Proceedings of CEE 2019

In this paper results of stiffness iterative determination technique while torsion the reinforced concrete rod elements considering concrete nonlinear properties is given. The section of the element is divided into several rectangular elements. The shearing torsions at each iteration step are determined by the distribution of torsions, which magnitude is higher than the limit, over the elements where the torsions are in the elastic area. An algorithm for obtaining points on the “Torque moment is relative twisting angle” diagram of a reinforced concrete rod elements is given. Its advantage from a similar technique is that shear torsions are determined directly from the concrete shear diagram, and not according to the formulas of the elasticity theory. The above algorithm enables to calculate reinforced concrete rod elements using any concrete shear diagrams obtained both experimentally and theoretically, as well as elements of any cross-section. Limiting torsions are determined directly from the concrete shear diagram.

Materials obtained during archaeological excavations on Wysoka Gorka in Cholm (today Chełm in Poland), in the area of king Daniel’s 13th century residential complex, have been subject to examination. They come in the forms of bricks and glazed tiles, as well as sizeable shapeless and purposeless accumulations indicating post-manufacturing remains. The materials are white, green and multi-colored. They refer to Halytsian alabasters and green glauconite from Cholm which were originally used there. The examination of white materials was performed. They were diagnosed by means of SEM microscope and X-ray diffraction. Furthermore, a micro area chemical analysis was conducted by means of SEM microscope with EDS module. The conducted examination indicated that the materials in question were manufactured using other than ceramic technologies, but similar to the ones used to produce silicate materials nowadays. As raw materials, chalk and biogenic silica obtained from a horsetail were used. The petrification procedure was conducted in hydrothermal conditions. As a result a material structurally similar to marble was obtained. The successful production of the materials translated into possibility of the implementation of the ideological assumptions of the structures having been constructed under the explicit influence of the style of the 13th century Tuscany School.

Most important parameter of serviceability limit state (SLS) for reinforced concrete (RC) beams is crack resistance. These include width of crack opening, cracking distribution, load at which is achieved limit and maximum width of crack opening. This is especially important for shear resistance. In this article, new data of crack resistance of rectangular RC beams are described. Changing parameters were shear span (acquiring values 1, 1.5, 2) and strengthening with FRCM (Fiber Reinforced Concrete Matrix) system in the supporting area. Eight samples for experimental researches were carried out: six once from them without strengthening but with different shear span and two once with composite system. Using the limit width of the crack opening as criteria of exhaustion of the bearing capacity can conclude that remains about 19–26% of load caring capacity before the danger of shear failure of the beam. When the shear span decreases on the 25% the maximum width of the crack opening decreases only on the 7% and on the 40$ when shear span decreased by 50%. External strengthening system reduced maximum crack opening on the 43%: from 0.75 to 0.43 mm and values exceed limit insignificant.

Nowadays steel plate reinforced concrete beams are widely used in construction around the world. The use of such structures allows high-quality welding, saving materials’ saving and avoiding complex joints.Decking structures contain solid or lattice steel beams, on which the flooring of steel profiled sheets is laid, which simultaneously acts as both formwork and the lower stretched rebar for monolithic concrete. After analysing the special literature and practical issues of steel plate reinforced concrete structures, it could be concluded that such structures have increased bearing capacity and cracking resistance, as well as more economical characteristics comparing with reinforced concrete structures. The high-strength steels’ usage in steel-concrete structures makes it possible to achieve even greater savings. Combination of the properties of steel plate reinforced concrete beams reinforced with S275 steel plates with the strength of high-strength rod reinforcement of class A1000 ensures the possibility to achieve additional reduction of metal consumption with simultaneous observance of permissible strain and crack resistance requirements.

Theoretical and experimental investigations of the studies of the mechanism of a penetrative action of waterproofing compositions have been carried out. It was theoretically justified that the mechanism of penetration of the salts of the complex chemical additive of analyzed mixture into the concrete (mortar) of the structure carried out according to the diffusion mechanism. The diffusion of the salts of the complex chemical additive into the concrete with different porosity was calculated theoretically. For the water-saturated noncapillary pores after two hours diffusion depth attains 9 mm, and after three hours it is already 14 mm; for the loose concrete it occurs at a slower rate and after 1 week its depth attains 3 mm; for the dense concrete after 2 weeks it is within 0.2 mm. It was experimentally confirmed that the salts of the complex chemical additive included into dry Portland cement-based mixtures penetrate the loose concrete with the water resistant less than W2 the depth of 5 to 10 mm, and it results in the colmatation of the porous space with the crystal hydrates of AFm- and AFt-phases at the same depth.

The article is devoted to the problem of Odesa historical buildings’ preservation. According to the Law of Ukraine about Protection of the Cultural Heritage (2000), we can call the Vorontsov Lighthouse, National Academic Theatre of Opera & Ballet and the Factory of sparkling wines the objects of historical and cultural heritage of Odesa. The article presents the results of the preservation monitoring (based on the reports) of these buildings. Reports were performed by employees of the Odessa State Academy of Civil Engineering and Architecture during 1990–2019. A huge number of negative factors had an impact on historical buildings. One of the most important structures of the building is its underground part. The variability of the soil is one of the main causes of structural damage. Foundations’ settlement monitoring and control of the structures durability with non-destructive and micro-invasive testing methods are being conducted. The article describes the historical facts of building maintenance, which explain the reasons for the appearance of deformations.

Cylindrical nozzles each of which has a lateral orthogonal inlet of fluid into it we recommend to apply in pressure distributive pipelines. By means of rotating these nozzles about their longitudinal axes, we can change the values of the angles $$ \beta $$ between the direction of the flow of fluid inside the distribution pipeline and the direction of the inflowing into the nozzle stream. The coefficient μ of flow rate through the nozzle with lateral orthogonal inlet is a function of the angle β. By means of changing the angles β, we regulate the non-uniformity of fluid dispensation from the pipeline along the path. It is experimentally established that the values of the coefficient μ for such nozzles depend on the angle β, on the squared ratio $$ (d/D)^{2} $$ of the cross-section area of the nozzle d to the cross-section area of the distributive pipeline D, as well as on Reynolds’ criterion Re which is calculated for the water stream in the nozzle. As operating fluid, we used water. The angles β were assigned the following values: 0, 45, 90, 135, and 180°. In the experiments, we used the distributive pipelines whose diameters D were equal to 11.28; 16.13; 20.18; 26.01 mm. The diameters d of the nozzles were 4.83; 6.01; 8.02; 8.99 mm. ratios (d/D)2 of cross-section areas were 0.0887; 0.119; 0.158; 0.183; 0.251. The greatest values of the coefficient μ of flow rate of the nozzles were obtained for β = 0°; the least for β = 90°. The greatest range of regulation of flow capacity (throughput) of nozzles has been obtained for (d/D)2 = 0.251; the values of μ variated by 23%.

