conditions of Vietnam
Authors: Le Huu Tuan 
Published: August 2020

Abstract
The paper considers the influence of ambient temperature and other weather factors on the properties of traditional asphalt concrete in Vietnam. The advantages of sulfur-extended asphalt concrete with modifiers containing neutralizers for the emission of toxic gases are presented to increase the quality and life of roads and solve the environmental problem of using sulfur-extended asphalt concrete. For calculating the surface temperature of asphalt concrete from the ambient temperature, the method of Yu. N. Kovalev is used (Russia). The weather data for January and July 2015, taken from the hydrometeorological stations of the cities of the respective zones in Vietnam, are used for calculations. The paper presents an experimental setup for determining the intensity of toxic gases evolution and the effect of neutralizers. The widespread introduction in the practice of building progressive environmentally friendly sulfur-containing materials: sulfur-extended asphalt concrete with modifiers, containing toxic gases emission neutralizers, which have higher physical and mechanical properties (wear resistance, etc.) compared to traditional ones at less or equal cost, can open up opportunities to increase quality and lifetime of roads in Vietnam.
Vibration separation of bulk construction mixtures by measurement sizes on sieve classifiers
Authors: adiev Fail Akhm , Gizzyatov Renat , Nazipov Ilshat 
Published: August 2020

Abstract
The vibrational separation of bulk building mixes by size is studied using stochastic-based sieve classifiers. The system of stochastic differential equations is constructed to determine the linear density of particles on the surface of the classifier sieves. The linear density of particles on sieves is approximated by white noise, which allows the system of equations to be called stochastic. The solution of the system of stochastic differential equations with respect to the average value of a random process is determined. We construct an approximate solution for the distribution density and transition probabilities of a random process using the properties of the white noise. Knowing the density of the distribution of the number of particles on the surface of the classifier sieves determines all its characteristics of interest. The obtained solutions allow us to calculate the extraction coefficient and evaluate the efficiency of separation.