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2019

Archives Journal Construction Materials and Products Vol. 2

COMPARATIVE EVALUATION OF ROAD PAVEMENT STRUCTURES USING CEMENT CONCRETE

https://doi.org/10.34031/2618-7183-2019-2-4-56-63
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 56-63 p.
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
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 64-72 p.
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
 73-78 p.
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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THE USE OF THE NATIONAL ORNAMENT OF THE KABARDINS AND BALKARS AS ARCHITECTURAL DECORATION OF FACADES OF BUILDINGS

https://doi.org/10.34031/2618-7183-2019-2-4-79-83
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 79-83 p.
Abstract
The article presents the results of research on the use of the national ornament of the Kabardins and Balkars as an architectural decoration of facades of buildings, contributing to the increase of architectural and artistic expression of facades of buildings. Classification of the national ornament of the Kabardins and Balkars is given, stylized schemes of the national ornament are considered and variants of their placement on facades of buildings as an architectural decor are offered.
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BUILDING MATERIALS AND TECHNOLOGIES OF MODERN HOUSING: ARCHITECTURAL AND ENVIRONMENTAL ASPECTS

https://doi.org/10.34031/2618-7183-2019-2-4-84-88
 84-88 p.
Abstract
The questions of architectural and environmental solutions in the field of design and construction of low-rise residential buildings, including the distinctive properties of building materials due to the conditions of modern material culture, aesthetic features of the external and internal appearance of these buildings are considered. It is noted that the conceptual approach to the choice of technologies in the construction of these objects helps to determine the necessary organization and structure of work, as well as additional artistic methods of architectural expression. It is also indicated that along with the architectural expressiveness one of the main requirements for the comfort of living in a residential building becomes environmental safety. Considerable attention is paid to modern building materials and innovative technologies that form new crea-tive challenges facing architects.
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THE MANIFESTATION OF FRACTAL DIMENSIONS IN THE ARCHITECTURE OF BUILDINGS AND STRUCTURES

https://doi.org/10.34031/2618-7183-2019-2-4-89-95
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 89-95 p.
Abstract
The article shows the presence of proportional correspondence of parts and the whole using the principles of fractal geometry in the formation of the concept of beauty of natural objects and phenomena. The objects of the artificial environment for the formation of images on the example of mathematical models of calculation of natural objects that have the properties of fractal are investigated. The article presents the types of fractals. Examples of fractal in physics, biology, chemistry are given. Fractal geometry can and should be used in modeling the structure of the artificial environment that humanity creates through architecture. The very process of designing a single building, and its integration into the urban environment, which in the process of formation is also quite chaotic, falls under the principles of fractal geometry. Modeling of these processes using the principles of fractal geometry allows not only to create the most comfortable artificial urban environment, but also to monitor the flow of all processes within it.
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CHEMICAL REACTIVITY ASSESSMENT METHOD OF NANOSTRUCTURED LOW CALCIUM ALUMINOSILICATES

https://doi.org/10.34031/2618-7183-2019-2-3-5-11
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 5-11 p.
Abstract
Nowadays, the production of high-performance composites is a relevant objective in construction industry. Normally, geological and/or technological conditions of phase formation are responsible for chemical and structural characteristics of raw materials. In this regard, the use of a certain material dictates terms to opti-mizing production process, efficient use and, therefore, requires to develop a method for quality evaluation of raw materials. This approach allows a considerable time saving and raw materials sources, while the evaluation of final performance characteristics of designed materials is being done. The biggest interest in this area is focused on new types of developed and poorly-studied composite systems which results in a lack of capacity to design materials with known performance and, therefore, constrains the areas of application of construction composites
Among such composite systems there are zero cement alkali-aluminosilicate systems or geopolymers. For geopolymers production a wide range of different aluminosilicates with varied characteristics potentially can be used. And also, in each certain case, the quality evaluation methods for aluminosilicates should be different.
This study is focused on chemical reactivity assessment method of crystalline (mainly, nanocrystalline) low calcium aluminosilicates exposed to high-alkali media. The solubility degree in high-alkali media and compressive strength performance were evaluated in this study in order to define chemical reactivity of low calcium aluminosilicates. The compressive strength data demonstrated a positive correlation with the crystallinity degree of aluminosilicates.
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APPLICATION OF STEPWISE AND ITERATIVE METHOD IN THE CALCULATION OF BENDING PRESTRESSED PRECAST AND MONOLITHIC ELEMENTS TAKING INTO ACCOUNT PHYSICAL NONLINEARITY

