Subject: mechanism for forming a strategy of management of the urban development of a small town. The problem of managing the urban development in the Russian Federation, taking into account ongoing social and economic reforms, is relevant and important. The main attention in solving the problem is given to the normative and legal regulation and maintenance of the state real estate cadastre. At present, there is a need to formulate a strategy for managing the town-planning activity of territorial entities, oriented on the rational use of the land resources. The small cities of Russia, in the majority of cases, are in a critical condition, but have a huge land potential, which is the economic basis for development of the small town and a source for financing the local budget. Research objectives: theoretical and methodological approaches to the formation of a strategy for urban planning in small towns. Materials and methods: method of aggregation of indicators, correlation analysis. Results: the article examines theoretical approaches to the concept and classification of the category “small town” and specifics of the formation of a strategy for development of territorial entities in Russia and abroad, identifies their advantages and disadvantages. An algorithm for the formation of a strategy for managing the urban development of a small town is proposed. The technique of determining the strategic type of a small town has been created and based on this technique the ranking of small towns by strategic types was carried out. On the example of one of the depressed cities of Trans-Baikal territory, recipes for getting it out of this state, for example, with the help of the regional construction complex, are suggested. Conclusions: the practical application of the new methodological approach to the formation of a strategy for managing town-planning activity will improve the efficiency of the use of land resources of a particular small town.

Subject: introduction of energy-efficient materials and decisions in the field of reconstruction is the factor influencing the reduction of heat losses. Use of such materials and decisions leads to considerable economy and improvement of heat insulation properties of the building. Research objectives: establish efficiency of application of methods of passive and active protection of buildings against heat losses and increase of energy-saving during reconstruction. Materials and methods: theoretical and methodological basis of the research was the scientific work of domestic and foreign scientists on the issues of energy efficiency management and introduction of energy-saving technologies at capital construction facilities and educational institutions. General scientific research methods (analysis, synthesis, generalization), comparison method, classification method were used during the research. Detailed thermograms of buildings, thermal imaging examinations, and monitoring of microclimate parameters were used. Results: modern approaches to the problem of energy-saving and provision of comfortable living conditions are investigated. The analysis of the use of active and passive methods to improve energy efficiency of buildings is carried out. Conclusions: improving the energy efficiency of buildings during reconstruction must be addressed comprehensively, taking into account measures aimed at increasing the effect of fuel and energy resource consumption.

Subject: due to a wide spread in construction practice of castellated beams with the rhomb-shaped perforation of the web, influence of parameters of such openings on beam’s deflections was investigated. Currently, in the Design Codes, both domestic and international, and also in Eurocode 3, the recommendations on determination of deflections of such beams are absent although they contain regulatory requirements. Research objectives: elaboration of analytical relationship, convenient for engineering calculations, for estimation of deflections of castellated beams with rhombic perforation of the web. Materials and methods: derivation of the deflection formula was carried out using one of the efficient methods for calculating deformations of perforated I-beams, based on the use of the theory of compound bars. Several numerical coefficients included in the expression for the stiffness coefficient of the elastic layer, formed by web-posts, were refined by means of finite element calculations. As a criterion for reliability of the analytical expression for deflections, the results of the finite element analysis of the beam, obtained with the ANSYS software complex, are used. Results: results of the study constitute the analytical relation for engineering calculations of deflections of castellated beams with the rhombic perforation of the web. The applicability of the proposed dependence to the calculation of deflections for beams with different shapes of rhombic perforation is verified by varying both the height of the openings and the width of the web-posts. In all cases, only the angle of inclination of the hexagonal sides, taken equal to 60°, remains fixed. An example of analysis of a perforated beam according to the method considered is given. For beams made by wasteless technology, when the width of the web-posts is equal to the horizontal side of the opening, for a rhomb-shaped perforation with a constant relative height of the openings, the total cut-out area remains practically unchanged for any width of the web-posts. A consequence of this is the weak influence of the relative width of the web-posts on deflections of beams with a fixed height of the openings. Conclusions: obtained engineering relationship will certainly be of practical interest to designers and can be recommended for including into the Design Codes of the Russian Federation.

