When forming in the process of centrifugation an annular section by the method of ""separate"" concreting with the formation of a section of the product at the first stage from the original, including fine-grained concrete mixture, and with the introduction of a coarse aggregate at the second stage into the formed circular section, followed by the final formation of the section and compaction of the concrete mixture by centrifugation, the speed, calculated for the compaction stage, increases, depending on the section zone, the concrete compressive strength from 20% up to 47%, the initial modulus of elasticity from 6 to 19% relative to single-stage centrifugation. The ratio vint / vext of ultrasonic pulse velocities for surface sounding along the inner (vint) and outer (vext) faces of a centrifuged annular section can be considered as a conditional indicator of the uniformity of the concrete structure over the cross section of a centrifuged product. Key words: centrifugation, separate concreting, structure homogeneity, strength and deformation properties, porosity.

Keywords: centrifugation, separate concreting, uniformity of structure, strength and deformation properties, porosity

Within approaching the plane-stress state the problem of a high-speed rotating disk being under side pressure is considered. Within the model of a perfect rigid-plastic body and the Mises yield criterion the values of external parameters for which the plastic zones appear have been defined. The stresses in plastic zones are obtained from the solution of the Cauchy problem, which includes two differential equations to define the stress tensor nonzero component. In order to estimate the stress state in the elastic zone the equivalent stress is introduced. The maximum allowable values of external parameters are obtained from the solution of the problem when the disk is in the limit state. The numerical results are represented as the stress vector hodograph.

Keywords: the plane-stress state, Mises yield criterion, the equivalent stress, an elasto-plastic solid, a rotating disk, a stress vector hodograph

The article examines the influence of observance of the frame dome-shaped roofs assembly technology on the quality of the completed object. This theme is relevant enough, as the building roofs, constructed in accordance with the aforementioned technology, are often found in modern business clusters. It`s natural that prospective investors are interested in perfect quality and seamless service properties of similar construction object designs. The authors considered features of the frame dome-shaped designs construction and assigned its pros and cons; the review of the technical investigation of one of the shopping centers was conducted with purpose of showing the consequences of inaccurate observance of the specified designs installation technology. Subject to facility technical investigation results, recommendations for the safety operation of dome support structures were given.

Keywords: steel designs, frame dome-shaped objects, frame dome-shaped roofs installation, technical investigation of frame dome-shaped roofs, spherical sheath imperfections

Mathematic modeling of the state of a thin round disk being heat and force affected is performed. In the central part of the disk the homogeneous field of temperatures is formed. Within the deformation theory of a perfect elasto-plastic solid the quadratic plasticity condition is chosen. The relationships between the radius of the disk, the temperature of the central part of the disk and the external pressure which defines the appearance of plastic zones have been established. For different values of external parameters of the model the stress vector hodograph and the plots of stresses and equivalent stresses have been introduced.

Keywords: mathematic modeling, an elastic-plastic solid, the plane-stress state, the deformation theory, thermo-elasto-plasticity, a high-speed rotating disk

The composition of fine-grained fiber-reinforced concrete using Portland cement, stone crushing waste, volcanic ash and basalt fiber are considered. It was revealed that with an increase in the ash content in cement, the compressive and flexural strength of fine-grained concrete decreases, and the water absorption increases. Without a significant reduction in the properties of fine concrete, you can enter no more than 10% of volcanic ash.It has been established that with an increase in the content of large fractions of aggregate, the compressive and flexural strength of fine-grained concrete increases as a result of a more compact arrangement of sand grains. The increase in the content of fine sand fractions reduces the strength characteristics of concrete, and increases water absorption. The dependence of the properties of fine-grained fiber-reinforced concrete on the method of mixing the mixture and molding products

Keywords: portland cement, stone-breaking wastes, volcanic ash, basalt fiber, grain size distribution, fine-grained fiber-reinforced concrete, bending strength and compression, method of mixture preparation, method of molding products

The article deals with the existing problems in our country, arising in the management of material resources in the process of construction of buildings and structures. The main problem in the material resources management system is that due to their late and incomplete delivery to the construction projects, there are significant downtime of working and construction machines and mechanisms. The don state technical University (DSTU) is developing an intelligent construction management system, which includes a method of planning and accounting for the movement of material resources to ensure synchronization of the processes of construction and installation works and their complete supply. The use of this technique allows to optimize the timing and volumes of supplies of material resources in accordance with a given technology of production operations and the simultaneous control of their inventory in the onsite warehouse

Keywords: organization of construction; economy of construction, production of building materials

The issue of urban infrastructure management and urban planning technology "Smart city". The possibility of urban areas’ modernization using this technology is being studied. Actual problems of management of "Smart cities" are considered. The possibility of a positive economic effect is being studied.

