Table of contents

The 12^th International Scientific Conference of Civil and Environmental Engineering for the PhD. students and young scientists below 35 years under auspices of the dean of the Civil Engineering Faculty of the Technical University of Košice assoc. prof. Peter Mésároš was planned to be held on 22^nd – 24^th April 2020 but due to known circumstances was postponed. The postponed conference is planned to be held on 15^th - 16^th of October 2020 in Štrbské Pleso, the High Tatras, Slovakia. This traditional meeting of PhD. students, their supervisors and young scientists working in the field of civil engineering and environmental science is organised by the Faculty of Civil Engineering of the Technical University of Košice, Slovakia. The Young Scientist 2020 offers an international platform for the dissemination of original research results; provides a pleasant environment to present new, great ideas of young researchers and discovered advances in the field of civil engineering and related interdisciplinary topics. It is an opportunity for PhD. students and young researchers to discussed scientific topics and research results of topical issues in civil engineering, to share their knowledge and experiences, to collaborate in innovative designs and proposals. In addition, the valuable presentations are usually extended by a social program including the interesting field trip in the High Tatras.

The Conference usually assembles more than 60 delegates, from the Slovak Republic (Technical University of Košice, Slovak University of Technology in Bratislava), the Czech Republic (Czech Technical University in Prague; Brno University of Technology, Mendel University in Brno, VSB-Technical University of Ostrava), from the Croatia (Josip Juraj Strossmayer University of Osijek) and from the Poland (Cracow University of Technology of Cracow) including PhD. students and other representatives from the universities. The scientific contributions involved a wide range of research fields: Building Physics and Services, Sustainable Architecture and Energy Efficiency, Statics, Dynamics and Modeling, Structural Engineering and Bridges, Transport and Geotechnical Engineering, Construction Technology, Organization and Management, Construction Economics, Marketing and Management, Building Information Modeling, Innovations in Construction Design and Technology, Environmental Engineering, Healthy Indoor Environment, Material Engineering and Recycling as well as Sustainable Water Management.

Forty contributions have been selected to be published in the volume of Journal IOP Conference Series: Materials Science and Engineering. The organizing committee appreciates the enormous work of the both the editorial board and reviewers in the preparation of this volume. Many thanks also to all authors for their flexibility and meeting deadlines.

assoc. prof. Martina Zeleňáková

assoc. prof. Peter Mésároš

assis. prof. Vlasta Ondrejka Harbul'áková

Delegates

Young Scientist 2020, October 15 - 16, 2020, High Tatras, Štrbské Pleso, Slovakia

List of author names are available in this pdf.

List of Editors, Technical Editors, Scientific Committee, Organising Committee, Review Statement and Reviewers available in this pdf.

All papers published in this volume of IOP Conference Series: Materials Science and Engineering have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

The aim of this paper is to outline the main functionality of Parasitic Architectural Forms (PAF), extend on potential utilization of it in the digital era, discuss the possibility of architecture being self-designed. I raised a question if architecture could be self-growing, self-developed and self-healing. This issue is being solved by this concept of PAF. Absence of artificial intelligence in the process of design in the architecture field offers a space for new research. Also, it generates options for yet uncharted views for experimental creation and urges us to ask of what are we, people, and computers currently capable.

The aim of the paper is to create a concept of a glass system independently reacting to the parameters of the environment in which is located. Autonomous insulation unit is responded to changes of environmental parameters, capable of evaluating mode efficiency with and without the use of selective layers. Parameter specification of individual modes, description of operation is needed. As a result, a construction scheme of the glass system is proposed.

Nowadays asphalt mixture is the most used material in the construction and reconstruction of roads. It is used for its advantages, such as availability of materials, flexibility and no need for dilatation. However, the asphalt mixture has one disadvantage, namely temperature sensitivity. At different temperatures it exhibits different physical-mechanical properties. For a better understanding of the physical-mechanical properties of the asphalt mixture, we can use complex rheological models. Complex rheological models can describe the viscoelastic behaviour of the asphalt mixture with a high prediction. Laboratory tests are required to determine input values for complex rheological models. The article is focused on the analysis of asphalt mixture in the indirect tensile strength test and compare with numerical solution.

The paper presents the results of construction waste treatment for possible replacement of natural aggregates in cement composites. The individual processes of construction waste treatment for the purpose of obtaining the required fractions 0/4 mm, 4/8 mm and 8/16 mm are described. It deals with the so-called recycled aggregate, which will subsequently be used in cement composites as a substitute for natural aggregate. The properties of individual fractions of recycled aggregate are presented, both in terms of composition, density, water absorption and granulometric, mineralogical and elemental composition.