The presence of inorganic pollutants such as heavy metal ions in industrial effluents is a worldwide issue for the environment. These pollutants are not only hazardous in exceeding concentrations but due to the property of accumulation in living organisms it is urgent to look for the plausible solutions for their reducing and treatment from wastewaters.In this study, cherry wooden sawdust were used for removal Cu(II), Zn(II) and Fe(II) ions from model solutions with using the static and kinetic adsorption experiments. Infrared spectrometry of cherry wooden sawdust confirmed the presence of the functional groups which correspond with hemicelluloses, cellulose and lignin. At static adsorption was achieved approximately of 70% efficiency for all treated model solutions that is comparable with the efficiency of the adsorption processes reached after 5 min at kinetic experiments. The highest efficiency of Fe(II) removal (89%) was observed after 120 min of intensively shaking at frequency of 100 rpm. The mechanism of ion exchange on the beginning adsorption process by the changes of pH values was indicated.

This article describes the tests of pressure distribution on a bridge abutment, generated by the backfill made of recycled car tyres compressed in the form of bales with interfaces of medium sands and a buffer layer with tyre shreds or gravel. The backfill pressure distribution was measured continuously over a period of three months using pressure sensors. Static and dynamic load tests of abutment were conducted. The results of pressure field measurements were compared with the analytical calculations from medium sand backfilling according to the EC7. Based on the field measurements, the reduction of pressure on the bridge abutment was found if the tyre bales had been used, in comparison with the conventional backfilling of sand or gravel. The article also describes the first Polish application of abutment backfill from the tyre bales in a road bridge.

This article investigates possibilities and expediency of transformation of existing Ukrainian District Heating Systems (DH-UA) into the modern district heating of the 4th Generation (4G-DH). Three research problems were tasked to be solved. The first concerns studying the current state of existing DH-UA. The second one was connected with the analysis of the requirements to the last generation of district heating systems that begin to spread in the EU. The third problem was searching of ways to transform of DH-UA to 4G-DH. The survey of the current state of Ukrainian heating networks shows that existing systems DH UA correspond to 2G-DH–3G-DH levels. These systems from one hand are on the critically low technical level and on the other hand have the great potentials of improvements of energetic, economic and ecological characteristics of consumption of primary energy sources in Ukraine. The analysis of the opportunities, prospects and pace of convergence of existing DH-UA to the requirements of the last generation of European DH systems was carried out. Implementation of 4G-DH as an energy-efficient, low carbon, competitive heating system is a key issue for reforming the housing and utilities sector in Ukraine.

The article deals with the influence of various aggregate compositions used to semi-dry concrete on some properties of hardened concrete. The concrete mix compositions were aimed at using in precast production of manholes and pipes for sewerage systems. Five fractions of aggregate (0/1, 0/2, 0/4, 2/4 and 4/8, respectively) were used, while grains of fraction 0/1 had rounded shape and fractions 0/2 and 0/4 were pre-crushed. Fraction 2/4 and 4/8 included half of rounded as well as half of crushed grains. Concrete mix compositions also varied within the content of cement paste according to experiences from production plant. The concrete surface (from −2 to 1), density of hardened concrete in saturated and dried state (from 2265 to 2416 and from 2142 to 2336 kg.m−3), splitting strength (from 4.9 to 6.2 MPa) and water absorption (from 3.4 to 5.8 wt%) were observed.

The article is devoted to the deformation definition of the proposed acrylic modified glued compositions for the development of reliable, high-strength steel-concrete joints, using the Lode-Nadai coefficient, which determines the stress condition form of the medium. The numerical calculation, according to the principles of materials energy rationalization using the Vasil’kov-Shmukler criterion, is carried out, which testifies that the proposed acrylic compositions for the without anchor joint have a substantial structural strength margin (for the stress – at 6 times, for the energy of deformation – at 36 times). Diagrams of adhesive material deformation (σ-ε diagrams) under the influence of corresponding exertional efforts (tension, compression, shear) were constructed. According to the deformation diagrams, linear deformations and the boundary value of the deformation energy density were calculated. The obtained results of experimental research data can be used for attachment joints projecting and industrial technological lines development, as well as for further improvement of polymeric adhesive materials, widely applied in industrial and civil engineering.

The work is aimed at studying and solving the problems of vacuum-condensation spraying for titanium nitride. The nature of the work is applicable because the proposed advanced technology can be applied to the production of any parts with coating. The applied technology will reduce a cost of manufacturing wear-resistant parts and therefore tends to save energy. The promise of the advanced vacuum-condensation spray technology is due to a decrease in the number of defects on the surface of the spray product. The novelty of the work is to improve the coating properties by reducing the defects of the structure.

The chemical modification of oxidized bitumen BND 70/100 by formaldehyde, or rather its aqueous solution, formalin, was carried out for use in hot asphalt pavement technologies. The chemical modification conditions of bituminous binder by formaldehyde are given. There is shown considerably increases of the heat capacity (softening point) and adhesion properties (adhesion to glass) in the chemical modification process of oxidized bitumen by formaldehyde. The adhesion determining methods of binder with granite crushed stone and glass plates as variants of adhesive ability estimation of bitumen are given. It has been established that the modification by formalin in the amount of 10% by weight dramatically reduces the bitumen viscosity, so it showed necessary to carefully monitor the source bitumen and formalin ratio content during the modification. A hot dense fine-grained asphalt mix was selected. The influence of modified bitumen on physical and mechanical properties of asphalt concrete, such as water saturation, border compressive strength at 20 and 50 °C and the long-term water resistance coefficient after 15 days.

It has been established that the qualitative parameters of the non-uniformity of the radial fan’s discharge flow are energy parameters such as coefficients of kinetic energy and the amount of motion. Compared with the ratio of maximum velocity to the average one, in the case of backflows, the specified indicators reflect the flow characteristic throughout its section. It has been proposed to determine the pressure loss in the diffusers located behind the radial fan, that is, with the non-uniform distribution of the velocities at the inlet, and with the uniform distribution of the velocities at the outlet, using the change in the kinetic energy coefficient.

The article shows analysis of the utilization of plastics and method for their identification in facilities in Subcarpathian region. Paper presents types of plastics which have been used in the most facilities. Single-layered pipes from homogeneous plastics as polyethylene or polypropylene were applied in the past. Now pipes made of polypropylene are used mainly in external sewage system or domestic waste disposal system. In installation of heating system polybutene for example wall heating are also widely used. In relation to other plastics used in this country for installation polybutene is not the most important material. In Subcarpathian region exist landfills which do not carry out waste compaction. This landfills are conventional, compacted and where waste are compressing by bulldozers. Identification of plastic have been mostly executed in specialist laboratory located in industrial plants. However there is necessity of carry out specific analyses in terms of its quantity and quality because they are still rare.

The aim of this paper is the creation of engineering method of inclined sections of beam structures calculation under the action of cyclic loads, that takes into account the concrete and reinforcement fatigue strength. Methods of research are key expressions determining the endurance limits of concrete, longitudinal reinforcement, and anchoring longitudinal reinforcement, which based on the real physical and calculated models of beam structures inclined sections work. The results of work links with the creation of expressions determining the boundary forces that can be carried out by structural element under the action of cyclic loading. Scientific novelty and practical significance is that presented engineering method takes into account the change of stress-strain state of span reinforced concrete structures at their repeated load, as well as, a change of strength properties of the concrete, reinforcement and their clutch at the moment t, and can be used on all range of strength characteristics of materials change- from low-cycle repeated, to repeated cycle load.

