BUILDING & CONSTRUCTION JOURNALS IN SCOPUS
Pages 5-7
DOI: 10.22227/1997-0935.2016.7.5-7
Articles count - 13
Pages - 151
Pages 5-7
DOI: 10.22227/1997-0935.2016.7.5-7
Pages 8-17
The proportions of buildings, design and building materials in traditional Muslim architecture depended on geoecological factors of different regions of Islamic countries. One of those factors is a high seismicity site. It had the greatest influence on the appearance of monuments in the selected region. The influence of seismicity on the architecture of the buildings is considered in the article on the example of the architectural monuments of the Republic of Uzbekistan - madrasah of Ulugbek of the 15th century in Samarkand, the Kalyan mosque in Bukhara and the Syrian Umayyad mosque (708 buildings) in Damascus. The seismicity of the region is high. In order to determine the seismic resistance of architectural monuments the requirements SP 14.13330.2014 (the Current set of rules “Construction in seismic regions” (Seismic Building Design Code), revised edition of SNiP II-7-81*) and the Eurocode EN 1998-1 were used. On the basis of calculations tables comparing performance were made. The structural characteristics of monuments were compared with the characteristics required by the standards. The point value of seismicity of the territory which ensured the stability of the buildings was determined. Comparing the proportions of the monuments with Russian and European regulations on earthquake-resistant construction, we demonstrated the compliance of their architectural forms with the seismic activity of the area. Traditional architecture evolved from random search under the influence of the centuries of experience protecting the buildings from adverse natural influences. The design and shape of these ancient Muslim buildings, limited by the requirements of seismic resistance, has been subsequently reiterated in other structures, determining the style of Muslim architecture. The analysis allows us to see how the architects used the general principles of earthquake-resistant construction on different buildings. The destructions during earthquakes occurred only after structural deterioration of the materials, and were local in nature. Most of the buildings have symmetrical structure, the corresponding proportions in plan and in height, with using materials of sufficient “strength and elasticity”. The whole appearance of the buildings and the architectural style is not accidental. The proportions of the buildings - the height, width of span load-bearing structures, walls and openings, the symmetry of the buildings, domes, arches, windows, all structural dimensions were dictated by the requirements of seismic resistance.
DOI: 10.22227/1997-0935.2016.7.8-17
Pages 18-35
The author considers the results of experimental studies of the influence of some factors on the sloping section bearing capacity. These factors are: the value of the relative distance from the support to the load line (shear span) depending on the quantity of transverse reinforcement and the shape of the cross section of the elements; the size of compression flange overhang in T-section beams; the prestress rate of the transverse reinforcement. The author specifies the types of fracture across sloping sections of T-section beams.
DOI: 10.22227/1997-0935.2016.7.18-35
Pages 36-45
This paper presents t experimental and numerical studies of cracking in the thick-walled filament-wound cylindrical shells made of fiber reinforced plastic during the manufacturing process (specifically, in the process of curing and cooling). The experiments have shown that, when the cylinder is cooled by optimum cooling regime, at the end of the cooling process the obtained cylinder is monolithic and without ring cracking. In this regard, the residual thermal stresses in thick-walled cylinder in the cooling process is calculated using finite element method with account for transient heat conduction and the temperature dependence of the mechanical properties of the material and the viscoelastic behavior of the polymer. The calculations are conducted for cooling in standard and optimum regimes. The results showed that the maximum radial stress in the most dangerous initial area is several times less when the cylinder is cooled down in the optimum regime than when it is cooled in the standard regime.
DOI: 10.22227/1997-0935.2016.7.36-45
Pages 46-56
The authors considered the problem of load distribution in an elastic base of a die of rounded (parabolic) shape, which is under the impact of regular evenly distributed load at different values of frictional coefficient at its base. The components of the loads are determined, which depend on Poisson’s ratio. It is proved that loads distribution in the base of a die depends on the coefficient of lateral pressure of soil and frictional coefficient. The authors offer the formulae of pressure and lateral pressure under the die.