Subject: transformation of relations between participants of investment and construction process and their documentation due to accelerated introduction of BIM modeling technology and its spread to the full lifecycle of the construction object. Research objectives: study of the composition and structure of the unified digital environment formed on the basis of technological platform of information modeling in construction, and analysis of the current state of affairs in this area in the Russian Federation; research of directions and mechanisms of transformation of the investment and construction process in terms of two currently used models of implementation of investment and construction projects: disintegrated procurement and integrated procurement models. Materials and methods: systematic approach, statistical and comparative analysis and method of expert assessments were used. Results: we have established a three-component composition of a unified digital environment in construction, including technological platform based on BIM-modeling technology, and in relation to a specific object - its information model; information and analytical systems associated with the BIM-model and providing its information content and updating; banks of normative, technical and methodological documentation. The following directions of investment and construction process transformation are identified: • early involvement of the construction contractor in the project; • extended application of integrated engineering models; • strengthening the role of unified state customers in the construction system for state needs; • implementation of the mechanism of documented partnership between the participants of investment and construction projects. Conclusions: the main direction of development of the investment and construction process in the digital environment, formed on the BIM technology platform, is the formation of mechanisms for in-depth cooperation of participants of investment and construction projects at all stages of the object’s lifecycle on the basis of a wide application of integrated engineering contracts, centralization of management in the system of public procurement and development of partnership mechanisms on the basis of multilateral partnership agreements made by the participants of investment and construction projects. Implementation of these mechanisms will require the appropriate development of regulatory, technical and methodological bases, as well as amendments to existing legislation related to public-private partnerships and public procurement.

Subject: economic development of housing and communal services is directly connected with implementation of the housing policy of the country, which is of great importance for the construction industry, the economy and the population. The deplorable state of utility networks and structures of resource-holding systems in Russia and Kazakhstan, inherited from the Soviet Union, basically did not meet the requirements of a sustainable and proper quality of provision of communal services. After acquiring independence in Russia and Kazakhstan, as in other post-Soviet countries, housing and communal services (housing and utilities) reform was implemented, massive privatization of the housing stock was carried out, which resulted in formation of a qualitatively new housing relations. At the same time, the past period has revealed certain disproportions in the development of housing relations, and as a result, a lot of problems have accumulated in the housing and communal sector that need to be addressed. In this regard, the relevance of the study aimed at conducting a comparative analysis of the development and the state of the housing and communal services of these countries is justified. The article assesses the current state and trends in the development of housing and communal services in Russia and Kazakhstan. This research was carried out within the framework of the scientific project APО05134552 «Economic evaluation of investment projects for modernization of housing and communal services of the Republic of Kazakhstan». Research objectives: conducting a comparative analysis of the development and condition of housing and communal services in Russia and Kazakhstan, and identifying problems related to the housing reform implemented in these countries and modernization of communal infrastructure. Materials and methods: the study used statistical data on the state of the housing stock and housing and communal services provided by the Federal Service for State Statistics of the Russian Federation and the Statistics Agency of the Ministry of National Economy of the Republic of Kazakhstan. This scientific study aimed at assessing the effectiveness of government programs implemented in the housing and communal services sector was based on the methods of analysis, induction, deduction, comparative and dialectical-logical approaches. Results: the assessment of the state of housing and communal services in Russia and Kazakhstan is given by the indicators assembled into the groups of the main sub-sectors of the housing and communal services - housing sub-sector and communal services sub-sector - for the 2010-2016 time period. Economic evaluation of the development of housing and communal services was based on the development of a set of quality indicators: 1) the proportion of emergency housing stock in the total area of the entire housing stock; 2) provision of the housing stock with the types of amenities (water supply, water disposal, heating, gas or electric stoves); 3) the level of housing provision for population; 4) accident rate in the networks; 5) loss of resources in the networks (water and heat). Conclusions: in the course of the study, it became possible to identify problematic issues that hinder the more successful development of the housing and communal sector in the analyzed countries. The conducted studies justify the need for sectoral reforms and an integrated system for assessing the development of housing and communal services in accordance with strategic policy and targeted state programs.