The application of mathematical models has been expanding in the field of sanitary and environmental engineering. Mathematical models are used in the design and assessment of sewer networks and their facilities. Sewer network models make it possible to create a model of hydraulic and Physico-chemical processes in wastewater flowing through the sewage network. The number of extreme rainfall events is increasing due to climate change. It causes a collapse in the infrastructure of urbanized areas. It is possible to investigate the flow of wastewater under extreme rainfall and to propose measures to eliminate adverse events using mathematical models. Nowadays, it is possible to use modern calculation procedures, which are used to dimension and assess existing facilities. This paper aims to focus on the application of numerical models in the design and assessment of combined sewer overflow chambers. The combined sewer overflow serves to carry away a part of the rain flows from the network to the nearest suitable receiving water body. Their main task is to reduce the uneven load of wastewater treatment plants by rainwater. The combined sewer overflow chambers distribute the inflow into the flow going to the wastewater treatment plant and the lightened flow going to the receiving water. The aim of this paper is to summarize the knowledge of CFD modelling and to get acquainted with the basic principles. In brief, the normal flow describes its simulation using two basic models. Finally, it focuses on the recapitulation of foreign studies and their use in the assessment and design of relief chambers and regulatory objects of the single sewer networks.

The aim of the paper is to evaluate the technological and economic demands on the construction of multi-storey reinforced concrete monolithic buildings for administrative purposes incorporating the stages of construction, technological stages and selected partial construction processes.

The entry criteria for objects that are included in monitoring and evaluation are their identical location, used technologies, mechanization, built-in materials and their purpose.

The purpose of the paper is to prepare tables for the professional and academic public for a rough idea of the proportional representation of time and financial consumption in the construction of this type of object, for selected stages of construction, technological stages and selected partial construction processes.

The article deals with the topic of a crystallizing waterproof admixture using in concrete. This type of admixture is designated for making a hardened concrete more durable by minimizing its permeability. Considering that concretes of higher strength classes meet the requirements for durability parameters in most cases, in this experiment 3 low-durability (in terms of high w/c ratio) concrete (D_max8) batches were mixed. From each of mixture, 2 sets of samples (with and without the admixture) were prepared for depth of penetration of water under pressure test, strength test and water absorption test after 28 days of curing. Likewise, samples for microscopic visual assessment of crack-filling process were produced. Cracks onto these samples were intentionally introduced after their curing in time of 7 days and subsequently were further cured under water and regularly observed. According to the results, tested admixture acted more counter-productive than helpfully.

The presented paper deals with the evaluation of the quality of the indoor environment in a new school building with modular construction. The required short-term measurements were carried out in two selected classrooms. Selected physical-chemical factors such as thermal comfort, sound level, lighting conditions, concentration of CO₂, particulate matter (PM₀.5-PM10) and total volatile organic compounds (TVOC) were monitored. Based on the obtained results, it was shown that the values of operative temperature, relative humidity and air velocity measured in selected rooms meet the requirements given by legislation. The average CO₂ concentration was exceeded in both classes, which may lead to headaches and concentration problems in pupils. Concentrations of PM_2.5 were below the acceptable limit, while PM10 concentrations were exceeded in both classes. The recommended TVOC concentration of 200 ug/m³, which does not yet cause discomfort and has no adverse health effects, was exceeded in both classrooms.

This article is dedicated to make people familiar with process of creating new construction of modular green roof panel. Article also shows creative process of prefabricated panel and all versions of its construction from the first attempts to final ecological modular panel for green roof. Article also describes problems of every version of modular panel which was created, and solutions which were made for final versions of green roof modular panel. Article also shows a final modular panel with its construction and possibility of its use on the roofs. In the article you can also read about tests which will be done in the future for verification of right construction of green roof panels and its behaviour in the real outside conditions.

In our research, we are focused on analysing the impact of illegal rainwater connections on the sewage network. During the normal operation of the sewage network, rainwater cannot be present. These heavy rains flows are extreme during rain events and the sewerage system is significantly overloaded and functionality it is reduced. Our study is based on the real data of the sewerage network and selected area of interest. In the assessment of illegal connections of rainwater, we use rainfall data according to the relevant ombrographic station.