Natural daylight is a vital element in our life and it is very important at work. Providing natural daylight into the working environment is one of fundamental importance for the comfort, efficiency and safety for the people in that environment. This paper deals with visual comfort evaluation in administrative building, in office spaces. The human eye is able to perceive light at the moment it occurs. It cannot accumulate or move it in the human body for future use. Light perception is a complex process that is described by photometric quantities. It is important to work with variables in the theory and practice of daylight, enabling the creation of a healthy and safe environment for people to work and relax, and for the energy efficient management of buildings. One case study is presented in this contribution. It was measured in real situation an also calculated by the Radiance simulation program and Velux Daylight Visualizer.

The purpose of the work is to create an operation life-cycle model of the “building -base” system. In this model, the numerical reliability parameter is taken as the criterion of the system technical state. This serves as a quantitative integral estimation of the system technical state and risk. The reliability calculation method on the proposed life cycle model is proposed. The process of a system degradation during a life cycle is described by a nonlinear algebraic function. The result is the determination of the reliability lower values in the “building-base” system, taking into account the degraded system state and the safety characteristic β. The scientific novelty of the proposed methodology is that the model takes into account the construction geotechnical conditions, the system maintenance conditions, the system design lifetime. The practical significance of the proposed model is seen in the possibility to objectively determine the system operational state, depending on the calculation reliability.

The main goal of the research is to develop a calculation model for determining the residual bearing capacity of compressed stone elements of damaged cross-section. In the laboratory, 15 prototypes with pre-modeled damage were manufactured and tested. From the selected variation factors most affect the carrying capacity proved parameters characterizing element damage eccentricity affects secondary. According to the estimates of the experimental statistical model and single-factor local fields, the depth of damage in the cross section of the column has the greatest impact on the bearing capacity. A calculation model was created to determine the residual bearing capacity of damaged structures of rectangular cross section and the height of the compressed zone (x) and the area of the compressed zone (Ac). At its core, the model is based on the basic assumptions of existing building codes. The article presents two generalized types of damages according to the type of shape: direct damage - when the inclination angle of the damage front is zero and oblique damage - when the inclination angle of the damage front is not zero.

When reconstructing existing school buildings and building new buildings, great emphasis is placed on increasing their thermal resistance and reducing air tightness. The consequence of these modifications is the reduction of heat flow through the building structure, as well as minimization of uncontrolled ventilation by infiltration through building leaks. According to various studies conducted in the world, it can be said that the exchange of used air for fresh air has a huge impact on the mood of students in the classroom. As part of a research stay at the Lviv Polytechnic, measurements were made in the classroom to determine the air quality during the teaching. The classroom was selected in which measuring instruments were installed for measuring carbon dioxide (CO2) concentration and air temperature. During the measurements didactic classes took place in the classroom. In addition to the measurement of indoor air parameters, a subjective assessment of air quality was carried out using questionnaires. The students filled out the indoor air quality questionnaire at the beginning of their stay in the auditorium at the end of their stay. An assessment of air quality was carried out based on the measured air parameters and questionnaire ratings in the selected classroom.

In the article the characteristic features of natural light are analyzed and on their basis technological methods of designing functional artificial lighting, approximated to the properties of natural light, are determined. In the process of research such methods as analysis, synthesis, generalization, and scientific observation were applied. The consideration of natural light properties was based on its following characteristic features – light intensity, colour temperature, peculiarities of light distribution, dynamics, cyclicity. The research has both theoretical and practical value when forming design proposals and creating appropriate light scenes and scenarios. Consequently, a conceptual list of technological methods of functional artificial lighting has been formed as a part of the design of light environment approximated to natural lighting. These methods include imitation only of that part of the diurnal daylight lighting scenario when the intensity of light is sufficient, and the light distribution has a positive emotional and psychological influence; combination of diffused and direct light and the use of different colour temperature sources for them; coordination of the dynamics of the functional artificial lighting system with a 24-h diurnal cycle, accompanied by transitions between light scenes that are inconspicuous in the course of short-time observation.

The article deals with an analysis of the popular existing solar heating systems and the main directions of modern research on air heating solar collectors. The analysis has made it possible to outline the purpose of the research, namely, to study the nature of the distribution, as well as the rate of distribution of heated air mass in the room heated by the presented solar air heater with turbulators flow. Based on computer simulation and experimental research, it has been found that a thermosiphon air solar collector is capable of providing certain comfortable indoor climate parameters for a person, namely temperature and air flow velocity. In addition, the air solar heating system with a phase-change battery has been presented. The main difference of this system is the availability of the heat-accumulating coating installed in the air channel in the form of a matrix with segments filled with saturated solution of Glauber salt.

Rotation capacity plays a very important role in an advanced analysis of steel frames, especially in plastic design of structures. In current version of Eurocode 1993-1-8 there is a lack of design procedure to calculate rotation capacity of steel structure joints. In the paper the calculation procedure of the rotation capacity for stiffened bolted end-plate beam-to-column connections has been proposed. Because of many variables influencing rotation capacity of such joint, theory of experimental design was used. The analysis was performed with the use of finite element method, based on the numerical experiment plan. The determination of maximal rotation angle was carried out with the use of regression analysis. The main variables analyzed in parametric study were: pitch of the bolt “w” (120–180 mm), the distance between the bolt axis and the beam upper edge cg1 (50–90 mm) and the thickness of the end-plate tp (10–20 mm). Obtained simple formula can be used in everyday design practice to estimate rotation capacity of the joint.

The results of an experimental study on crack-resistance of large scale compressed-bent reinforced concrete columns strengthened under initial load are represented in this paper. Structural performance of unstrengthened reference samples and jacketed samples under initial load of 30%, 50%, 70% and 90% of the bearing capacity of the reference samples was investigated. During the tests of the columns cracks pattern along the length of the columns, cracks length and width development were observed and recorded. Crack width vs Load graphs were plotted for the analysis of cracks development. Crack width at each loading stage was recorded to determine the critical crack. The load Nw when the critical crack reached the width of wmax = 0.3 mm (according to Eurocode-2: Design of Concrete Structures) was considered as a loss of serviceability of the column. Analyzing the increase of columns serviceability after reinforced concrete jacketing the conclusion was made that higher load level during strengthening results in the lover strengthening effect. The maximum increase in serviceability of the columns considering the ultimate crack width was achieved when the sample was jacketed without any initial loading and the minimum - for the samples jacketed under the load of 90% of their bearing capacity.

At the time of reconstruction of edifice, it often appears a need in researches of bearing capacity for prefabricated reinforced concrete crane beams for the purpose of their exploitation in future. And also the designers look into possibility of installation modern bridge cranes with technical characteristics, which are different from foreseen or existing bridge cranes for establishment on these constructions. Different mark of cranes by equal weight-bearing capacity during the exploitation cause appearance of bending moments and shear in reinforced concrete crane beams, the values of which differ depending on technical characteristics of cranes. The maximum load of the wheel on the crane and the distance between the wheel’s axes are important characteristics of hoisting cranes during researches of bearing capacity for prefabricated reinforced concrete crane beams. Accordingly, the exploitation of reinforced concrete crane beams is possible only after research of bearing capacity for these constructions by means of plotting of bending moment diagram and shear diagram, and moreover analysis of changing for deflected mode of these constructions.