https://doi.org/10.34031/2618-7183-2019-2-3-12-27
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 12-27 p.
Abstract
Precast and monolithic reinforced concrete structures with and without prestressing armature voltages are used as newly designed independent ones, and are the result of work to strengthen existing structures by in-creasing the cross section. In both cases, the cross-section of such elements is considered as a two-layer, and the resulting composite element operates under load in conditions distributed between the layers of internal forces, the mechanism and the actual value of the distribution of which depends on the physical and mechanical characteristics, the design scheme and the parameters of the contact interaction of the layers. When calculating and designing prestressed reinforced concrete precast and monolithic elements, the shear seam compliance is usually not taken into account, which complicates the analysis of the actual stress-strain state of the structure and contains a certain undisclosed potential for its rational design. One of the possible directions in solving the problem, taking into account the shift of the contact seam, is the use of variational principles of structural mechanics in the calculation of structures such as composite cross-section rods. In the framework of this work, the questions of practical applicability in the structural analysis of composite reinforced concrete precast-monolithic rod of variation principles of structural mechanics based on the method of V.Z. Vlasov – I.E. Mileykovsky in the form of displacements in combination with the stepwise-iterative method of calculation are considered. The results of numerical calculations by the proposed method are presented, which allows to take into account the specifics of the shear bonds of the precast and mono-lithic layer, to carry out practical accounting of the seam compliance, as well as to take into account the physical nonlinearity of the characteristics of materials, which allows the rational design of precast monolithic structures.
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EVALUATION OF THE SEISMIC INERTIA FORCES ON THE ACTUAL DAMAGE OF BRIDGES

https://doi.org/10.34031/2618-7183-2019-2-3-28-33
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 28-33 p.
Abstract
Because of the constant threat of earthquakes in seismic hazardous areas, it is necessary to study the issues of seismic resistance of structures and development of methods of their design, taking into account the seismic factor. A significant share in the total volume of engineering structures permanent and built on canals and roads is occupied by artificial structures, such as aqueducts, small and medium bridges (overpasses). In this regard, the provision of seismic resistance of these structures is of practical interest. Buildings and structures located in seismic areas are affected by factors that cause the occurrence of seismic forces and changes in the working conditions of structures during earthquakes The article presents the results of comparison of calculations in the dynamic theory (by the method of spectral curves) and static seismic coefficient determination with the actual data on damage to structures in strong earthquakes. A formula for calculating the coefficient of seismicity is proposed.
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RELEVANCE OF THE CREATION OF ARTIFICIAL BREATHING ATMOSPHERES IN TERMS OF AIR POLLUTION

https://doi.org/10.34031/2618-7183-2019-2-3-34-40
 34-40 p.
Abstract
At present, the problem of air quality in large cities with a large number of cars and industrial enterprises is acute. Normative documents on the basis of which the ventilation system is designed regulate the cleaning of the outside air from dust. Purification from gaseous contaminants as well as suspended aerosols such doc-uments do not regulate. According to the results of the study of air quality in Moscow over the past few years, an increased content of pollutants such as NO, CO, CO2, SO2 has been registered. Near busy highways during “rush hours” the vehicles locally “burn” oxygen in the air and emitted products of combustion even more reduce the relative concentration of oxygen in the air. Also, a large number of pollutants come from industrial and agricultural enterprises. The use of additional purification filters in ventilation systems, such as photocatalytic filter, adsorption filter can reduce the concentration of gaseous pollutants to an acceptable minimum, but they will not solve the problem of low oxygen content. Inhalation of air in excess of MPC for a long time may cause irreversible health effects. In this regard, the task of creating artificial respiratory atmospheres becomes relevant. The greatest relevance of air quality and sufficient oxygen content is for children's institutions, as well as special services, the work of which is associated with an increased concentration of attention. The problem of air pollution with aerosols and fine dust has become particularly relevant due to the significant increase in respiratory tract diseases and various allergies.
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