Subject: the deterioration and technical condition of water supply and drainage pipelines in most of Russia’s settlements, the limitation of material resources for their restoration and renovation in conditions of housing and communal services reform, require a scientifically grounded approach to the reconstruction and modernization of these systems [1-4]. To solve these problems, the Government of the Russian Federation approved and introduced normative documents1, 2. According to them, the development of centralized water supply and water disposal systems is carried out only in accordance with the general schemes of these systems3. As part of these schemes, it is necessary to develop an electronic model of a centralized water supply and disposal system for an objective assessment of the impact of activities aimed at optimizing their work [5]. The algorithm for constructing and calibrating the electronic model of the city’s water supply system is the subject of this study. Research objectives: development of a methodology for constructing electronic models and algorithms of calibrations which are applicable to the Russian Zulu software. Materials and methods: for an objective assessment of the impact of long-term measures aimed at improving the operation of the water supply network, as well as the development of the city’s water supply system, we use modeling along with the implementation of an adequate electronic model. The adequacy of the electronic model is achieved via its calibration [6]. The object of the research is the water supply system of Minsk and Salavat in the development of electronic models for realization of their development and reconstruction directions. Results: based on the experience of implementation of a number of water supply systems (Ufa, Irkutsk, Penza, Orenburg, Tyumen, Salavat, Minsk), a methodology for constructing and calibrating electronic models was developed; the algorithms applicable to the Russian Zulu software and necessary for construction of models were also developed. Conclusions: the results of the work are implemented on a number of water supply systems in the cities of Russia and can be recommended for application of information technologies in electronic model realization, the assessment and analysis of the functioning of water supply systems and the optimization of their operation.

Subject: the article contains the description and the possibility of using the Parzen-Rosenblatt window method which belongs to the methods of non-parametric statistics for estimation of empirical density of distribution of particles for disperse materials - compacted microsilica (silica fume). As a dispersed material, the compacted silica fume is considered. Microsilica is a byproduct of the metallurgical industry and is used as a pozzolanic additive for the manufacture of various types of concrete. The compacted silica fume consists of spherical particle-clusters formed of individual silica fume particles. Research objectives: description and implementation of the Parzen-Rosenblatt window method for obtaining empirical density distribution function for the diameter of particles of compacted silica fume; comparison of the histogram method with the Parzen-Rosenblatt window method in estimating the distribution of the diameter of particles of compacted silica fume. Materials and methods: the Gaussian weight (kernel) functions are used to implement the Parzen-Rosenblatt window method. The Sheather-Jones plug-in method is used to find the optimal bandwidth of the kernel functions. In the Sheather-Jones method, the non-linear equation for finding the optimal bandwidth is solved numerically using the Newton’s method. Implementation of the methods is performed in the programming language of the numerical computing environment Matlab. Results: the Parzen-Rosenblatt window method was described and implemented, and by implementing this method, the estimate of empirical density of distribution of the diameter of particles for compacted silica fume was obtained. A comparison of the Parzen-Rosenblatt window method and the histogram method is also given, for example, by reconstructing the density distribution of the diameter of particles of compacted silica fume. Conclusions: application of the Parzen-Rosenblatt window method allows us to solve the problems that arise when using the methods of parametric statistics and the histogram method in estimating the empirical distribution density of particles of disperse materials. In particular, there is no need to assign unknown statistics for the methods of parametric statistics and determine the number of intervals for the histogram method. Density distributions obtained by the Parzen-Rosenblatt window method can be used for statistical modeling of physical and mechanical properties of building materials.