DOI: 10.22227/1997-0935.2016.7.46-56
Pages 57-66
In the article the author considers the questions of secondary use of organic liquid products, which are formed during the high temperature cleaning of the equipment for producing thermoplastic polymer polyamide 6, polyethylene, polypropylene. On chemical and petrochemical plants producing or processing thermoplastics, the recycling waste, including drilling fluids are quite a current issue. The authors of the article conducted a research on the possibility of applying flush fluids used for the modification of petroleum bitumen and as a basis of protective coatings for concrete, reinforced concrete. During the research it was found out that washing liquid can be used for modification of petroleum bitumens. The organic phase of drilling fluids and dissolved thermoplastics and products of their thermo-chemical destruction are similar in chemical nature and represent a stable dispersed system with surface-active properties. The experiments have shown their compatibility with oily carbonic acids, alcohols, their esters, as well as oil, vegetable, synthetic oils, organic solvents, synthetic resins and bitumen. The main purpose of the study is to reveal the effect of additives to polymers-containing drilling fluids on the properties of epoxy-bitumen coating for concrete and reinforced concrete. The results showed that the test fluids are effective modifiers of oil and bitumen, epoxy-bitumen coatings, improve their physical and mechanical properties and above all increase the adhesion strength of the coating with the concrete. The studies revealed the feasibility of the secondary usage of waste of polymer-containing liquids as modifying additives for petroleum asphalts and coatings on their basis.
DOI: 10.22227/1997-0935.2016.7.57-66
Pages 67-80
The paper presents the research results of the influence of coating color on the change in decorative characteristics of polymer composites based on epoxy resins under the action of climatic factors. A quantitative description of color was performed by the method of direct scan based on the subtractive color model CMYKH. In the study, we proposed mathematical models allowing estimating the change in color saturation of polymer composites, depending on the duration of exposure, total solar radiation and ultraviolet radiation ranges A and B. We have established an increase of the reliability of approximation when using solar radiation parameters as varied factors.
DOI: 10.22227/1997-0935.2016.7.67-80
Pages 81-90
The authors consider the prospects of the use of shotcrete on the basis of fine-grained concrete mix for the construction of underground. Such use has the following advantages: there is an increase of the construction speed due to high feed rate of rapidly fastening concrete mix that has good adhesion to other materials; thanks to solid structure the obtained concrete has high water resistance and therefore it can be used in the construction of underground structures undergoing high pressure of groundwater; using reinforcing mesh it is possible to create thin-walled dome vaults in underground structures, as well as to obtain a reinforced layer of a heavy thickness, which has high strength and good adhesion to rocks due to the use of metal mesh, steel frame, anchors and introduction of dispersed steel or carbon fibers that can be used in the construction of large tunnels. The obtained experimental results showed that the fine-grained concrete mixture containing superplasticizer Ace 388 applied by gunning, has a low water-cement ratio, which provides its fast setting and hardening, although it contains a substantial amount of fine powdery or fibrous materials having a high water demand. The compressed air pressure required to ensure the smooth transportation of fine-grained concrete mix to the placing site, depends on its viscosity and moisture.
DOI: 10.22227/1997-0935.2016.7.81-90
Pages 91-100
This article presents the results of research on one of the possible ways of recycling the concrete scrap waste to obtain environmentally friendly building materials on its basis, in particular bending elements. According to test results of the samples of concrete lintels the theoretical moment of cracking and breaking load was determined. The comparative studies on the series of prototypes showed that under short-time loads the deformation of samples based on secondary crushed stone is almost identical to the deformation of specimens based on natural gravel. In this case the bearing capacity of two series of prototypes of reinforced concrete lintels showed the average difference between each other of not more than 3.4 %. The proposed concrete mix based on crushed chip made of recycled waste of concrete scrap of the fractions from 5 to 10 and from 10 to 20 mm allows producing heavy concrete of the required strength and deformability characteristics, which is essential in creating products and structures with high and reliable performance in difficult conditions.