It was shown that a significant reduction of CO2 emissions in construction is achieved through the using of composite cements with a lower clinker factor. A quaternary composite cements (clinker factor - 50%) containing granulated blast furnace slag, natural zeolite and limestone has been presented. The composition and particle size distribution of the constituents are optimized by the incremental coefficient of the surface activity. Synergistic combination of fine mineral additives and fillers in composite cements ensures the formation of dense microstructure of paste. It is shown that the addition of microsilica (MS) and polycarboxylate ether (PCE) admixtures ensures the production of higher strength cements. In order to accelerate the process of hydration of cement at an early age, the suspension of the C-S-H (X-Seed) nanoparticles was introduced. The effectiveness of a MS – C-S-H – PCE admixture in the early strength development of composite cement with zeolite was investigated. It has been found that the addition of MS – C-S-H – PCE significantly increases the compressive strength of cement mortar, particularly at 12–24 h of hydration. XRD and SEM measurements confirm that the hydration of composite cement is greatly accelerated. Based on the obtained results, high quality eco-efficient composite cements with high early strength can be produced.

The growing need of durability enhancement for road bridge decks has recently caused the big impulse for research on a new, durable, lightweight and easy to handle bridge decks, made of advanced materials, f.e. FRP (fibre reinforced polymers). Therefore, in the frame of UE 7FP project PANTURA, three structural solutions of sandwich FRP bridge deck have been elaborated, fabricated and tested under static load. The panels are planned to form a deck slab in a vehicular girder bridge. The span of 2.4 m in a simply supported system was adopted as a typical span length. After the panels were manufactured by the vacuum assisted resin transfer molding method (VARTM) they were tested in the laboratory under static load. At the same time, a numerical model based on the finite element method was created to analyse panels’ behaviour under the test load. The paper contains a short description of the experiment procedure, FE analysis and a comparison of results obtained from tests with results obtained by means of numerical simulations.

The structures of shaft headgears belong to the high responsibility class of structures, which have a requirement regulatory - monitoring equipment for technical condition. Due with the dynamic tone of operational loads, for the construction of shaft headgears is relevant to create vibration monitoring systems.In the experimental researches of dynamic behavior of shaft headgears structures, were applied measuring method of vibration parameters by vibration transducers. Long-term observations of peak values of vibration velocity amplitudes were statistically processed and established by distribution laws of their random variables.Comparison of the obtained amplitude-frequency characteristics of general vibration structures with the results of modal analysis was made.In this article a rational scheme of the vibration transducer location in the upper part of the structures is proposed. Based on long-term statistical data analysis observations of the peak values of the vibration amplitudes the criterion for determining the limiting values of the vibration speed amplitude is formulated. But exceeding of that is a diagnostic sign of unsatisfactory technical condition of the structure. That are under condition of the spectrum deviation of own frequencies from the reference.The concept of vibration monitoring of shaft headgears structures is formulated, which is based on the comparison of constantly measured vibration speed amplitude with boundary values, and also on the control of the spectrum of the own frequencies oscillations.

The advantages of Displacement Ventilation systems as an energy-efficient way of air distribution are indicated. The task Displacement Ventilation systems is to provide normative parameters of the microclimate in the working area. For the most part, this task cannot be solved without uniform air distribution directly to the working area, for which source perforated low-speed air distributors are used. The characteristics of air distribution devices of Displacement Ventilation systems is are presented. There is no analytical justification for the design solutions of these devices. The necessity of analytical study of aerodynamic processes in the body of the proposed air distribution device is indicated, and it is also advisable to obtain a criterion equation of similarity for dissemination of the results of experiments on similar, but not yet studied objects. To obtain generalized dependencies, it is suggested to use the theory of similarity. The scheme of the experimental installation, the general scheme of the air distributing device, and the schemes of structures of the investigated air distributor are presented. The results of the research are presented. As a result of mathematical description of aerodynamic processes in the case of a low-speed air distributor, a criterial equation of similarity was obtained.

In the article, theoretical researching of the influence of damage in the compressed area in bending reinforced concrete elements is presented. The main attention is paid to the comparison of the impacting two factors on the bearing capacity: level of loading and the loss of the cover in the compressed area. In the first step, carried the formation of a matrix of the dependence impact of each factor on the bearing capacity with the subsequent determination of coefficient of influence and the formation of the regression equation. Analyzing the regression equation, obtained results of the impact of each factors, and their interaction, on the bearing capacity of the element. Second step is modeling of the experiment research using software “Femap with NX Nastran”. Thereafter, there was created a table of the distribution factors and their combinations with the indications of their impact on the carrying capacity of the model. It is possible to concluding, that the main factor is the initial level of loading, when the bending reinforced concrete beams received damages. The obtained results show the relevance and expediency of conducting experiments with the aim of determination of the residual bearing capacity in damaged reinforced concrete elements.

This paper deals with the study of the minimum required level of reliability of the steel capacities for grain storage and products of its processing, which should be ensured on the terms of economic expediency. This indicator is determined from the stochastic calculation of the construction, considering the stochastic nature of external influences and strength indexes of steel. The storage capacities are considered as constructions with exclusively economic responsibility. The calculation algorithm is based on the definition of the construction risk indicator. Graphically, it is expressed on the basis of the probability of failure-free operation or geometric characteristics of the cross-section. Considering the direct dependence of the element cost and its cross-sectional area, on the basis of a minimum of the risk function, it was obtained the formula of economic loss. It depends on the optimal probability of failure and the coefficient of the load variation. For steel storage capacities the generalized effort is schematized by two distribution laws: the normal one, which is used to describe the pressure of the bulk material on the body walls of the storage capacity, and the double exponential distribution of Humbel, which is used to describe the maximums of the snow and wind loads.

Clean atmospheric air is one of the most necessary conditions of qualify life of the population and for saving the healthy environment for future generations. In my opinion, the best way to provide a high level of life in every area and field of study is an exchange of experience. So the comparison of atmospheric air quality in Poltava and Leipzig is a great opportunity to find out what is done and what can be improved. With this goal, it is necessary not only compare the state of the air but also discuss which methods are used for monitoring its quality and what can be changed to implement maximum effectiveness in using time, sources and money. Every step should also provide an environment saving tendency. The comparing of a meteorological situation in Poltava and Leipzig is presented. Also, the results of the calculation of atmospheric pollution indexes are provided. There is some difference in limit values of pollutants in atmospheric air in Ukraine and the European Union. Data about stationary observation posts of ambient air is also included. There is a discussion of air pollution level in Leipzig and its connection to the meteorological conditions.

In this work, the correction climatic coefficient for different regions of Ukraine is investigated which is used to determine the share of heat consumed by the consumer when installing heat cost allocators. A numerical analysis of the calculated values of the heat losses of the premises for a residential building according to the regulatory climate data of Ukraine by months of the heating season was carried out. By calculation, for such cities as Kiev, Kharkov, Zaporozhye and Lviv, correction climatic coefficients. The discrepancies between the values of the correction factors and those currently in force in Ukraine are revealed, which confirms the relevance of the conducted studies. According to the data obtained and their comparison with the existing correction factors we can draw a conclusion that for fair calculation of heat cost allocation to heat energy to correct them in accordance with the building regional location taking into consideration climatic zones of Ukraine. The proposed correction factors will ensure the accuracy of accounting for individual consumption and the actual energy consumption at the consumer, which is necessary for the implementation of Article 9 of the European Parliament Directive 2012/27/ EU.