Keywords: organization of construction, construction’s economy, application of technology "Smart city", urban environment, city life cycle

The article is devoted to development of information modeling technologies in Russia. The possibilities of using 3D-models, their advantages and disadvantages are conserned.

Keywords: Information modeling, engineering, building operation, real estate life cycle

The purpose of the study is to develop a software – oriented algorithm for calculating flat rod systems with variable length modulus of elasticity. The object of study – a flat rod system, located in a single load, the elements of which are interfaced at the nodes rigidly or pivotally; the shape of the axes and the conditions of the support are set. A special finite element is developed on the basis of the finite element method in the form of a mixed method. To calculate the elements of the response matrix and the vector of freight coefficients, a numerical integration procedure is used. Examples of calculation of cantilever rods in two variants are given: with a variable length modulus of elasticity; and a rod having three, five and seven sections along the length made of different materials. The comparison with the results of other authors is given. A flat frame of four finite elements with variable modulus of elasticity is calculated. The results of solving the examples indicate the correct operation of the proposed algorithm. It is shown that the parameters of the stress-strain state of the structure can be adjusted by changing the properties of the material.

Keywords: mixed method, finite element, variable modulus of elasticity, response matrix

The calculations and assessment of the impact of the built dormitories on the design of the existing building in accordance with the requirements of SP 22.13330.2011 and techniques of the FEM program Plaxis 2012.01 (Build 8962)

Keywords: pile foundations, Plaxis program, Geology

This paper presents an analysis of domestic and international experience in the construction of modern non-rigid pavements. An assessment of existing structures on roads with high traffic volume; designated directory structure of non-rigid pavements, developed on the basis of the research.

Keywords: construction, non-rigid pavement, structural layers, the total number of rated load applications, traffic load class

The problem of formalizing the elastic line of a thin steel strip of great flexibility arose in the process of creating elastic elements with a nonlinear characteristic for use in various kinds of damping devices. Such elastic rods experience large displacements when the material operates within the elastic range, in particular when axial loading in the supercritical region, when the axial load exceeds the Euler force, but in the subcritical region the movements are not significant enough to obtain a regressive-progressive characteristic.The paper investigates the possibilities of softening the elastic characteristics under axial loading in the initial period by applying a rigid cantilever arm mounted on the end of the elastic rod with a vertical load applied to it. Simultaneously, the influence of the vertical force on the elastic characteristic of the circular trajectory is investigated. To formalize the stress-strain state of a thin steel plate of great flexibility, the method of elliptic parameters is applied. The resulting elastic characteristic actually has a regressive-progressive character. The results obtained using the ANSYS computation complex for a system with given geometric parameters correlate quite well with the theoretical dependences derived. It follows from the diagram that the eccentric compression of the elastic element forms a regressive part of the elastic characteristic, and the circular trajectory of the point of application of the vertical force forms a progressive section.

Keywords: elastic line, thin strip, greater flexibility, formalization, off-axis loading, elliptical parameters, regressive-progressive characteristic

Article contains features of planning of the house with a penthouse and garage, the main pluses and minuses of construction. In article advantage use of frame option of construction is described.

Keywords: penthouse, garage, planning, drawing, low construction, heat, soil, framework, floor, warming

In article there are considered the main questions with which reconstruction of buildings of preschool educational institutions is connected. Their main classifications and features are given. The review of questions is made and their list is formed.

Keywords: preschool educational institutions, dou, reconstruction problems, reconstruction, energy efficiency, actions, sanitation

An approach is proposed to determine the expected profitability level of production in making strategic decisions on stabilization and development of construction production at the enterprise. The prediction of achieving the profitability level (profit rate) at realization of new enterprise products is made using probabilistic methods. It is assumed that the actual profit rate is a random variable which is approximated by the standard β distribution, ie, the distribution of mathematical statistics for random variables limited on both sides by the maximum and minimum values of production. In the calculations are taken optimistic and pessimistic estimates of the rates of profit from the sale of construction products. Using the formula for calculating the mathematical expectation of the random variable that is characterized by the β distribution, we performed the forecast of profitability for the planned construction products that are new for the enterprise - three types of cottages with different technical parameters and comfort. The experts (specialists of construction organizations involved in manufacturing similar products) gave optimistic and pessimistic estimates of the expected rate of profit from the sale of cottages. The resulting expected profit rate was compared with the industry average territorial regulations and maximum value of risk assessment of not receiving the expected profit (a coefficient of variation). The calculated values allowed to make positive decisions on the construction and implementation of the selected types of cottages.

Keywords: enterprise strategy; complexes of strategic decision-making objectives; principles and methods of prediction; profitability of construction products; actual profit rate as a random variable; mathematical expectation of profit; optimistic and pessimistic e