Vol. 2 Issue 4

Archives Journal Construction Materials and Products 2019

THEORETICAL ASPECTS OF DEVELOPMENT OF COMPOSITE NANOSTRUCTURED GYPSUM BINDER CHARACTERIZED BY INCREASED HEAT RESISTANCE

https://doi.org/10.34031/2618-7183-2019-2-4-5-13
Abstract
There are a lot of different types of binders for construction purpose, a strong interest is focused on free-of-cement binders of new generation, which are characterized by unique and/or improved performance proper-ties. Among them there is composite nanostructured gypsum binder (CNGB) as a quite new binding system. In the framework of this study the hypothesis of synergetic effect in hardened binding system was proposed and approved. The hypothesis is realized when interaction of two binding systems with different structure formation mechanism such as followings: polymerization-polycondensation and hydration. A number of experiments were carried out and the results were obtained, which demonstrate a resistance of CNGB under high-temperature effect (up to 1000ºC) vs. ordinary gypsum binder. It was determined that a heat-resistance of CNGB is associated with joint crystallization of sulphate-based component (gypsum binder) and highly-reactive silica-based component (in nanostructured binder). Normally, nanostructuted binder is stable under high-temperature exposure. The indicator of synergetic effect is formation of new crystalline phase – hydroxyellestadite Ca5(SiO4)3(SO4)3(OH)2. This phase has unit cell size which is stable under temperature gradient. This characteristic allows saving structure framework in CNGB under high temperature.
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FIBER CONCRETE FOR 3-D ADDITIVE TECHNOLOGIES

https://doi.org/10.34031/2618-7183-2019-2-4-14-20
Abstract
Fine-grained fiber concrete used in 3D printing is significantly different from conventional heavy concrete, which is determined by the increased consumption of cement, low water-cement ratio and the absence of large aggregates. The largest grain size of fine aggregate is selected taking into account the thickness of the section, the frequency and type of reinforcement, as well as the method of concrete placement. Despite the fact that the tensile strength of concrete on fine sand is more than 1.5 times higher than the strength of concrete on coarse sand, while there is a decrease in compressive strength. Due to the peculiarities of the technology of concrete manufacturing for layering, the use of coarse sands is impractical, and therefore it was decided to use quartz sand with a particle size module of 1.12 as a filler.
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THE FORMATION OF THE HEAT-INSULATING PROTECTING STRUCTURES OF DOME BUILDINGS TO THE FAR NORTH

https://doi.org/10.34031/2618-7183-2019-2-4-21-26
Abstract
The regions of the Far North are of great importance in the economic development of the Russian Federation. The harsh climatic conditions of the Arctic predetermine the requirements for residential buildings, in par-ticular to ensure the thermal insulation properties of the enclosing structures of prefabricated buildings for living workers working in shifts. In this paper the calculation of the normalized values of thermal resistance of the protecting designs is made, the design and structure of walls and overlappings of collapsible structures is developed. To ensure the required thermal resistance at a minimum thickness of structural elements, it is proposed to apply liquid thermal insulation on the inner surface of the walls.
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DEFORMATION OF THE PACKING ELEMENT WHEN THE DIFFERENT PRESSURE IN THE BOREHOLE

https://doi.org/10.34031/2618-7183-2019-2-4-27-38
Abstract
A method for calculating the stress-deformed condition of the packing element shells reinforced with a sys-tem of metal tapes is proposed. The whole process of deformation of the shell under the influence of internal overpressure is conventionally divided into four stages. For each stage, the scheme of deformation of the shell is considered and the solution of the problem is given on the basis of the nonlinear theory of elasticity and the theory of soft shells. All stages of shell deformation considered in this paper are illustrated by the calculation scheme. An example of shell calculation with specified characteristics and deformation conditions is given.
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APPLICATION OF ACTIVE AND PASSIVE THERMAL CONTROL IN DEFECTOSCOPY OF CONSTRUCTION MATERIALS AND PRODUCTS, FILLER STRUCTURES OF BUILDINGS AND CONSTRUCTIONS

https://doi.org/10.34031/2618-7183-2019-2-4-39-44
Abstract
One of the perspective and modern methods of nondestructive testing – thermal control is considered. The possibilities and advantages of thermal control in the identification of defects in various building materials and products, enclosing structures of buildings and structures are given. The short characteristics of the main defects of building materials and products, buildings and structures are proposed. The basic principles of identification of hidden (invisible) and obvious (visible) defects are briefly considered and practical results of construction flaw detection of objects for various purposes with the use of thermal imaging equipment are presented. On the example of a fragment of the enclosing building structure of piece building products in the form of ceramic bricks with artificially created technical defects in the process of qualitative analysis of thermograms zone of thermal temperature anomalies (method of active thermal control) are localized. For some enclosing structures of buildings and structures based on the results of thermal imaging identified obvious thermal defects, their qualitative analysis and recommendations for elimination (method of passive thermal control) are made.
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SAFETY ASSESSMENT OF DAMS MADE OF GROUND MATERIALS

