PATRIOT, SOLDIER, BUILDER
Pages 5-9
DOI: 10.22227/1997-0935.2016.5.5-9
Articles count - 13
Pages - 139
Pages 5-9
DOI: 10.22227/1997-0935.2016.5.5-9
Pages 10-17
A number of researchers are working on the creation of a general method for forecasting operability and residual life of engineering constructions of buildings and structures of different purposes using the models of nonlinear physical wear development. The authors analyzed two approaches to forecasting operability and estimating residual operating life of structural elements of residential houses using nonlinear models of the changes in physical wear of building structures basing on forecast logistic model. The description of the differences in the approaches to forecasting and advantages of one method compared to another are given. As a result of the conducted analysis the authors recommend the most accurate model for making predictions and estimation of residual operating life of building structures.
DOI: 10.22227/1997-0935.2016.5.10-17
Pages 18-27
The article discusses some features of planning solutions of apartments in the architecture of Yerevan, which are typical to different periods, since the turn of 19-20th centuries to the present day. Housing is the chief determinant of human activity. In the process of societal development the house is the foundation of a family, and the family, on its turn, is the key to the stable state. Nevertheless, the time influences the residential architecture. Societal progress periodically affects the living environment. Therefore, housing formation process never reaches the stage of completion: it is always in an endless process of development. The above mentioned primarily concerns the evolution of the planning structure of the apartment. In this context, the dynamics of evolution of housing in Yerevan has accelerated in the second half of the 19th century. The centuries-generated space-planning system of apartment begins to develop in accordance with the rapid changes of social, urban planning and life processes of the time (extension of industry, formation of new socio-economic relations, rapid growth of population, acceleration of construction processes). The impetuous transformation of the dwelling structure is reflected in the complex process of evolution - starting from the traditional houses and ending with the apartments in high-rise buildings. The research of the problems of the traditional dwelling structure, its transformation in the first apartment buildings and diverse improvements of apartment planning solutions contributes to the definition of the main development stages of the dwelling units during the last century, which are observed in the article. Identification of the characteristics of each stage and the multilateral evaluation of different qualities of spatial-planning arrangement of apartments allow working out proper solutions for dwelling units in the future.
DOI: 10.22227/1997-0935.2016.5.18-27
Pages 28-38
The author offer transforming the diagram of ideal elastic-plastic deformations for the description of the stress-strain state of embedment of reinforcement behind a critical inclined crack at repeatedly repeating loadings. The endurance limit of the adhesion between concrete and reinforcement and its corresponding displacements in case of repeated loadings are accepted as the main indicators. This adhesion law is the most appropriate for the description of physical and mechanical phenomena in the contact zone in case of cyclic loading, because it simply and reliably describes the adhesion mechanism and the nature of the deformation, and greatly simplifies the endurance calculations compared to the standard adhesion law. On the basis of this diagram the author obtained the equations for the description of the distribution of pressures and displacements after cyclic loading with account for the development of deformations of cyclic creep of the concrete under the studs of reinforcement.
DOI: 10.22227/1997-0935.2016.5.28-38
Pages 39-51
The article is dedicated to the problem of geotechnics. The problems of the weak soil base are topical. Also there sometimes happen severe accidents of soil mass. A great number of such emergencies is of a progressive character, when a local crash leads to the crash of the whole construction. Tarring the soil with epoxy can ensure geotechnical safety of the basis. That’s why the improvement of this method is needed in order to reduce yielding of the base, create ground water cutoff or create building hoisting. In the article new structural solutions for reduction of settlement are presented. The authors suggest using the manufactured plane elements containing epoxy. Such elements have different sizes and lie underneath the foundation. Similar structural scheme can be used to reduce soil settlement. The authors carried out two series of plate-bearing model tests with manufactured plane epoxy elements. In the first series of tests the biggest element was closer to the foundation, the smallest element was closer to the biggest element. In the second series of tests the smallest element was closer to the foundation, the biggest element was closer to the smallest element. After the end of plate-bearing model tests the authors received values of the base settlement and the dependency diagrams “base settlement-soil pressure”. The new structural solution for reducing soil settlement proved to be effective. Settlement of base decreased sevenfold.
DOI: 10.22227/1997-0935.2016.5.39-51
Pages 52-58
The underground space is widely used in the construction in big cities of the Russian Federation. These works need the use of elevating-transfer vehicles. In this case the requirements of norms and regulations on operating safety should be strictly observed, because their breach often leads to emergency situations and injuries. The organizational and technological solutions when developing the design documentation and executing construction and assembly works should be primarily based on the stability of lifting facilities. The author states the requirements to installation of lifting tackles (cranes). The features of their installation in different operation conditions on construction sites are described. The crane stability depends on many different indicators, which are considered by the author. The calculation algorithms of crane stability are offered.
DOI: 10.22227/1997-0935.2016.5.52-58
Pages 59-71
The investigations of thermal and technical features of enveloping structures show that at the present time the structures of outer walls with hinged ventilated facades are the most energy efficient. The facades with air space are widely used both in residential and in public buildings. In the recent years the problems related to energy efficient enveloping structures are being actively investigated. The problems of modern Russian and foreign energy-efficient facade systems, their technical and structural solutions and the main methods of their installation are reviewed in the article. The methods of solving the tasks of research are proposed and the obtained results are described. The development of organizational and technological solutions for sealing of joints of front panels during installation of ventilated facades by pre-assembly method was the basis of the method of solving of the problem. The obtained data together with the developed structural and technological solutions may become the base for the development of technical rules and regulations.