In-situ research and laboratory examination provided on concrete core samples from old bridge structures confirmed that a thin layer of ordinary cement-based render coat protects the underlying concrete from carbonation. The average measured value by phenolphthalein test was less than 2 mm after more than 100 years of service life in exposure class XC3 of EN 206. Low carbonation depth is explained by the presence of a thin (2-4 mm) layer of the protective render coat (PRC) situated on the bridge concrete. The place, where the PRC was of good quality was almost impermeable and the carbonation of the concrete underneath was even 0 mm. If the PRC locally spalled, the carbonation depth of the same concrete, at the same structure and environment reached at this place even more than 80 mm. It was observed that low carbonation of concrete significantly depends on the non-permeability of the PRC. A narrow free space filled with the carbonates causes increased non-permeability of the PRC creating thus the built-in limestone-based (anti-carbonation) barrier with the ability to dramatically reduce CO₂ penetration into the beneath concrete over time. Values from in-situ and laboratory research are presented in the article with the explanation of these phenomena.

At present, restoration of historic buildings is a difficult process. The most common problem of historic buildings is increased moisture, because waterproofing is missing and thanks that water can be transported in porous material by capillary forces. There is several simulation software available, which can include many factors such as water transport from the ground, sun radiation, impact of driven rain. Also it includes thermal conductivity, specific heat capacity and water vapor diffusion factor, which are depended on content of water. For correct assessment of hygrothermal behaviour of these buildings and find suitable retrofit strategies, hygric and thermal properties are needed. When we want to use simulation software for assessment of hygrothermal behaviour of historic structures, we need to know heat and water transmission parameters of sandstones. In this paper are presented two water transmission parameters and that water absorption coefficient and capillary water content. For the test measurement of these parameters was used clay brick. The water absorption and capillary water content are obtained by experiment of one-dimensional transport water. The results are compared with values of clay brick, which are presented in German material database.

Cross laminated timber (CLT), as a versatile engineered timber product, has in recent years become well-known and of global interests. The orthogonal laminar structure allows for application as beams, walls or panels for both out-of-plane and in-plane loading conditions. The work presented here concerns experimental investigations of in-plane loaded CLT beams, as very relevant from a practical engineering point of view due to reinforcing effect of transversal layers with respect to stress perpendicular to the beam axis. Experimental results are used for comparison and validation of design proposals from the literature, with the main focus on the shear failure mode III in crossing areas between orthogonally bonded longitudinal and transversal lamination. By using the assumed shear strength values from the literature, analytically predicted shear carrying capacities show good agreement with the experimentally obtained. Although further experimental validation is needed, obtained results indicate that suggested design proposals should be considered in ongoing revision work of Eurocode 5.

As an architectural response to the changing climate, a wind-driven design approach is developed. By adopting the digital design tools, the wind can be integrated into the design process, from the large scale of urban planning, through the form-finding of buildings, as well as designing the texture and roughness of building surfaces. In its more extreme forms, it is even more notable, how the wind flow is shaped and influenced by architecture. Former docks in Stockholm serve as a case study site to test architectural interventions that alter the wind flow on the site. This wind-driven design approach enables the evaluation of the wind performance of various design options, which informs design decisions. Grasshopper, the graphical algorithmic plug-in for Rhinoceros, creates one working environment, where the geometry is parametrically designed, and subsequently analysed in the virtual wind tunnel through the Swift extension for Grasshopper. The Computational Fluid Dynamics analysis results retroactively help decide which of the design options performs the best in the given wind conditions.

This paper discusses results of the adaptive membrane device compared to the model created in FEM software. The numerical model was created according to factory parameters of this device. The adaptive membrane device has to be properly set up, than the device is loaded by load piston with saddle and the adaptivity of this device consisted of two actuators used as anchor rods and another two anchor rods are fixed. The actuator is realised as a hydraulic piston. Based on the results obtained by these measurements and the load results in the numerical model, the comparison was evaluated in the conclusion of this paper.

The use of blended binders using alternative raw materials is one of the key areas of sustainable development in terms of reducing CO₂ in the atmosphere. This approach reduces the proportion of energy-intensive clinker in cement when satisfying technical parameters. The paper presents a proposal of variants of blended binders with the application of fly ash, blast furnace slag and perlite for their use in building mixtures. The durability of the mixtures is assessed on the basis of testing the frost resistance of mortars. Test specimens were produced according to STN EN 196-1. The samples were subjected to 25 freeze-thaw cycles, and both the flexural and compressive strength were then determined, to express a durability factor. Except for slag as a standard component of blended binders, perlite appears to be a perspective material; it meets a limit for durability factor when used as a 30% substitution for cement, as well as when used in ternary composition with slag. Fly ash showed weak frost resistance, even when used with a suitable perlite.

