V.F. Muschanov, A.I. Demidov
An Elastic-Plastic State of a Circle Toroidal Shell with a Rectangular Opening
The Donbas National Academy of Civil Engineering and Architecture
Abstract. This article is devoted to the use of the technique developed for determining a plasto-elastic stress-strain state of arbitrary curvature shells on the base of the theory of small plasto-elastic deformations. Linearization of task solution is done by the method of elastic solutions. Lagrange’s variational equation in the form of point displacements of a shell middle surface in finite differences is used in every approximation. When writing down Lagrange’s variational equation a functional dependence between stresses and strains is given in the form of Hooke’s law but with additional members taking into account plastic deformations. Geometrical equations are used in a linear form as Cauchy correlations. A material is characterized by a corresponding tension diagram of a cylindrical specimen, by a normal elasticity modulus, and Poisson’s ratio. Cinematic boundary conditions are exactly met, and static ones on free loose shell edges are met approximately. There is considered an example of calculating a toroidal shell middle surface equations of which are written in a parametrical form. Shell internal and external edges are fastened quite rigidly, and its side faces are hingedly fastened. A shell is weakened by a large unsupported rectangular opening and is loaded with a normal uniformly distributed load. The task is solved by the elastic solution method and the variation-difference method of point displacements of a shell middle surface. The solution is taken as far as numerical results. There are given the fields of intensity of shearing stresses by a shell internal light surface, displacements, axial forces, and bending moments at a plasto-elastic solution of the task for the whole net area. The paper is devoted to an actual problem of structural mechanics of the shells weakened by large openings at the plasto-elastic deformation in a simple loading.
Key words: loose toroidal shell, variation-difference method, boundary conditions, elastic solution method, intensity of shear strains, intensity of shearing stresses, plasticity function.
I.I. Ananyan
Comparative retrospective analysis of changes of normative base of development of dwelling building
The Donbas National Academy of Civil Engineering and Architecture
Abstract. The actual questions of perfection of normatively-technical base of development of dwelling building are examined in the article. Actuality of development of methodology and tool of estimation of potential of dwelling building is conditioned intensifying of contradictions, between possibilities of existent housing fund and variety of necessities of different layers of population in providing of comfort of residence in existent part of housing fund and in the new types of habitation with the various level of comfort in the conditions of market. The practical worker of application of town-planning normality in a historical context on separate questions of planning and building of housing territories lights up. The estimation of efficiency of operating norms is given taking into account changing social basis of society. The suggestion on perfection of norms, regulative building and reconstruction of dwellings territories, answering the aims of social development and increase of comfort of dwelling is contained, and also coopering the rational use of material, natural, natural, power and other types of resources.
Key words: comfort of dwelling building, closeness’s of population, closeness of housing fund, specific size of territory of microregion, differentiation of norms.
V. I. Gotc
Ashfilling binding material and concrete: structure, characteristic, ecological and economic aspects of the fabrication and use
The Kiev University of Civil Engineering and Architecture
Abstract. The next sharpening the ecological problems of the Ukraine requires the development new efficient technology conversions wastes of heat power, presented by ash and slag, which provided the maximum degree to their reclamation and binding in qualitative building materials. The choice of technology for reclamation of wastes is dependent from such factor as their chemical, mineralogical and grinding compositions, value to specific surface and way of the removing. In spite of the fact that specified waste are broadly used for production of bindings systems of the different type such as pozzolanic cements, ash-sulphate cements, gypsum-ash-cement bindings material, alkaline ashes cements, the general volume to their reclamation remains very low. The share of the ash in such system usually does not exceed 25 35 %, but fabrication concrete product on their base requires additional power resources on heat processing. In work is considered possibility of the production of ashfilling binding and concrete that contains in its composition more 50 % ashes. It is shown that when entering the ash in composition concrete mixture amount her can be raised not only to account of the use the different type of activations, but also to account polifunctionality of ash. Its possible entering the ash in composition of binding system also as microfiller and small aggregate, will promote forming the more strong contact ash to account of the increase degree crystal-chemical similarity of new formation and relict reminder that do not yield to the hydration. In ditto time when use overweening amount ashes in composition ashfilling material can exist increasing to porosity and reduction of development strength at time that brings about reduction frost resistance and corrosion resistance. For avoiding of these phenomena’s in composition concrete mixture together with raised by amount of the ash can be incorporated plasticizers additives with different mechanism of the action and complex additives that contains as organic, so and inorganic substances. The researches of operating characteristics of ashfilling concrete are indicative of efficiency change the Portland cement on designed compositions binding material (got with use of wastes of power station) which can be offered as alternative of Portland cement.