DOI: 10.22227/1997-0935.2016.5.59-71
Pages 72-81
The paper deals with the development of composite binders for producing concrete with improved characteristics of gas, water and vapor permeability. The authors investigate the processes of composite materials formation in order of decreasing scale levels from macro to nanostructures. The criteria for optimization of the volume of dispersed additives in concrete are offered. The authors theoretically studied the technological features of the formation of hydrated cement stone structure. A positive effect of nanodispersed additives on the structure and physico-mechanical properties of cement composite materials are predicted. Thanks to its improved features, such as good ratio of strength and body density, high density and lifetime, the modified concrete may be used when solving various practical tasks of the construction branch.
DOI: 10.22227/1997-0935.2016.5.72-81
Pages 82-92
Different aerated mortars are used for pargeting of walls made of aerated concrete. Though the regulatory documents don’t specify the dependence of plaster density from the density grade of gas-concrete blocks. In case of facing of gas-concrete blocks with the grade D500 using plaster mortars with the density 1400…1600 km/m3 there occurs a dismatch in the values of thermal insulation and vapor permeability of the plaster and base. The authors suggest using dry mortars for finishing of gas-concrete block of the grades D500 и D600, which allow obtaining facing thermal insulating coatings. The efficiency of using four different high-porous additives in the lime dry mortar was compared. They were: hollow glass microspheres, aluminosilicate ash microspheres, expanded vermiculite sand, expanded pearlitic sand. The high efficiency of hollow glass microspheres in heat insulating finishing mortars compared to other fillers is proved.
DOI: 10.22227/1997-0935.2016.5.82-92
Pages 93-106
Monitoring of production resources is a large-scale and complicated measure, the results of which are necessary for the state and for private entrepreneurs. There are many approaches to conducting such a monitoring, which firstly base on the information request from the suppliers of the resources by governmental bodies. The authors offer a new approach to data collection, which takes into account the technical achievements of the Russian economy. The main instrument of this approach is geoinformation technologies.
DOI: 10.22227/1997-0935.2016.5.93-106
Pages 107-118
At the present time risk management is an integral part of state policy in all the countries with developed market economy. Companies dealing with consulting services and implementation of the risk management systems carve out a niche. Unfortunately, conscious preventive risk management in Russia is still far from the level of standardized process of a construction company activity, which often leads to scandals and disapproval in case of unprofessional implementation of projects. The authors present the results of the investigation of the modern understanding of the existing methodology classification and offer the authorial concept of classification matrix of risk management methods. Creation of the developed matrix is based on the analysis of the method in the context of incoming and outgoing transformed information, which may include different elements of risk control stages. So the offered approach allows analyzing the possibilities of each method.
DOI: 10.22227/1997-0935.2016.5.107-118
Pages 119-129
The construction industry is one of the key fund-creating industries, the formation of the Russian economy greatly depends on it. The construction sector is cyclic, that’s why it has always been sensitive to the tendencies of the national economy. In the contemporary conditions of weak economical climate the construction industry is in a state of sluggish recession. The key indicators exercising restraining influence on the construction complex are analyzed. The author carried out calculations of the prices for residential real estate in the past years. The author’s view on the near-term prospects on the exit from recession state is formulated. From the view of the today’s state and the nearest development prospects, it can be stated that the construction industry is one of the most problematic among the basic economic sectors. Retrieval of the expansion rate of the construction industry is possible in case of the positive changes of general economic state.
DOI: 10.22227/1997-0935.2016.5.119-129
Pages 130-139
The article deals with the problems of studying the process of dispersing liquid fuel and water-fuel emulsions, in particular the characteristics of the dispersed spray in high-potential electrostatic fields. The paper deals with the development of a research method for disperse characteristics of liquid fuels, in particular, the changes in the diameter of the spray particles of liquid fuels and water-fuel emulsions based on them, depending on the intensity of high-grade electrostatic field. These studies are relevant in the creation of new devices based on new dispersion, which are not currently used for fuel atomization and combustion devices, in particular based on the electrostatic dispersion. The currently available methods for assessing dispersion are based on the evaluation of the particle diameter, which are formed by dispersing (particle breakage) of the liquid fuel. The views expressed in the course of the study suggest that the dependence of the particle diameter from the electrostatic field can be estimated not only in case of the destruction of the particles (dispersion), but also in case of the formation (growth) of drops during the expiration of the capillary. In order to confirm the provisions the authors developed the installation and technique to study the changes in the dispersion in dependence with the voltage value of high potential electrostatic field. The results of experimental studies are presented and experimental graphics are built for F5 bunker fuel and water-oil emulsions with different concentrations based on it. On the basis of the experimental data processed by correlation analysis method the authors obtained the mathematical model of diameter changes of the particles under the influence of an electrostatic field, which corresponds to the theory of electrostatic dispersion. The developed technique greatly simplifies the determination of the disperse characteristics of liquid fuel in case of electro-static dispersion.
DOI: 10.22227/1997-0935.2016.5.130-139