The role of polydispersity of zeolitic tuff in the realization of its properties as an active mineral addition and optimization of granulometric composition of concrete at the level of the mesostructure have been confirmed. The function of a polydisperse zeolitic tuff and perlite in the creation of water reserve for hydration of cement in conditions of reduced relative humidity and in case of improper curing is substantiated. In dry hardening conditions, concrete containing polydisperse mineral components such as perlite and zeolitic tuff are characterized by a slightly lower percentage of compressive strength reduction in comparison with concrete without additions. Flexural strength of moist cured concrete with polydisperse zeolitic component is 8 and 12% higher than concrete without additives at 28 and 90 days respectively.

Selected structural changes which have to be introduced in the existing on the ground tanks used to store liquid petroleum products, should these tanks be further kept in service under the same or modified service regimen, are discussed in this paper. Modernization of these tanks within the scope described by the authors is required due to the increasing environmental requirements. In particular, the improved sealing of the previously used single shell tank bottom structure has been considered. This may be achieved by adding an additional steel or composite second bottom with monitoring space, or alternatively by raising the whole tank and installing underneath it a geomembrane impermeable to petroleum materials and equipped with leak monitoring system. An application of lamination techniques with modern composite materials has to be accompanied with development and installation of a fail-safe system to ground the electrostatic charges generated by friction on the shells modernized in such a manner. The second modernization technology discussed in this paper is related to adaptation of the typical on the ground cylindrical storage tank equipped with floating roof to store the jet fuel. In this case the recommended solution is an addition of a lightweight aluminum dome.

The management of sewage sludge at wastewater treatment plants is a very important technical, economic and environmental issue. One of the popular environment-friendly methods of processing sludge is methane fermentation – a complex biochemical process through which organic matter present undergoes biochemical decomposition in anaerobic conditions, with the final products being biogas (a valuable source of energy), as well as a digestate that constitutes an excellent organic fertiliser. Most often, biogas generated provides energy that supplies a wastewater treatment plant’s own needs (given that such plants exert a high demand for both electricity and heat). Addressed here as an example is biogas production at the WWTP in the city of Zamość, whose management of sewage sludge is analysed in detail, with account taken of the balance between quantities of sludge and biogas generated. Methane fermentation there is found to represent an effective technology by which energy may be recovered from sewage sludge, with the biogas obtained proving a very valuable fuel that the plant can put to use readily.

Designing new and reconstructing existing water supply networks are based on water demand. Most of the existing water supply networks in Ukraine are designed for a higher amount of water flow in the pipes, which causes a decrease in the velocity of water, an increase in the duration of stay of water in the network and deterioration of water quality. Ukrainian water demand (average daily per year) of drinking water is higher than Slovakian: up to 35% for residential houses with water supply and sewage without baths; from 11% to 74% for houses with local water heaters; from 59% to 96.5% for houses with centralized hot water supply. For the majority of other consumers, the divergence of normative water consumption is insignificant. A comparison of water consumption in Ukraine and the Slovak Republic has been performed for the selected example in residential houses, industrial plants, irrigation of greenery and street sprinkling of surfaces. For the selected example, the total average water demand in Ukraine is higher than in the Slovak Republic by 44.41%, maximum water demand by 39.88%, minimum water demand by 9.98%.

Today, more and more attention is dealt with environmental issues and sustainable construction in society. The construction industry is demanded on the amount of energy consumed and greenhouse gas emissions. Using sustainable construction is a fundamental concern for society to lead to environmentally sustainable future. Sustainability contains social, economic and environmental aspects. In last years, we have seen an increase in innovation in the construction industry sector. Support in buildings construction´s innovation is one of the major ways to realization, manage and operate the building’s life cycle. Making these processes more efficient leads to the promotion of sustainable construction. This article is pointing out the different aspects of sustainability and provides an overview of innovative technologies used in the construction sector and focuses on their contribution to promoting sustainable construction. Special attention is dealt with technology of building information modelling, especially its benefits and tools to support building sustainability.

In drinking water supply systems, formation of biofilm is associated with technical and hygiene problems which may cause an increased health risk. Techniques of monitoring therefore need to be optimized and adapted to yield valid and informative data. The aim of this research was to develop an effective method of biofilm sampling from the surface of the pipe material in order to perform quantitative analysis and identify the advantages and limitations of the quantitative determination of the number of microorganisms using three different microbiological methods: classical heterotrophic plate counts (HPC), flow cytometry, luminometry. Based on the conducted research, the following was concluded: the best method to detach the biofilm from the surface of the coupons is mechanical separation with a sterile swab. The swab was placed in 30 ml of Ringer’s solution and exposed to ultrasounds, the optimal duration of ultrasounds, is 60 s for sonicator power of 28 W. Attention should be given to the volume of solutions, which is selected depending on the operating time and the sonicator power (30 ml is optimal). Due to the simplicity and speed of obtaining results, the luminometric ATP measurement has been established as the best method for the quantification of microorganisms in biofilms.

Prestressing of reinforced concrete structures with CFRP strips is highly effective and currently developing method of strengthening. Mechanical anchorages are usually used in this technology in order to introduce and permanently maintain prestressing force in the CFRP strips. The paper presents the results of static tests of CFRP strips anchorages used in strengthening system recently developed in Poland. The system consists of two main elements: mechanical steel anchorages mounted on both ends of a single CFRP strip and a relevant tensioning device. The tests included two types of anchorages: N-type with hybrid bonded/riveted joints between steel plates and CFRP strips and S-type with bonded/bolted joints. Both types of anchorages have been tested in axial static tests in five series. The anchorages in subsequent series were modified based on the test results and the conclusions of previous series. The main goal of the tests was to establish the carrying capacity and the efficiency of the anchorages. The experimental results allowed for significant increase of anchorages carrying capacity in comparison with initial design and showed that the S-type anchorages exhibited a higher values of carrying capacity as well as higher level of homogeneity.

Scaffolding is a special structural system used in buildings. Despite their simple construction, they require proper design. In the analysis of scaffolds, not only the strength of the elements themselves plays an important role, but also the knowledge of the characteristics of system nodes. Currently used programs for designing and calculating structures are able to take into account the influence of joint characteristics. That is why some manufacturers give flexibility properties on the details of their solutions. The article presents the results of experimental tests of modular scaffold nodes. A series of four types of tests was carried out; tensile tests of the joint when the force is applied to the ledgers, tensile tests of the joint when the force is applied to the diagonal of the brace members, tests the joint for bending in the plane of the system standards and ledgers, and bending tests in a plane perpendicular to the plane of the system. The test results were compared with the values given by the General Building Authority Approval.

The paper presents background to method for calculating the minimum reinforcement controlling the crack width and points out some important factors, which should be considered when applying the simplified method for controlling crack width in beams subjected for bending resulting from direct loading. Special attention was put to proper use and limits of Table 7.2N in Eurocode 2.