This article contains a brief information about history of transparent wood, its fabrication process and its physical and mechanical properties. The main goal of this article, however, is to find whether transparent wood is a suitable material for load-bearing architectural constructions. This is achieved by using numerical analysis of I-beam with web from transparent wood (and various types of it) and comparing its results with the same sized beam with web from OSB (oriented strand board) and web from glass, which are both successfully used for such applications nowadays. Suggestions on how to use transparent wood as a load-bearing material are also presented in the article.

To reduce the frequency of man-made disasters it is recommended to use development of deposits systems with backfilling of working space at potash mines. The use of halite enrichment waste in the filing mixture is proposed in order to improve the technical and economic indicators of the mine and the environmental situation in the mining area. The factors influencing the choice of development technology with artificial maintaining of winning area are considered. The advantages and disadvantages of using the technology of the backfilling are indicated. Aspects of preparation of hardening backfill and questions of improvement of its quality by disintegration activation of components are revealed. The possibility of activation of halite enrichment waste used as an inert aggregate in disintegrators is considered.

Innovation initiatives are crucial for any industry because their future growth depends on it. Innovative technologies that can have a great impact on the construction industry, such as building information modelling, automation and robotics, augmented reality, virtual reality, simulation, internet of things were reviewed in this article. In spite of that, innovation implementation in the construction sector has generally lagged behind other industry sectors affecting the productivity as well. The governments are aiming to improve this through increasing the level of investments into manufacturing and innovative research in this area. This article reviews the process of adopting innovative technologies and the reasons why there are obstacles to their implementation. It is expected that integration between machines and humans will enhance human capabilities, allowing them to concentrate on more creative and value added, socially important activities in the future. There is also need of changing thinking in order to transfer the results of these technological studies into production in the construction industry.

The present article deals with the fungicidal properties of cement composites based on Waste Sludge Water (WSW) from a concrete plant (CP). The article compares the ability of standard cement composites and cement composites based on WSW to withstand microscopic fungi Aspergillus niger, Trichoderma nereus and Penicillium glabrum. The results of the tests show that the use of WSW as a substitute for pure mixing water in the preparation of cement composites does not have a significant positive or negative effect on the fungicidal properties of the prepared composites.

This study negotiates with percentage fraction for heating and hot water of various solar systems. Research building of the Technical University of Košice was selected. For this analysis, we used simulation appropriate simulation software, which replicates solar systems and calculates the production of the proper solar system. If we consider DHW solar ratio, the fifth alternative, which includes a combination tank system (heating buffer tank) with an outside heat exchanger and a swimming pool, is the most productive. Nonetheless, in accordance of overall solar fraction, the top choice is alternative 4, which is a mix of DHW tank system with a heat exchanger inside the tank. At the end, the outcome demonstrates that, mix of DHW tank and buffer tank for space heating with a swimming pool, that is alternative 6, seems to be the worst case. Efficient usage of different systems based on renewable energy sources and their applications secures Investigated centre mentioned before.

Large diameters and grain aggregates and/or reinforcing bars can have a negative impact on the strength of concrete elements. Tests of concrete specimens with inclusions under uniaxial compression should contribute to a better understanding of the process of failure of concrete elements. The identification of the unstable phase of the cracking and quantification of the effect of diameters, positions, distances, number and material of inclusions, as well as the relative size of inclusions and matrix on compression strength could provide information for an explanation of the causes of the size effect in compressed structural elements. The introduction of the article provides a brief overview of the problem of concrete structures subjected to uniaxial compression. Attention is paid to the failure mechanisms in the process of loading the test specimens from initial crack formation to specimen collapse. The second part is devoted to the investigation of the size effect of varying dimensions of the test specimens with one or three inclusions.

The adsorption mechanism of nickel on natural Slovak zeolite, a regional low-cost material, was studied in a batch system. The effect of various initial concentrations of metal ions in the adsorption process was tested. The highest adsorption efficiency (almost 70%) was reached at a concentration of 50 mg/L. The lowest efficiency was determined at a concentration of 350 mg/L (approx. 19%). Sorption data have been interpreted in terms of Langmuir and Freundlich isotherms. The Freundlich model with regression coefficient 0.83 better fitted for the batch experiments. The change of pH in equilibrium showed to ion-exchange reaction. The conductivity increases in all cases. Due to relatively low efficiency in higher concentration of aquatic solutions, further research and modification of zeolite is needed.