https://doi.org/10.34031/2618-7183-2019-2-4-45-49
Abstract
The stability of the dam on Rogunskaya HPP made of ground materials is studied on the basis of numerical calculations of its spatial stress-strain state. The deformation and strength properties of the materials com-posing the dam body defined in the triaxial compression devices were used in the calculations. Limit values of strength properties of materials and controlled values of diagnostic indicators of a dam at which safety of its work is provided are established.
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EXTERNALTRANSLUCENT COATINGS DEVICE WITH THE USE OF GLASSPROFITE AND COMPOSITE MATERIALS

https://doi.org/10.34031/2618-7183-2019-2-4-50-55
Abstract
The article raises issues related to the use of profile glass (glass profilite) in the device of external vertical enclosing structures of modern building systems. There is a need for a combination of composite materials, especially foam composite, in the manufacture of translucent enclosing structures, which greatly reduces the weight of the outer panels and increases their heat and sound insulation characteristics. It is emphasized the need to consider the issues of energy efficiency not only at the stage of operation of the building, but also at the stage of its construction, as energy efficiency is not only the ability to save heat at the stage of operation of buildings, but also high technological performance of works at the stage of their construction.
The novelty of this study is just the design of the wall panel with a possible combination of two materials – profiled glass and foam. The article describes in detail not only the design of the panel itself, but the technology of its manufacture, as well as the technological processes associated with the device of enclosing structures. Two variants of connection of wall panels with floor slabs are considered and connection nodes are given. Based on the analysis of a number of scientific publications, the variants of the mechanisms used for the installation of panels taking into account the nodes of the connection of structural elements – the panel itself and the floor slabs are considered. Due to the fact that the article discusses the use of boxed glass, emphasizes the need to continue the study in order to identify the possibility of using other types of glass (channel, ribbed, edged) for the manufacture of multi-component wall panels, taking into account the climatic conditions of the regions.
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COMPARATIVE EVALUATION OF ROAD PAVEMENT STRUCTURES USING CEMENT CONCRETE

https://doi.org/10.34031/2618-7183-2019-2-4-56-63
Abstract
The results of studies on the use of modified basalt fiber reinforced cement concrete coating in the design of hard pavement are presented. It is shown that the use of fiber cement concrete in road structures allows to reduce the thickness of the coating, while having a margin of safety in the concrete layer, and the frame of micro-reinforcing components allows to reduce penetrating loads.
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COMPLETE SOLUTION OF LAME PROBLEM FOR A THICK-WALLED COMPOSITE NONLINEARLY DEFORMABLE CYLINDER

https://doi.org/10.34031/2618-7183-2019-2-4-64-72
Abstract
The paper deals with the boundary value problem for the nonlinearly deformable composite cylinder with different types of boundary conditions. The stresses and displacements on both boundaries of the cylinder are constant, so their boundary average values for any area are constant and equal to the initial values. It should be noticed, that the solution of the boundary value problem is obtained without using nonlocal hypotheses about the composite material volume smallness by the angle for which the effective characteristics are calculated. In addition, the assumption of the composite material element smallness in the radial direction with respect to the thickness of the cylinder is used. It is established, that there is no possibility to consider plane stress state and plane strain of the cylinder separately from each other. Both of these states should be studied for analysis of stress-strain state according to Voigt and Reuss hypotheses. It is also shown that the solution of the Lame problem for a cylinder, which is derived, based on Voigt and Reuss hypotheses, is self-sufficient. Formulas, which describe stress-strain state of the composite cylinder, are derived based on this approximation.
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ORGANIZATIONAL AND ECONOMIC PROBLEMS OF ENVIRONMENTAL SAFETY IN CONSTRUCTION

https://doi.org/10.34031/2618-7183-2019-2-4-73-78
Abstract
To date, to identify, analyze and account the direct and indirect effects of environmental impact during the planning of design solutions for the construction of facilities, it is necessary to carry out an environmental impact assessment. The results of this assessment determine the consequences of the implementation of a particular construction project, i.e. changes that can occur in the environment, including in the lives of people, potentially possible after the implementation of construction. The results of this assessment are objective information about the future state of the environment of the territory to decide on the implementation of the planned project. The economic component of this assessment is to determine the cost of implementation of measures to protect the environment of the territory.
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