Theoretical and experimental investigations of the influence of the molecular structure of polyurethane on its vibro- and electroinsulation properties have been carried out. It was established that the rheological model of polyurethane and rubber corresponds to the Kelvin resilient-&-elastic solid. However, due to the lateral electrostatic repulsion between the C = O groups polyurethane has a higher resilient component under compression and subsequent reverse deformation and a higher elastic constituent during the reset after the tension. It conditions the enhanced ability of polyurethane to absorb vibrations in comparison with rubber. Due to the energonegativity, the C = O groups provide a high electrical resistance for the polyurethanes. The experimental data show that polyurethane compositions provide a decrease in the vibration velocity of the rail seat plate in comparison with the track on rubber rail pads and an increase in the electrical resistance between the rail and the plate. The availability of the C = O groups in polyurethane compositions is confirmed by the analysis of the IR-spectra of absorption. When polyurethane is operated under insulation conditions the intensity of C = O lines is decreased with time and it is indicative of the rupture of double bonds, loss of those groups and the degradation of rheological and electric properties.

The article presents the results of research aerated concrete properties, in which a part of the mineral filler is replaced by a light, environmentally friendly organic filler – flax straw. The flax straw is a renewable and 100% natural waste of the agricultural industry, which can be widely used to obtain thermal insulation materials. It has been shown that the partial replacement of the mineral filler in aerated concrete by the flax straw can lower its average density by 44 and 51%, respectively. The influence of water-solids ratio on strength and average density of flax aerated concrete is investigated. It is established that the optimum value of water-solids ratio is 0.8–1, at which the average density of aerated concrete is 300–400 kg/m3 and the compressive strength is 0.62–1.1 MPa. It is shown that in order to decrease the average density of aerated concrete on the basis of vegetative fillers, the temperature of the aerated concrete mixture should be 35–45 °C. Thus, the developed thermal insulation material – aerated concrete on the basis of organic and mineral fillers can be used for the construction of low-energy buildings, which is consistent with the principles of sustainable development in construction.

Currently in Poland, similarly as in the other EU countries, road bitumens are tested and classified with regard to mainly the penetration value determined at the temperature of 25 °C. It should be noted that this classification is not correlated with the climatic conditions in which the bitumens are to serve in the road pavement. Towards the end of the last century a new system of bitumen grading was developed and implemented as part of the American Strategic Highway Research Program (SHRP). This paper presents the results of analyses concerning the determination of the temperatures at which bituminous binders serve in the Polish climatic conditions. A division of the area of Poland into climatic zones depending on the required performance grades (PGs) determined for bitumens on the basis of climatic data from meteorological stations for a period of minimum 20 years is presented. It is proposed to select bitumens depending on the climatic zone in Poland, taking into account the proper probability level which follows from the road class.

The work has the cognitive goal, expressed by the desire to expand knowledge and re-evaluate some of current views on the safety of collective water supply systems (CWSS). These systems belong to the critical infrastructure of urban agglomerations functioning. The work presents the systemic approach to the problems of threats. The interpretation of the Pareto principle in the safety assessment was presented. The system resilience indicator was defined on the basis of direct and indirect risk. Global unreliability indicators referring to the supply of water was presented. The mentioned issue of preliminary analysis of the water supply services level is aimed at developing standards in this area.

A method has been developed that, with the availability of appropriate technical types of supplies, is an effective technology for conducting full-scale studies of structures exposed to temperature fields without the need to create temperature effects. Experimental effective test method, with the availability of appropriate technical types of supplies, for conducting full-scale studies of structures under the impact of temperature actions without the need to create temperature effects was developed. Its distinctive features are the simplicity of experimental part, the low cost of test itself, the physical clarity and logical foundation of results being obtained. The theoretical foundations of the method are based on the Betty-Maxwell energy reciprocity principle and consists in the replacement of a heated or cooled object with an unheated one. New experimental results shows that thermal displacement of the element (structure) in a predetermined direction and at a given time depends on the modulus of deformation of the 1st kind E, coefficient of transverse deformations ν, the thermal expansion coefficient α and the 1st invariant of deformation tensor defined in a predetermined number of points of the heated (cooled) element loaded by a single force. A program of experimental testing was suggested.

The article describes the studying of objective tendencies of hydropower engineering development for improving the level of providing the increasing energy needs of society. The research method is based on detail analysis of existed information on water resources using for electricity production and discovery of promising avenue of hydropower engineering development. It is highlighted the role of hydraulic energy as one of main types of renewable energy. The article elaborates on the four main tendencies for hydropower development, i.e. intense increasing of hydropower capacity, expansion of the HPP and PSPP functions, construction of the high head HPP and PSPP, enhancing role of small-scale hydropower plants. These tendencies are relevant for global and Ukrainian hydropower engineering. The authors’ view on perspective trends of hydropower development are shown. Among these trends the four main tendencies are emphasized. The received results are useful during considering the specific tasks for establishing hydropower facilities and attracting appropriate investors for their implementation.

It was shown that one of the ways for obtaining effective high strength concrete is using ultra-rapid hardening Portland cement compositions. The possibility of development of such compositions on the basis of ordinary Portland cement for high strength concrete with using nanotechnological methods of the modification of cementitious matrix by introduction of nanoscale particles of C-S-H phase and polycarboxylate type superplasticizer is shown. The complex nanomodifier results in high water reduced effect with decreased interparticles distance, accelerated formation of hydrosilicate gel with a more homogeneous distribution of hydrates in a limited intergranular space. Nano-modified Portland cement compositions reaches 54% of standard strength after 24 h. It allows to categorize them as ultra-rapid hardening. According to the indicator of standard strength (Rc28 = 84.8 MPa), they refer to high strength binder. Effectiveness of nano-modified ultra-rapid hardening Portland cement compositions for high strength concrete under different curing conditions is confirmed.

In this paper the results of calculation of eccentrically compressed reinforced real scale concrete columns strengthened with carbon fiber reinforced polymers (CFRP) laminates is presented. In order to check the calculation results, four real scale experimental reinforced concrete columns 2200 mm long and with sectional dimensions 180 × 140 mm were manufactured. Reinforced samples were strengthened with a 25 mm CFRP laminates. The calculation was made according to Eurocode 2. The usage of carbon laminates limit strain introduced into the calculation, is proposed. On the basis of normative documents the block diagram of calculation algorithm for such structures is created. As a result of the calculation it was established that according to the presented calculation algorithm the divergence between calculated and experimental values reaches 5 … 10%, while the experimental data exceeds the theoretical ones. It makes it possible to reliably calculate and design strengthening of eccentrically compressed RC structures with CFRP laminates according to the algorithm presented in the work.

Paper represents an architectural and construction system for the erection of civil and residential buildings of monolithic reinforced concrete with a given internal and simple external geometry named “MONOFANT”. All structural elements of the frame building of the “MONOFANT” system (foundation, columns, rigid elements, floors and coverings) are made of monolithic reinforced concrete with hollow sections due to the installation inside of them inserts - void formers from organic and inorganic insulating materials. Main advantage of this system is creation of structures with the given stress-strain state. It is possible to design structures with maximum resistance on the fixed material consumption or systems with the lowest material consumption on the fixed resistance. One of the most interesting and yet unsolved questions while designing elements of this system is the cutting of the organic inserts which provides minimum waste of material. In this connection we considered traditional “MONOFANT” slab of civil building and fulfilled the analysis of the features of stress-strain state together with solving the optimal cutting task. Procedure and main results are presented in this paper.