Road construction requires a large amount of construction materials. During asphalt pavement construction it is natural aggregate and asphalt binder in particular. Their ratio varies depending on whether they are applied in an asphalt pavement as a wearing, binder or base course. Nowadays, pressure of public opinion on responsible environmental behaviour and effective use of financial resources create an optimal space for assessment of building materials from pavement layers. According to the EAPA (European Asphalt Pavement Association) data from 2017 the wearing courses accounted for 90 % of all pavement layers in European Union. In Slovakia their representation is also dominant. While in Western Europe reassessment of existing asphalt layers by recycling technologies has been used to the maximum, in Slovakia the reassessment was out of interest of construction companies. With the arrival of new machinery, legislation amendment and social pressure on responsible environmental behaviour, the strategy of some construction companies in Slovakia is also changing. The reassessment of existing asphalt layers for production of new asphalt mixtures goes to the forefront of the interest. This article summarizes necessary steps to achieve an increase in the re-use rate of R-material by hot-mix asphalt recycling technology in asphalt mixing plants.

Digital and technological innovations that have grown rapidly in recent years have been referred to as the 4th Industrial Revolution or Industry 4.0. The paper comprehensively deals with the description of the 3D printers as part of Construction 4.0 with a focus on transport construction. The aim of the article is description of this issue comprehensively and with the help of SWOT analysis identify weaknesses, strengths, opportunities and threats with focus on the transport constructions. The content is complemented by an assessment of the current situation, indicating the possibility of use in practice.

One of the most common reasons for any construction work requirements is an increased humidity of the building. Increased humidity does not affect only buildings with basement, but also buildings without it, which were not properly hydro-isolated or the hydro isolation was damaged due to aging or to adverse environmental effects. Such situations are solved with designing suitable remediation measures, which necessarily includes drying of damp masonry as well. This almost always includes historical buildings, where protection against groundwater was never planned. Such buildings are usually very sensitive to any physical intervention into construction itself and destructive methods of revitalization are very often completely out of the question, therefore it is necessary to develop methods, which can be used particularly for historical buildings. This article focuses on evaluating effects of microwave drying historical brickwork as well as modern building materials. First, the method of microwave drying is described in general, then we cover the experiment, which was performed at the Faculty of Civil Engineering at Brno University of Technology. The experiment was applied on two pillars made of historical brickwork. Those samples were being thoroughly analysed during the drying process and final outcomes were compared to already existing experiments on modern materials. The goal of this work is to find out, if the method of microwave drying is more suitable for described conditions and also to set such process of drying, which would provide the highest effectivity.

The presented paper compares types of connections mostly used for glass structures. Two groups are recognised and it is mechanical connections and adhesive joints. Bolted connections are mostly used as it is relatively simply to design and to provide, but to be able to create such a connections holes needs to be drilled in glass panes, which leads to discontinuities in geometry, weakening the glass panes and to creation of local stress peaks in the area where the bolt is inserted. On the other hand, adhesive joints don't lead to peak stresses as the stress is redistributed along larger area. Huge variety of accessible adhesives enable the joints to be used in almost each conditions. Main disadvantage of adhesives the change in behaviour over time, manly decrease in strength. Also, mechanical properties are influenced by UV radiation, humidity, temperature, etc. The most common adhesives used for structural glass and their performance is shown and discussed in the paper.

The column is one of the most important elements of the bridge because its destruction can cause a collapse of the entire bridge. The aim of the research is to analyse the blast behaviour of the overpass columns on Croatian roads and highways. Based on the archive documents of design plans the most common cross-sectional shapes of the reinforced concrete column were selected. The literature provides formulas for calculation of blast pressure that depends on the distance of the explosive from the target and the amount of explosive. However, the cross-sectional shape of the column plays a significant role in retaining the pressure and impulse on the column and its distribution by column height and width. This cannot be predicted by theoretical expressions, and therefore a numerical simulation that takes into account the column geometry is required. The columns were modelled in the Ansys Autodyn hydrocode software for a supposed scenario in which an auto bomb was placed below the bridge at a distance of 2 m from the column. Based on the numerical simulations it was concluded that the circular column had the lowest pressure on the surface directly exposed to the blast load. This is due to its roundness and the angles at which the pressure was reflected. In contrast, the back surface of the circular column has the highest pressure of all the analysed columns. Generally, rectangular cross-sections have a higher pressure on the directly loaded surface. For more detailed analysis and experimental testing, a rectangular column (P6) with recesses was selected due to its high pressures on both, the front and back surfaces. Selected overpass i.e. its column was designed using the old seismic regulations and as a part of further research, its blast behaviour will be compared to the column designed using modern seismic regulations.

