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2019

Archives Journal Construction Materials and Products Vol. 2

FOR THE STUDY OF PECULIARITIES OF STRUCTURE FORMATION OF COMPOSITE BINDERS FOR NON-AUTOCLAVED AERATED CONCRETE

https://doi.org/10.34031/2618-7183-2019-2-3-41-47
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 41-47 p.
Abstract
The basis of the modern market of cellular concrete is autoclaved gas silicate. At the same time, non-autoclaved aerated concrete is largely a more technological material, allowing the variation of its properties within a wide range, having a potentially wider field of application, less costly in the organization of production, which is of great importance for small and medium-sized businesses. The main problem of non-autoclaved aerated concrete is a higher cost of raw materials compared to silicate, and 20...30% lower strength performance. The proposed solution to this problem is the development of special composite binders with a limited content of clinker and mineral additives of various genetic types, taking into account the peculiarities of the two-stage structure formation of the material – gas porization and the formation of the microstructure of the stone. The article deals with some aspects of the interaction in the system “mineral additive – gypsum – by-products of the gas release reaction” in terms of the effect on the viscosity of the swelling mass and the strength of the stone at different times of hardening. Recommendations are given on the preferred compositions of composite binders and dosages of gypsum in the molding mixture when producing a material with an average density in the range of 500...700 kg/m3.
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NUMERICAL CALCULATION OF STRESS-STRAIN STATE OF EARTH DAM UNDER BASIC LOADS WITH ACCOUNT OF INHOMOGENEOUS FOUNDATION

https://doi.org/10.34031/2618-7183-2019-2-3-48-57
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 48-57 p.
Abstract
Design, construction and operation of earth hydrotechnical structures located in seismic regions require a continuous improvement of computational methods for calculating various loads (static and dynamic ones). On the basis of the developed methodology and the complex of applied programs, an earth dam (Tupolang HPP) is calculated for the basic loads (gravity forces, hydrostatics) taking into account the design features and the actual physical and mechanical characteristics of soil both at the structure and at its earth foundation ( the height of the structure is 165m).The problem is solved in a plane elastic statement by the numerical finite element method. As the result of the calculation the isolines were obtained of equal displacements (horizontal and vertical), stresses (normal, tangential, principal) over the area occupied by the structure and its inhomogeneous foundation. A number of physical conclusions were made regarding the construction of important structures on an inhomogeneous earth foundation.
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THE USE OF COMPOSITE MATERIALS IN RECONSTRUCTION OF FLOORS OF INDUSTRIAL BUILDINGS

https://doi.org/10.34031/2618-7183-2019-2-3-58-64
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 58-64 p.
Abstract
The article discusses the relevance of the use of composite materials in the reconstruction of exposed to heavy loads of concrete and reinforced concrete floors of industrial buildings. It is noted that at the present stage of development of the construction industry special attention is paid to the use of steel fibreconcrete, as this material allows with minimal material and labor costs to carry out work on the reconstruction of industrial floors. The novelty of this study is the use as an adhesive between the existing floor, which is to be restored and strengthened, and the newly laid steel-fiber concrete layer of polymer-bitumen composite material with the addition of cement and graphite powder, previously obtained by the authors experimentally. This material with the required thickness is also a structural layer for leveling the surface of the lower layer, reducing friction under the sole of the upper steel-fiber concrete layer and the existing floor. The paper presents the technology of work in the reconstruction. The composition of the steel-fiber concrete layer is adopted on the basis of studies by other authors. Despite the fact that the experiments proved the solidity and strength of the reconstruction of the floor by the developed technology, the article notes that the final characteristics of the proposed floor design and technology can be identified only during operation, which can be the basis for further research on optimizing the thickness of the layers proposed for use of composite materials. For the evaluation of economic efficiency of application of these composite materials in the reconstruction of the concrete floors in the course of the experiment, there are revealed some figures for labor and material costs.
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DIRECTED REGULATION OF PROPERTIES OF ASPHALT CONCRETE BY NANOCARBON OBJECTS

https://doi.org/10.34031/2618-7183-2019-2-3-65-71
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 65-71 p.
Abstract
Directed regulation of asphalt concrete properties is an important condition for obtaining a durable material that minimizes operating costs. One of such perspective directions is modification of building compositions by nanoscale objects. The method of modification of mineral powder from dolomite by carbon nanotubes is considered in the work, and results of tests of asphalt concrete on its basis are given. It is shown that the use of nanomodified dispersed dolomite in the technology of preparation of asphalt concrete mixture on the surface of the grains of mineral material forms a strong, high-temperature resistant layer of structured bitumen. The increase in the dynamic viscosity of bitumen and the complex shear modulus under the influence of CNT contributes to the change in the yield strength of asphalt concrete above the maximum shear stresses, which leads to a slight accumulation of residual plastic deformations in the plate in the study of the resistance to ruts. Thus, modification of bitumen and asphalt concrete with nanoscale additives can be an effective tool in the fight against plastic deformations such as shifts, surges and rutting in hot climates, for example, in Jordan.
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THE CONCENTRATION OF THERMAL STRESSES IN METAL MATERIALS AND CONSTRUCTION UNDER LOCAL HEATING