In the present scientific work there is done the comparative analysis of two Slurry Surfacing mixes – systems on orthophosphoric and hydrochloric acids. It was determined that application of orthophosphoric acid for preparation of bitumen emulsion on oxidized bitumen leads to the substantial improvement of cohesion strength build-up rate – in comparison with identical system on hydrochloric acid. So as to receive the similar indices of cohesion strength build-up – the orthophosphoric-acid-based system allows using less amount of bitumen emulsion than required amount for the system on hydrochloric acid.The results received witness about the different natures of breakage and cohesion strength build-up rate for systems on hydrochloric and phosphoric acids. As a confirmation of this fact there can be considered the possibility of using (in the systems with orthophosphoric acid) the aggregates which by methylene blue criterion are unsuitable for such technologies.The orthophosphoric-acid-based Slurry Surfacing mix systems’ properties obtained allow forecasting the substantial advantages of using these mixes at limit-permissible (for bitumen-emulsion technologies) ambient temperatures.

The fatigue life of steel elements is usually predicted by classical nominal stress method. Such approach is very convenient, when design model of structure is based on bar elements. But the level of analysis in steel structures is still increasing. There are used more and more sophisticated FE packages, which offer shell and 3D elements instead of classical bars modeling. They allow to include real shape of elements and existence of welds, bolts and other joining components. Results obtained from such analysis contain many stress raising effects and can be easily utilized in modern approaches of fatigue life based on local stress values, e.g. structural (hot spot) stress method. Development of modern computational FE packages make prediction of fatigue life using local approaches possible and easier. Major obstacle in wider application of numerical methods for the fatigue assessment of steel structures is apprehension of designers about accuracy of local approaches. The focus of presented research has been on comparison of fatigue life predictions based on nominal stress method and on structural stress method, made for a couple of constructional details. Paper presents influence of geometrical parameters on stress concentration factors and also highlights a wider flexibility of structural stress method.

The fire situation aspects especially in case of carbon fiber reinforce polymer (CFRP) strengthening of RC elements are one of major design factor in civil engineering today. Here the next options for CRFP strengthening is discussed. Option A1 when CFRP is not necessary under fire scenario and Option B - FRP is necessary under a fire scenario. Two parameters are related to the fire scenario. First parameter is reaction to fire and second parameter is structural members’ fire resistance. The need for fire protection and fire resistance of RC structural elements is obtained by means of a calculating following a Eurocode procedures. Simplified expected temperatures profiles calculation process is presented. Structural analysis under fire situation of strengthened unprotected and protected member is shown as well. It is concluded that under fire scenario according to Eurocode calculation methodologies the requested fire resistance (R30–R240) can be fulfilled with no additional measure or protection at more than 80–90% of the real cases.

Comparing construction to other industries shows that while they have increased productivity, the construction industry lagged behind. One of the way to increased productivity in construction projects is application of industrialized construction which presents a modern method of construction. On the other hand, current consumers require individually manufactured products according an approach “made for me”. The connection of individual customer requirements and industrialized construction is considered a challenge for modern construction industry. The solution lies in applying the principles Construction 4.0 which require the transformation of the construction industry towards the 4th industrial revolution, from automated production to a greater level of digitalization. The aim of paper is to analyse the options of customization (customer requirements) in the various stages of construction project - project conception and construction design, construction elements manufacturing and construction.

Development of digital technologies and processes including Internet of Things (IoT) applications is central to the required transformation of the construction industry within the frame of Construction 4.0 concepts originated from the fourth industrial revolution Industry 4.0. The construction sector has vast potential to improve productivity and efficiency thanks to digitalization, innovative technologies and new construction techniques. The new tool Concremote, offered by multinational expert in solutions of formwork, uses digital sensors to measure the in-situ concrete maturity gradient and with this data it calculates early age strength. Being able to measure in real time the development of in-situ concrete maturity can reduce striking time and thus reduce cost of formwork. The aim of the case study is to demonstrate saving of formwork cost due reducing striking time through intended employment of the tool Concremote in construction of slabs. The cost of slab formwork was estimated in different variants of formwork striking times. For most variants of construction time and striking time, it was verified that the saving of the formwork cost due reducing striking time is higher than cost of the Concremote employment in the referenced construction.

The costs of removing water pipe breakdowns can be divided into the costs of materials, equipment and labor. The study concerns the analysis of the costs of the equipment used to remove water pipelines failures. The basis of the work are operational data collected during the removal of 302 pipe breakdowns in the city with a population exceeding 100,000. The dependence of these costs on the diameter and material of the pipe was noticed, they increase with increasing diameter. The differentiation of costs is also the result of the location of the pipeline - where a high degree of soil compaction is required, its replacement is carried out, which results in an increase in the costs of both materials and equipment used. In the water supply system under study, the average cost of equipment used to repair the failure was an average of PLN 2178 (price level 2017), was higher than other costs, which amounted to a total of PLN 1317.

In construction, the usage of silicate additives is constantly expanding. Depending on the type and amount of mineral additives and the time of cement hydration, the structure of basic cement hydration products varies and it affects the properties of cement pastes. To ensure general-purpose cements of high quality, it is necessary to monitor constantly of activities of used mineral additives. To investigation of activities of additives used physical and chemical methods. However, during continuous production, such methods are time consuming, so, it is necessary to use some quicker way to check activities of mineral additives in cement. Therefore, in the paper, impact bending strength method is proposed for evaluation of mineral additives’ activity. However impact strength of cement pastes depended on curing conditions. Unbound water in capillary and gel pores works as shock-absorbent during impact bending tests. Therefore, impact bending tests, should be performed on samples stored in air-dry conditions.

The paper describes experiences from the stabilization of landslide slope. Evaluation of the landslide stability is one of the most important problems in geotechnical engineering because failure could cause catastrophic environmental. Analysis of the landslide slope was performed using FE method. It was possible to evaluate two alternative stabilizing techniques and to choose the optimal one. Methods of stabilization consisted in the use of gabions wall and stabilizing piles, as the supports of the slope. Although the gabions wall were able to stabilize the slope, increasing the number of gabions and their weight was not effective in increasing the safety factor. The proposed pile technique was more effective. The numerical analysis provided a good prospect to optimize the design of stabilizing landslide slope. Using piles in the base of the slope with their anchoring in soil can improve the stability of the analyzed area with an increase in the stability factor to a safe value FS = 1.6. The resulting improvement in stability of slope will be sufficient in accordance with the technical requirements. The numerical simulations of the landslide showed that such analysis could be a useful tool in the design process landslide stabilization.

The use of activated mineral powder (mineral filler) obtained with the aid of the RENA-Aquador activator for mineral materials reduces the consumption of bitumen by 15% while simultaneously improving the physical and mechanical properties of asphalt concrete pavings. This indicates the high efficiency of activating the mineral filler by means of this activator.

The results of the study of the impact of the reinforcement of cement concrete with polypropylene fiber of various types on the strength and crack-resistance characteristics are presented in the article. Consumption of the polypropylene fiber of two types (ordinary and deformed) was taken as the factors. The methods and criteria of fracture mechanics, which are based on the fracture toughness and fracture energy, allowed to carry out a quantitative and qualitative assessment of the effectiveness of addition of two types of polypropylene fiber. The optimum ratio of contents of two types of polypropylene fibers is determined, at which the maximum values of strength and crack resistance of concrete are reached.