Towards the end of the 20th century there was a huge boom in the development of solar energy, which led to an increase in the production of photovoltaic panels. The producers assume a lifetime of these panels of 30 years. Today, the life of this photovoltaic panels is ending and a large amount of waste is associated with it. This issue is also addressed by the Council of the European Union, which issued Directive 2012/19/EU on waste electrical and electronic equipment. Photovoltaic panels are included in IV. category "Consumer electronics and photovoltaic panels". This Directive mandates that at least 70% of photovoltaic panel materials must be reused or recycled. This paper presents a review of the current trends in recycling of photovoltaic panels and the possibilities of reuse in cement matrix.

Due to the accelerated development of urbanized areas, the increase of paved and impermeable surfaces, permanent changes in the environment of the city occur. The spatial structure of the city is changing. There are creating significant artificial landscape elements that are not able to absorb rainwater. As a consequence of this unnatural phenomenon in the city was identified a new area pollution source - surface runoff. The formation of surface runoff is affected by several factors. For us, it is important the character of the pollutants in the surface runoff. The paper aims to point out the impact of surface runoff from urbanized areas on the environment. Compare quality parameters of rainwater runoff from different types of paved areas (different types of roof, roadway, car parking). To get acquainted with the legislation covering the area permitted criteria for the content of undesirable substances and the method of their removal.

Pesticides, as one of the main monitored micropollutants these days, are monitored and determined even in the drinking water, because of their toxic effect on the living organisms. Presence of these pesticides in the drinking water is undesirable and, therefore, they need to be removed. Chloroacetanilides belong to the group of herbicides, which are commonly used in agriculture. Their complex structure prevents common biological degradation, so more complex processes are needed. One of the most efficient process for their removal is adsorption on activated carbon. In this article adsorption of certain chloroacetanilides from water for two different types of granular activated carbon is presented. Matrix used for dilution of pesticides was drinking water and the efficiency of the removal of pesticides ranged from 5 to 60 % for the specific sorption materials and pesticides. This research has shown that adsorption material Filtrasorb 400 is far more efficient than Norit 1240.

The current sustainability trends pose high demands on building materials and products. Those with potential to be labelled as an environmentally-friendly product or technology are getting preferred. One of the natural resources with such potential is magnesite, whose resources are widely found in Slovakia. The article deals with analysis of the magnesium oxide board properties as the most popular MgO-based building product. The comparative analysis of magnesium oxide boards with other available building boards (plasterboards, oriented strand boards) is included in the article and especially from the point of magnesium oxide boards' benefits.

Extreme weather changes have been increasing in the recent times also in the eastern Slovakia. Extremely dry periods alternate with above-average precipitation. In the paper the drought indices were evaluated: Standardized Evapotranspiration Index (SPEI) and Standardized Precipitation Index (SPI). Using the non-parametric statistical Mann-Kendall test. The evaluated period was 1960 – 2015 at selected river and climatological stations in the eastern Slovakia. The results showed that no clean significant trends occurred in all evaluated indices and stations.

4D modeling is a part of the BIM (Building Information Modeling) platform. It represents the design approach, when the building is designed not only in space (3D) but also in time (3D + time). The aim of the article is to compare Autodesk Navisworks and Synchro Pro in terms of the conformity with the requirements for creating and using 4D building models. The introduction represents the resource search where the advantages and ways of using 4D modeling for construction and the situation of its applying in Slovakia and abroad are summarized. Besides, the 4D model of the building Water World, created in Autodesk Navisworks and Synchro Pro, is introduced there. In the conclusion, there is a comparison of the tools of this software in user's several points of view.

Hydrologic processes, especially rainfall is characterized for their variability in time and space. These processes are known as stochastic processes. For engineering practice is very important to know the behavior of time series for long period. This paper is focused on spatial-temporal analysis of daily rainfall for Košice station in eastern Slovakia. Time series of daily rainfall from period 1951 to 2018 was analyzed by basic statistical analysis and also by descriptive statistical analysis. Results of basic statistical analysis showed the basic parameters of time series, such as average daily rainfall, maximum daily rainfall or total annual daily rainfall and other basic parameters. Descriptive analysis is used to describe behavior of a time series. Results showed, that time series of daily rainfall in Košice station is stationary, homogeneous and there is no noise in time series, which is good for using this time series in further research

Primarily there are gravel and sand particles contained, which are, together with the surface runoff, discharged through the rainwater inlets into the sewer system. The concentration of such sediments varies depending on the urbanization density and built infrastructure in the site. In the part of cities with increased occurrence of trees and greenery are the sediments mostly of organic origin (leaves, grass, branches, etc.). With fully functional urban stormwater drainage are these sediments collected directly in the drain inlets and during the dry weather conditions discharged by the authorized persons into the maintain truck. In our research, we focus on the quantity of the rainwater runoff sediments in general view while analysing the possibility and methods of utilization of these sediments.