DOI: 10.22227/1997-0935.2016.7.91-100
Pages 101-113
Investigation of landslide processes has always been and still is a topical issue in economic activity and particularly in the construction field. Because of possible landslide displacements of soil on slopes there is a danger of the loss of stability of buildings and structures. There are a lot of examples of it. The authors consider the questions of mechanical and mathematical justification of the conditions when the moment of landslide movement and the forces acting in it occurs. Basing on the known technical characteristics of landslides the authors offer a calculation method of displacement force for landslide bodies different in class depending on their mass and acceleration. Landslides require full-scale studies in the landslide area, the most important of which is geodetic monitoring. Geodetic observations allow not only determining the absolute values of numerical characteristics of landslide, but also their preciseness and, consequently, evaluating the reliability degree of the forecast of landslide risks and safety for the construction objects and possible social and economic consequences.
DOI: 10.22227/1997-0935.2016.7.101-113
Pages 114-133
The authors solve the task of water permeability of a channel lining with colmated seams with the help of conformal mapping method and Christoffel-Schwarz integral without regard and with regard of permeability of the foundation. Approximate calculation dependencies of fseepage features for a number of special cases were found out, including in case of very low values of screen damage and low modules of elliptic integral close to zero. The results of specific seepage discharge calculation of a colmated seam basing on different formulas were compared. These formulas were obtained by the authors of the article basing on the known dependencies. The calculated values of water permeability coefficient of seals were compared with field data and showed close agreement. The calculated values of pressure gradient in the seal base do not exceed the critical values allowed by the current standards.
DOI: 10.22227/1997-0935.2016.7.114-133
Pages 134-141
The speed limiter is intended to actuate the safety gear excess of emergency overspeed of the car or the counterweight while moving down. In Russia, the most widespread speed limiters are centrifugal type with a horizontal axis of rotation. Their design and methods of calculation are well known and widely presented in the literature. In foreign practice the most often used speed limiters include inertial roller in their construction. In the domestic literature there is almost no description of such structures and principles of their calculation. In the given article the author describes the calculation and structural scheme of the speed limiter with inertial roller and an octagonal disk of Schindler Co. Equilibrium equation actuating lever relative to the axis of rotation is compiled. On the basis of the analysis of the equilibrium equation the basic principles and constituent elements of the calculation of the elevator speed limiter with inertial roller are discovered. These are: calculation of the lever system, calculation of the spring, calculation of the disk. The dependences of the path, speed and acceleration of the roller in time are given. It is convenient to design the disk surface with the use of computer applications. This eliminates a significant amount of computation. The design algorithm for disk surface on a computer is given. The example of design of disk surface using this algorithm is offered. The proposed considerations on building the speed limiter’s disk surface allow changing its profile in real time. This, together with the equilibrium equation allow designing speed limiters with an inertial roller in any possible configuration.
DOI: 10.22227/1997-0935.2016.7.134-141
Pages 142-151
Classification of the processes in an enterprise is a methodical basis for the solution of the problems of identification and reference of processes to concrete category depending on a classification sign that in turn is the basis for the choice of management tools of the processes and of an enterprise in general. The classification of processes is one of the problems of information search consisting in reference of the process to one of several categories on the basis of certain classification criterion. Rather often some authors make terminological mistake in their works when they refer to all the processes at an enterprise to the category “business process”, including management processes, and supporting processes. The classification of the processes of an enterprise has to be carried out with a definite purpose: it can be carried out for ensuring systematic studying and completeness of coverage of the studied subject domain, or for the purpose of business management on the basis of process approach. The first purpose provides exclusively analytical character of solvable tasks of studying the processes of the enterprise and doesn’t allow developing recommendations on the solution of management problems of the organization. In the second case it is quite possible to use classification of processes of an economic entity as a business management mechanism basis on the ground of process approach. According to the offered classification three groups of processes of the enterprise are defined: management processes (management), business processes (the main processes) and the providing (auxiliary) processes. These classification criteria will allow identifying the processes of the enterprise and defining the system of their interaction. The hierarchy level of the processes allows determining the duration of life cycle of the processes and is the basis for processes planning. Vertical and horizontal processes allow defining the roles, powers and responsibility of linear and functional heads of the organization. Depending on the scale of the organization the presented classification can be concretized concerning business processes. The developed classification allows referring any process of the enterprise to one of the categories, determining the level of its hierarchy and its orientation which is a basis of the choice and formation of management instruments of processes and of an enterprises in general.
DOI: 10.22227/1997-0935.2016.7.142-151