https://doi.org/10.34031/2618-7183-2019-2-3-72-77
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 72-77 p.
Abstract
Significant thermal stresses arising in thin-walled metal materials and structures loaded with tensile stresses can lead either to their complete destruction or to the appearance of discontinuity zones in them. The equa-tions for calculation of temperature stresses in flat thin-walled structures at their localized thermal heating caused by the action of concentrated energy flows are analyzed. As an example, a thin-walled stretched plate subjected to strong local heating in a circular spot is considered. The developed model takes into account the change of elastic characteristics under strong local heating and the change in the thickness of the material in the heating spot. As an example, the diagram of the distribution of tangential stresses for a stretched plate in the area of a circular heating spot is given. Thus, the results of the study show that there is a rupture and concentration of stresses along the contour of the heating spot from the cold zone.
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ENVIRONMENTAL MONITORING OF ECOLOGICAL SAFETY IN AREAS OF CONSTRUCTION, RECONSTRUCTION AND OPERATION OF OBJECTS

https://doi.org/10.34031/2618-7183-2019-2-3-78-84
 78-84 p.
Abstract
Environmental monitoring of construction production should use modern scientific and technical method of physical, chemical and biological control for periodic or continuous monitoring and measurement of factors associated with chemical pollutants and physical and biological pollution on the spot, and for the correct assessment of environmental quality.
For a construction project, all stages of construction production need environmental monitoring due to different monitoring purposes.
During the entire construction period, environmental monitoring can accurately, timely, comprehensively reflect the impact of construction work on the site and the environment and provide a scientific basis for environmental management. Continuous monitoring provides real-time, up-to-date results to help environmental management professionals understand environmental quality in a site and be able to respond in a timely manner.
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FEATURES OF USING BUILDING MATERIALS IN RESTORATION OF ARCHITECTURAL AND TOWN-PLANNING HERITAGE

https://doi.org/10.34031/2618-7183-2019-2-3-85-89
 85-89 p.
Abstract
The article is devoted to the study of the principles of the use of building materials in the restoration of monuments of architectural and urban heritage. The basic properties of materials, classification and specificity of their application are indicated. As a result of the analysis, the most important role of the material in the formation of the architectural image of the object is justified. It is concluded that the material should be considered not only in the context of technical parameters, but also in terms of architectural and artistic characteristics. The attention is focused on the understanding of the authenticity of the object and on the operational properties of materials for decoration. It is noted that the choice of material should be based on the previous stage of material research, as a segment of a detailed survey of the technical condition of the structure.
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ARCHITECTURE AND DESIGN SUPPORT OF IMPLEMENTATION OF THE SOCIO-ECONOMIC DEVELOPMENT STRATEGY OF THE CITY DISTRICT

https://doi.org/10.34031/2618-7183-2019-2-3-90-95
 90-95 p.
Abstract
The strategies of long-term development of regions, urban and rural districts are developed taking into account the general characteristics of the achieved level of socio-economic development, they are coordinated, evaluated, clarified with the use of social surveys. In the implementation of relevant policies enhancing the investment attractiveness of the area and attracting and retaining the personnel potential, the development of scientific-industrial complexes, tourism cluster. Implementation of the Strategy of socio-economic development of the city district of Togliatti, Samara region of the Russian Federation until 2030 is ensured with the use of technology architectural design aimed at the development of the cultural environment, improvement of public areas, renovation and improvement of cultural heritage objects, the development of the information environment. Examples of actual design decisions in the listed directions, in relation to the allocated objects of the city district of Togliatti are given.
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MODERN TENDENCIES AND PROSPECTS OF DEVELOPMENT OF SPATIAL AND FUNCTIONAL DESIGN CHARACTERISTICS OF TYPICAL BUILDINGS IN RUSSIA AND ABROAD

https://doi.org/10.34031/2618-7183-2019-2-3-96-102
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 96-102 p.
Abstract
The article presents modern foreign and domestic trends in architectural-spatial and functional-planning solutions for economy-class apartments and the prospects for the development of typical design in Russia. It is becoming increasingly clear that mass construction in Russia does not require significant development since Soviet times, when construction should be carried out for the sole purpose of providing citizens with affordable housing with minimally acceptable parameters in shortened terms. The most significant differences of modern Russian housing from foreign is the reduced range of functional premises and smaller areas. The modern consumer has other ideas about comfortable living. In addition, modern domestic and foreign experts in the field of architecture and construction confirm the need for an innovative approach to the design of urban buildings. It is assumed, that the use of existing trends in the housing project will significantly increase the level of comfort of apartments without a significant increase in the cost per square meter. Comparison of domestic and foreign experience in the construction of residential buildings brought a number of common features and significant differences, which are analyzed in the article. They include: the tendency to individual design, the tendency to a change in living space, the tendency of vertical functional zoning, the tendency of zoning, the trend of expanding the functional-planning composition of the standard layout of ancillary rooms, sanitary and household zones.
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IMPROVING THE EFFICIENCY OF FIBRE CONCRETE PRODUCTION

https://doi.org/10.34031/2618-7183-2019-2-2-4-9
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 4-9 p.
Abstract
Fiber concrete is one of the types of effective building materials that ensure the operational reliability of structures due to a set of unique properties. However, the maximum physicomechanical characteristics of this type of products are achieved only if the fiber is evenly distributed in the concrete matrix and the optimum ratio of raw materials is reached. In this connection, the aim of the work was to increase the production efficiency of fiber-reinforced concrete by optimizing the formulation and technological parameters of its manufacture. The optimal method of introducing the fiber into the concrete mix and the type of superplasticizer were previously determined, which allowed ensuring the maximum physicomechanical characteristics of the products. Optimization of prescription parameters was carried out using the method of mathematical planning of the experiment, where the amount of cement, superplasticizer and basalt fiber were varied. After processing the results, the dependences of the compressive strength on variable factors were obtained, which would allow to select the optimal dosages of raw materials for given mechanical characteristics of the products.
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