Evolution in the construction industry is constantly progressing. Many applications are currently being developed to track the building's life cycle. Increasing emphasis is placed on managing the entire life cycle of buildings. New technologies are evolving, for example building information modelling. The output of this technology is a building information model. Building information model processes digital content related to the whole life cycle of a building. Developers create information models. These models are then archived to mass repositories such as databases and libraries. The databases contain models that contain graphical information and selected non-graphical information. The main aim of the article is to design and identify the structure of a database, that will be containing graphic models with selected non-graphical information based on the acquired knowledge.

Reducing the industry's impact on the environment is the goal of sustainable construction which can be achieved by using renewable and recyclable resources such as scrap tire waste. Great potential of this waste is found in construction mostly as a partial replacement of mineral aggregate in concrete and mortars, asphalt mixtures and geotechnical works. Previous studies on the selfconsolidating rubberized concrete (SCRC) are mostly concerned with mechanical properties of rubberized concrete. However, in order to allow structural application, it is also necessary to investigate bond-slip behavior of SCRC and reinforcement bars. Thus, in this paper pull-out tests are performed on 24 cubic samples with reinforcement confinement. Three different SCRC mixtures are made, first with concrete without rubber particles as reference mixture, second with 10%, and third with 15% rubber particles and 5% silica fume. The other parameter varied is diameter of steel bars (∅12, ∅16, and ∅20 mm). From the results obtained in experimental investigation, key bond parameters and failure modes of SCRC are compared with bond-slip behavior of self-consolidating concrete (SCC).

The article deals with the identification and evaluation of risks of publicly funded construction projects. The study presents a risk analysis, incl. draft measures to eliminate some of the most serious risks that may affect the completion date and contractual budget. Risks are qualified as the product of the probability of the occurrence of an adverse event and the potential damage caused by the event. Risk identification was based on a list of 30 publicly funded national heritage constructions. The most serious risks from the contractor's point of view were identified as a poor-quality preparation and formulation of the contract agreement, climatic effects and shortcomings in the project documentation. Possible implementation of the proposed solutions to these risks in the construction process can eliminate the contractor's failure to meet the deadline for completion of the construction and exceeding the contractual budget.

The aim of this paper is the numerical analysis of a thin technical textile in shape of hyperbolic paraboloid. It is the membrane structure, which can function only in tension and it is geometrically nonlinear, therefore nonlinear analysis has to be carried out. In this case, the structure was subjected to the dynamic loads effects. Natural vibration was applied as a fundamental dynamic characteristic. All of this results in natural frequencies and mode shapes and deflections. Acquired results describe the dynamic behaviour of nonlinear system. This part of the analysis could represent a first step in the dynamic analysis. To complete the dynamic analysis of the membrane structure, the forced vibrations as nonlinear time history analysis will have to be performed in a future.

This work deals with the creation of a hydrodynamic model of the combined sewerage overflow chamber in Banská Bystrica. As an object on the sewer network, we chose a combined sewerage overflow chamber, because its correct functionality directly affects the quality of the environment in the recipient. Simulations were calculated in the program Ansys Workbench 19.2 – Fluid Flow (Fluent). The basis of the work was the creation of a 3D graphic model. The 3D model serves as a base for flow modeling. The core of the work are simulations in the combined sewerage overflow chamber that should correspond to real flow. The goal of our work is to compare the influence of inflow velocity and flow rakes on hydrodynamic flow.

This paper presents the results of a research into the use of a combination of recycled rubber from waste tires as a 100% aggregate replacement in the production of cement composites. The aggregate was replaced with rubber recycled material in two ratios. At a ratio of 50/50 and a ratio of 40/60 fraction 0/1 mm and fraction 1/3 mm. The test specimens were further subjected to CO₂ effect in a Lamart laboratory chamber, where CO₂ effect was simulated as equivalent to an aging period of 50 years. The presented results show that the effect of CO₂ reduces the strength characteristics of the composite compared to the comparative samples.