Key words: ecology, pozzolanic additives, hydro-removal ashes, fly ash, activation.
K.K. Pushkarova, O.A. Gonchar, O.P. Bondarenko
Features regulation of properties for alkaline blastfurnace slag cement
The Kiev University of Civil Engineering and Architecture
V.D. Glukhovsky Scientific Research Institute for Binders and Materials
Abstract. Today big amount blastfurnace slag cement exists on civil market, which does not attract a following because of his low civil-technological characteristic: he slow hardening than ?ortland cement, and differs the small setting time at initial period of the hardening and particularly – under negative temperature. That is why actual gets old the question about needing of the improvement his characteristic to account of the introduction complex organo-mineral additives that contains as accelerator of alkaline component. It’s considered the opportunity of expansion for setting time and improvements of physico-mechanical properties of blastfurnace slag cement modification by of alkaline complex additives. The results of the study showed a possibility to use a complex organo-mineral additive, which provides the activation of the aluminosilicate component and full binding of the alkalis into insoluble compounds. This was found to allow not only to avoid the inner corrosion of the cement stone as resulting from the presence of free alkali in its composition, but also to provide the required technological and physico-mechanical properties of the modified alkaline blast furnace slag cement concretes. The results of the study will allow getting concretes with the use of the developed modified alkaline blastfurnace slag cements. The results of researches allow to do the optimistic forecast on cause of the possibility of the reception alkaline blastfurnace slag cement with regulated period for setting time and perfected physico-mechanical feature, which will currently use at production of artificial stone for special purpose with forward given technological and service characteristics.
Key words: slags, portland clinker, blastfurnace slag cement, activation, complex additive, setting time, durability.
V.V. Filatov
On the Design of Composite Plates with Alternating Values of Seam Stiffness Factor
Moscow State Building University
Abstract. This article is a result of the development of the theory of designing A.R. Rzhanitsyn’s composite plates. Two-layer composite plates are considered, a seam stiffness in which (x – a stiffness factor of shift bonds) varies by the piecewise-constant law. Cross-section bonds are accepted as absolutely rigid. To solve the system of resolving differential equations there is involved a numerical method of successive approximations (MSA) developed at the faculty “Structural Mechanics”, MGSU. A MSA differential form possesses a high accuracy and allows considering breaks of the functions and their first derivatives. The algorithm offered is illustrated on the example of designing a square two-layer plate pin-supported along the whole contour under loading evenly distributed on its surface. A spasmodic change of the stiffness factor of shift bonds in two directions is set. There are given the design results. An opportunity of using the technique for designing multilayered plates is shown.
Key words: theory of designing A.R. Rzhanitsyn’s composite plates, stiffness factor of shift bonds, multilayered plates.
H.A. Benai
Problems of town planning in donetsk region
The Donbas National Academy of Civil Engineering and Architecture
Abstract. The article is devoted to the state of observation of the history of town planning in Donetsk Region. There are given results of the analysis of a planning structure of Donetsk Region towns. It is shown how architecture influences different processes in the sphere of the up-to-date town planning; there are given recommendations on an optimal use of disturbed areas. There are taken up town planning problems and ways of their solution.
Key words: town planning, planning structure, disturbed areas, rehabilitation.
S.S. Bula
Definition of curvature and temperature force in noncentral pressed reinforced concrete elements under local heating and exploitable loading
National University “Lvivska polytechnika”
Abstract. The article gives main results about investigations of curvature and temperature strength in noncentral pressed reinforced concrete elements under different loading levels and local heating of pressed or stretched side. The method of testing experimental constructions under loading and local heating is described. There are presented the results of experimental investigations and theoretical equals for determining of temperature extending and temperature curvature in noncentral pressed reinforced concrete elements. The changing of temperature force and temperature curvature depending on heating placement and loading level are investigated. The results of investigations were quantitative and qualitative indices of temperature curvature and of temperature force changing under loading and local heating in noncentral pressed reinforced concrete elements. The presented investigation oriented to improving of calculating method of constructions under local heating.
Key words: local heating, curvature, temperature strength.