Many companies are implementing Lean management in order to be more competitive. The goal of management in the construction industry is the reasonable allocation of resources in order to complete the project in accordance with the approved budget, time allowance and the set quality level. Lean management tools can significantly contribute to increasing the efficiency of resource use at a construction site through their rational use. In the article, based on surveys, expanded with an expert interview, the results of using lean tools in the construction industry are presented, as well as their impact on improving the construction process from the management’s point of view when executing a construction project. According to the results of the survey, it is clear that lean management is still unknown and not widely used in the construction industry outside large construction companies. Based on observations of the implementation of construction processes, the areas of implementation possibilities were identified and barriers to Lean implementation in the construction sector were identified.

The article describes the optimal design method for three-hinged arches with given topology. The examples of optimization of the three-hinged arch with constant and uniform-strength cross section subjected to the distributed load are considered. The optimization technique is based on the geometrical parameters and design features of the systems. The calculations of volume material of three-hinged arches for the uniaxial compression stress strength conditions are shown. The results of comparison of the arch volume of material s depending on the axis shape are presented.

Efficient and rational use of energy carriers is one of the important issues of energy policy of the EU and Ukraine. In this regard, it is important to design systems that will be based on the use of renewable or inexhaustible energy for efficient and rational use of the fuel and energy complex of Ukraine at the international level and heat supply of houses at local levels. This solution can be achieved by using solar systems to generate electricity and heat. In general, territory of Ukraine belongs to the average zone with solar radiation intensity. The value of annual solar radiation per 1 m2 on the earth’s surface has a static distribution. The work considers energy efficient solar system combined with external fence of energy-efficient building. The paper describes the data of functioning mechanism of the solar collector using mathematical modeling. The article analyzes the heat technical characteristics of the proposed solar collector for the possibility of their subsequent installation and application by consumers.

The aim of the investigation is determination of compressing coefficient and air jet’s initial velocity under the condition, when bus passenger compartment is filled to a great extent with seats and passengers (sitting and standing).Air distribution experimental research was carried out in passenger compartment of different LAZ (Lviv Bus Plant) bus production models both at presence and absence of the passengers (in filled and empty bus passenger compartment). Air was supplied at the various flow rate through the different air distribution devices. Air exhaust was realized through the driver window. Air jet’s initial velocity of outlet from inflow hole and axial velocities in the bus passenger compartment service area has been experimentally determined. Measurement of the air jet’s velocity was made by thermal electrical anemometer Testo-405. Universal calculating equations of air jet’s velocities and determining factors have been expressed as dimensionless. Velocity of air jet’s outlet from inflow holes of different size and axial velocities in empty and filled bus passenger compartment of different production models have been measured. Dependence of compressing coefficient from three factors is determined and presented as a chart. Obtained chart has been approximated by equation.

The article is devoted to decision of actual task of air distribution efficiency increasing due to swirl and spread air jets to provide normative air parameters in the production apartments. The mathematical model of air supply with swirl and spread jets in that type of apartments is improved. It is shown that for reaching of air distribution maximal efficiency it is necessary to supply air by jets, that intensively extinct before entering into a working area. Results of air flow simulation are presented. The graphical and analytical dependences are shown. Dynamic parameters of air flow that is created due to swirl and spread jets has been determined. Results of experimental investigations of air supply into the room by swirl jets are presented. The results of the theoretical and experimental investigations of dependence of the attenuation coefficients and coefficient of device local resistance from the angle of inclination of the twisting plates are presented. It was established that an increase in the angle results in increase of the attenuation coefficients and in decrease of the resistance coefficient of two-flow air distributor (TFAD). The optimum angle of the plates is determined considering aerodynamic and energy aspects.

The aim of this work is the investigation of different outlets acoustic properties from the different air jets leakage, which flow out from outlets under varying conditions. Such holes as: rectangular chink for a compact air jet; rectangular chink with a bend for a flat air jet; round outlet for a swirl air jet; round outlet for air jets interaction; rectangular chink for the flat air jets interaction. In this article has been determined relationship between such factors as a noise level, air flow rate and inflow hole size at air jet leakage. There are considered some sources of noise: fan, vibration of ventilation piping metal walls and aerodynamic noise of the air jet flowing out from outlet. There has been designed the chart of sound level’s dependence from the initial air velocity and dimensionless outlet square. Obtained curves was approximated by equation. Comparing chart for the round, compact, swirl, flat air jets and their interaction, which flow out from a rectangular aperture with a bend, rectangular chink’s aperture and cylindrical pipe with a bend, we shall note that noise level is the highest at flowing out of flat jet in cause of a rectangular chink with a bend.

In pursuit of energy savings, reducing production costs and securing heat to buildings, we are trying to find new suitable solutions. The intention is also supported by the requirements for energy efficiency of buildings. The requirements are defined by the value of the global indicator – Primary energy. In the article we focus on the category of residential buildings. From January 1st 2016, buildings will be refurbished to meet category A1. In cases justified by high investment intensity without return, it is possible to accept the reconstructed building with classification in category B. Measures are usually implemented on building structures that generally have the greatest impact on reducing heat demand. However, heat is “produced” in various sources to which energy is supplied to produce it. The total energy delivered for global assessment is driven by the efficiency of production, and the quantity of “primary energy factor,” which is different for different types of energy. It is the primary energy factor that fundamentally influences the category to which the building under assessment gets. In the article, we will make a comparison on a real certified object, with the impact of different primary energy sources on the overall classification of the object.

The paper presents optimisations of industrial sliding gate structure of 6 m wide. The optimisation process was carried out in two steps. In the first step, the structure of the gate was optimized due to its weight and the value of vertical displacement of the corner node of the gate. In the second step, the cross-section of the ground track of the gate was optimized. It was assumed that the gate is loaded with its self-weight and wind pressure. The calculations were made using computer-aided design. The following programs were used: SHAPE-THIN, Autodesk Robot Structural Analysis and ConSteel. The structures of the gate was made of SHS profiles. The ground track of the gate was made of cold formed profile, of sheet thickness 4 mm. All elements were made of S235 steel grade.

Principles and methods for design of surface reinforcement required to control cracking on side faces of reinforced concrete beams are presented and discussed. On the basis of the modified concept for assessing the effective tension area in the beam’s cross-section, which dimensions was assessed using the fracture mechanics of concrete, a method was proposed to calculate cracks width over the entire depth of beam provided with surface reinforcement. Proposed method allows to determine the quantity and distribution of surface reinforcement above the main reinforcement axis necessary for the acceptable width of cracks.

In the current period of scientific and technological progress, new concepts, tools and methods of solution must fulfill the principles of a democratic society that dictate us to ensure the quality of the human environment for future generations. Part of this challenging task is the timely assessment of the potential impacts of the proposed activity on the environment and public health with acceptable environmental risk. For this reason, it is necessary to develop the theory and to apply the methods for the systematic investigation of the consequences of projects, constructions, plants, facilities and other interventions on the environment and the population. The aim of the paper is to analyze the current state of the impact assessment process and to point out the existing methods used in the impact assessment process. The work points out the possibility of improving existing methods of impact assessment of proposed activities by applying risk analysis in the process of applying the impact of water structures on the environment. The use of risk analysis methods to assess the impact of activities on the environment and population health is undoubtedly an original and innovative proposal. The paper has a clearly defined original methodology and solution concept.