Building industry is main contributor to greenhouse gas (GHG) emissions. According to goals of Paris agreement to achieve temperature rise below 2°C a year and then below 1,5°C a year, we need to find where are our biggest possibilities of improvement. Focus of this paper is on residential buildings built in Slovakia. With population growth also demand for apartments rises. With residential building development comes possible place for improvement. That is why main goal of this assessment is to analyse current state of our residential building fond using eToolLCD software and cradle to grave approach. Selected environmental impact of this analyse are, global warming potential (GWP), ozone depletion (OP), acidification potential (AP), eutrophication potential (EP), photochemical ozone creation potential (POCP), abiotic depletion potential of elements (ADPE), abiotic depletion potential of fossil fuels (ADPF) and also use of primary energy resources (PENERT). Assessed residential buildings are first part of larger investigation in this sector.

The paper present the design of the technical flood protection measures on Svitava River in Březová above Svitava town. The current state of the study area was evaluated and determined based on related documents available for public as well as on the personal survey of the landscape. Technical solution as proposal of adjustment of the Svitava River (by composite trapezoid), extracting sediments and designing, stabilization of the bank and construction of the protective floodwall is shown in the paper. The riverbed slopes were fortified with a stone riprap with a sieve of grass mixture.

The goal of this research is to evaluate and find new solution in the area of wooden constructions placed in the treetops, which are interesting mainly due to their independence and amazing view among the treetops, and enable the utilization of the land below the treehouse itself. Treehouses can be constructed as a detached object without having to interfere with the trunk, or anchored into the trunk using special anchoring elements, where compact root system of surrounding trees is essential for healthy grow of the tree. Wood is also a specific natural material, which offers a possibility to create architecturally interesting and modern construction. This article is focused on evaluation of anchoring suitability of these constructions in treetops, evaluation of using these houses for recreational purposes as well as permanent living, effect of climate conditions on suitably chosen wood type and construction of these objects.

Composite steel-concrete bridges are one of the most recent additions to the bridge science. By joining the two of the most commonly used materials it is possible to use their strengths combined. This was firstly presented for composite ceilings. It was assembled by encasing the whole I-beams into the concrete deck. Nowadays, it can also be used for short span railway bridges. Ongoing research at Technical University of Košice (TUKE), Faculty of Civil Engineering, is currently trying to prove the unnecessity of usage of the entire I-beam as well as the entire block of concrete by encasing only part of the beam, the so called perforated steel strip, into the concrete.

The paper maps the current level of knowledge in 3D printing of construction objects. It introduces different approaches to creating wall structures of two world companies dealing with the problem of 3D print. It confronts their solution with the normative requirements for the territory of the Slovak Republic valid after 2021. It also presents proposals for possible improvement of the thermal-technical properties of the perimeter wall, modification of the design of the internal structure and properties of the printed material towards the normative requirements.

The assessment of environmental properties of buildings is now commonly using a life cycle analysis (LCA). Due to the rapidly evolving construction industry, LCA research is carried out in many areas, from building materials and components to overall building system. Life Cycle Assessment (LCA) is a tool used to compare environmental impacts along the life cycle of products or services. This paper presents an evaluation and comparing of two external bearing walls of different material compositions regarding the materials´ total energy consumption within the cradle to gate boundaries. Impact categories were calculated by the software SimaPro using Cumulative Energy Demand (CED) method and applying the Ecoinvent database. A renewable (biomass, wind, solar, geothermal, water) and non-renewable (fossil, nuclear, biomass) energies were under consideration. The composition with brick as a core wall material achieved worse results in all categories than the wall composition with aerated concrete block.

The stability of natural and man-made cavities is a very important topic nowadays especially if it is located under new construction areas. There are a lot of residential areas in Budapest and other cities of Europe such as Rome, Paris, and Cracow with stability problems because of cavities. For stability calculations, the geometry of the cavity, strength properties of the rock mass and joints are needed as input parameters, which can be obtained by field and laboratory tests. The FEM software is effective for stability calculations and with them; it is not so difficult to perform parametric analysis. This paper is focusing on the effect of the thickness of the cellar cover on their stability. The investigation site is in Budapest, Hungary, where there are several cellars cut into porous limestone. These cellars are more than 100 years old and nowadays cause difficulties for the building improvements. The geometrical parameters of the cellars and strength properties were measured. The cover of the studied cellar is around 6.0 m, but other cellars in the area have various cover thicknesses from 2.0 to 9.0 m. Therefore, the paper studied the effect of the cover on the stability to find the relation between the depth and the cellar stability. The modelling has been done by Rocscience software (RS2), using a real cross-section that crosses six branches of the cellar system.