The paper discusses the international experience of 3D-printing technology implementation in construction. The analysis of existing technological solutions of domestic and foreign organizations such as WinSun, AMT-SPETSAVIA, StroyBot, BetAbram, Contour Crafting Corp., ApisCor, Loughborough University, CyBe Construction, Batiprint3D, MIT Media Lab and DUS Architects is performed. The advantages and disadvantages of different approaches to performing layer-by-layer construction of building structures are shown. Subject: the analysis of products and structures made of cement concretes produced by the layer-by-layer extrusion method is carried out in this paper. Materials and methods: in this work we use a complex of general scientific logical methods of research based on a theoretical analysis of technological solutions presented in the scientific and technical literature, information resources from developers and the media recourses, including patents, scientific articles and scientific reports. Results: the existing technological solutions of 3D-printing in construction are analyzed, their advantages and disadvantages are shown, and the problems of technology development are formulated. It is established that the main material for 3D-printing is the cement heavyweight fine-grained concrete, which includes a filler of size no more than 4 mm, mineral additives, microfiber, anti-shrinkage chemical additives and setting time regulators. The concrete has an average density of 2100...2200 kg/m3 and a compressive strength of 25...50 MPa. It was found that the non-optimal rheological properties of mixtures and the absence of solutions to improve the operational properties of concrete do not allow us to expand the functionality of printed elements beyond enclosing structures or permanent formwork and fully realize the potential of 3D printing. Conclusions: the process of extrusion for building construction must be based on general principles and requirements to materials and structures. The search of the complex technological solutions on the each stage of construction is a promising task for the development of 3D-printing in construction. It is necessary to formulate general requirements to materials used in concrete 3D-printing and develop universal prescription solutions that allow us to simultaneously control the viscosity and flow of the mixture during extrusion and also create the required physical, mechanical and operational properties. Key words: 3D-technology, 3D-printing, contour construction, rapid prototyping, materials for 3D-printing, extrusion, layer-by-layer design construction, 3D-printer, mixture for 3D-printing, building ink, high-strength concretes, dry building mixtures Acknowledgements: The work was carried out within the framework of the agreement No. 14.583.21.0072 on granting awards for implementation of the federal target program “Research and development in priority directions of development of the scientific and technological complex of Russia for 2014-2020” (project identifier RFMEFI58318X0072) with the financial support from the Ministry of Education and Science of the Russian Federation.

Subject: durability of coating based on silicate paints. The article substantiates the prerequisites for using sol-silicate paints for finishing exterior walls of buildings. Sol-silicate paints obtained by mixing the sol of silicic acid with sodium liquid glass are considered. The features of formation of the structure of polysilicate solutions have been studied. Materials and methods: silicate and sol silicate paints. Polysilicate solutions were obtained by the interaction of stabilized solutions of colloidal silica (sols) with aqueous solutions of alkaline silicates (liquid glasses). The sol of the silicic acid Nanosil 20 and Nanosil 30 was used. For determining the long-term strength, samples measuring 10 ? 30 mm were cut from a free paint and varnish film. To evaluate the parameters of the activation energy, a series of experiments were performed to measure the longevity at various constant temperatures and stresses. Results: a higher value of the activation energy and a lower value of the structure-sensitive factor for coatings based on a polysilicate solution indicate their great strength and durability. When coatings are wetted, a decrease in the activation energy of destruction is observed, and it is more significant in coatings based on potassium liquid glass, and an increase in the structure-sensitive coefficient is also observed. Conclusions: studies have been carried out to evaluate the long-term strength of coatings based on silicate paints. It has been established that the activation energy of destruction of coatings based on polysilicate solutions is higher than the activation energy of destruction of coatings based on liquid glass. The values of the structure-sensitive factor are calculated. The results of the conducted studies and calculations indicate a higher resistance of coatings based on the potassium polysilicate solution.

One of the main task for engineer during design of hydraulic engineering structures is an accurate calculation of weir profiles in open streams. Modern technologies make it possible to obtain building materials that allow realization of the given shapes of the surface of dam structures. To increase the reliability of building structures elements of spillway vacuum-free dams, there is a need to improve methods of calculating configuration of the drainage surface in the area where it meets the apron. Subject: methods for calculating configuration of the drainage surface in the area where it connects with the apron. Research objectives: improvement of methods for calculating configuration of the drainage surface in the area where it meets the apron. Materials and methods: the method proposed in this article is based on the possibility of refinement of analytical definitions of the conjugation radius with allowance for the influence of the losses of the total mechanical energy of the falling streams due to the created turbulent stresses with the critical depths corresponding to the minimum energy on the intensity of dynamic effects of the flows onto the structures of spillway’s coupling elements. Results: the method of refined calculation of the circumference radius of the contour end section of vacuum-free weir of practical profile is proposed. Conclusion: the approach proposed in this research work can be used in hydrotechnical construction.