Table of contents

The 13^th International Scientific Conference of Civil and Environmental Engineering for the PhD. students and young scientists below 35 years - Young Scientists 2021 (YS21) under auspices of

- assoc. prof. Peter Mésároš, the dean of the Civil Engineering Faculty of the Technical University of Košice,

- Ing. Andrej Doležal, the Minister of Transport and Construction of the Slovak Republic,

- Mgr. Branislav Gröhling, the Minister of Education, Science, Research and Sport of the Slovak Republic, and

- Ján Budaj, the Minister of Environment of the Slovak Republic,

was held in Štrbské Pleso, the High Tatras, Slovakia on 13^th - 15^th October 2021. The traditional meeting of PhD. students, their supervisors and young scientists working in the field of civil and environmental engineering was organised by the Faculty of Civil Engineering, the Technical University of Košice, Slovakia.

The Young Scientist 2021 offered an international platform for the dissemination of the original research results. It provides a pleasant environment to present a new, great ideas of young researchers and discovered advances in the field of civil and environmental engineering and related interdisciplinary topics. The conference provided an opportunity for PhD. students and young researchers to discussed scientific topics and research results, to share their knowledge and experiences, to collaborate in innovative designs and proposals.

List of Editors, Committees, Review Statement are 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 Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

Type of peer review:

The review process was of an open peer review type. Each article was reviewed by two reviewers. First review was provided by the author, who addressed the reviewer himself and made the revisions in the article before submitting both article and the review form. The first reviewer was asked to be someone close to their research, who could provide helpful advice. Second review was provided mostly by employees of Technical University of Košice. The reviewers reviewed articles close to their research area. They were provided with full articles including the authors names and the authors then received the review form which included the reviewer's name. The authors had then an opportunity to revise the papers and the papers were accepted only after the authors made the changes asked for by the second reviewer in their articles.

In the review form the reviewers were asked to judge the quality of the paper, choosing from options: excellent, good, average, or poor; provide some comments to support their argument and give the authors some notes to help them improve the quality of their paper. For the conclusion of the review form the reviewers had to choose the status of acceptance of the paper, choosing from following options: accepted without revisions, accepted with minor revisions, accepted with major revisions, or rejected. If the paper was accepted without revisions, the authors were then not required to provide any revisions. If the second reviewer decided to choose the reject option, the authors did not have an option to revise their paper and the paper was rejected even if the first reviewer accepted the paper.

• Conference submission management system: CaptainForm

• Number of submissions received: 88

• Number of submissions sent for review: 88

• Number of submissions accepted: 87

• Acceptance Rate (Number of Submissions Accepted / Number of Submissions Received X 100): 98.86

• Average number of reviews per paper: 2

• Total number of reviewers involved: 99

• Any additional info on review process:

• Contact person for queries: Kamila Kotrasová, kamila.kotrasova@tuke.sk

The article deals with the data structure for the purpose of Life Cycle Assessment (LCA) of buildings using the Building Information Model (BIM). Construction industry produces a significant amount of waste and on the other hand the capacities of landfills are almost filled. It is necessary to deal with the effective use of materials that have already been used and have potential to be reused again. LCA is a method that can be used to demonstrate the suitability of proposed materials, structures or buildings in terms of their whole life cycle and its environmental impact. BIM includes, in addition to geometry, the information part. This data can be used for life cycle inventory (LCI) and then for the assessment itself. The aim of the article is to analyse previous approaches and define which data structure is necessary to be obtained from the BIM model for the LCI purpose of a specific material. The proposed methodology of the data recognition and selection is based on data structure of non-graphical database called SNIM, which was developed for the Czech construction environment. The article is also focused on the theoretical background of the newly developed classification system Construction Classification International (CCI).

4D modeling has been actively developing over the past decade along with the progress of BIM implementation. 4D model can provide enhanced early decisions about the space-temporal criticality of work elements. This models is a collection of graphical and scheduling information about an object. These inputs can have different levels of detail (LOD). In creating and using BIM projects, the LOD of datasets is an important aspect. However, to date there is limited research thoroughly investigating the issue of LOD within 4D models. The article provides an overview of studies related to the level of detail for 4D models, and also describes the impact of LOD on the final 4D model.

The article deals with the historic buildings and their insulation. It is generally known that classical thermal insulation of walls from the outside is not permissible due to the cultural value of historic facades. Compared to external insulation solutions, the implementation of internal insulation is more technically complex and faces several risks. In the article is devoted the chapter which deals with the aim of the application of internal insulation in historic buildings. There are mentioned risks associated with the application of internal insulation, which are related to the thermal-humidity behaviour of the structure. One chapter is devoted to faults that may occur after the application of internal insulation. These disorders have a building-physical character and also affect the hygienic criteria of the building. The larger chapter deals with insulating materials suitable for the purposes of interior insulation of historic buildings. The results of a case study from Dublin and Košice are also presented, where the thermal-humidity behaviour of selected thermal insulation materials was investigated. The results of moisture content and surface temperature before and after application of insulating materials are compared.

Thermophysical parameters of building materials are required for calculating the complex heat and water transfer in building structures. It can be performed by modern simulation software such as Wufi, Delphin, Math, Comsol Multiphysics and other. This software is suitable for evaluation of water and heat transport in construction of historical buildings, because it can include the impact of water on material properties, driven rain, ground water, heat and water accumulation and other. The material properties of historical building materials are required for the use of this software. In Slovakia, the most used building material was sandstone. Sandstone from Kežmarok was chosen for this paper, which was used in the construction of historic buildings such as churches and town houses. The method of dynamic impulse transition by thermophysical tester RTB was used to determine the thermal properties of sandstone.

This paper describes the methodology of measuring the sound absorption coefficient in a reverberation room. For its purpose, a measuring set was created combining professional with widely available hardware suitable for acoustic reverberation measurements. For the measurement itself, the interrupted noise method was chosen based on the standard ČSN EN ISO 354. Measurement and evaluation of data take place using scripts written in the Python programming language. An effective measuring set was developed both in terms of operation during measurement and in terms of subsequent data processing, accessing and graphical presentation.

Nowadays, due to the maximum use of building lands, high-rise buildings in the cities are coming to the forefront of construction. A high-rise building is a building that, due to its height, requires a different technical, technological and structural design. Due to the increasing floors of buildings, more and more demands are placed on sanitary installations in terms of hygiene and quality of distribution. With the drainage in a high-rise building, the biggest problem arises in the design of stacks, which must be given individual attention. Foul water stacks must be designed in such a way that the overpressure and negative pressure created in them do not cause the extraction of water from traps and thus the spread of unpleasant smell in the building. Fluctuations in the pressure in stacks are influenced by many other factors, such as the method of venting of the stack, the fitting used on the stack, or the transition of the stack to the drain. When dimensioning stacks in addition to the correct design, it is also necessary to use a suitable system, which significantly affects the investment costs. A properly chosen system can save a lot of money that could arise from excessive dimensions, unnecessary fire protection systems, or anchorages. The paper deals with a theoretical analysis of modern technical solutions that positively affect pressure fluctuations in waste water pipes in high-rise buildings.

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 Advanced building materials, Prefabricated and modular designs 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.

Most buildings of historical and architectural value located in the Republic of Moldova are built of limestone or brick. The facades are decorated with columns, semi-columns and pilasters, balusters, bas-relief, and consoles. The degradation of historic buildings over time leads to the need for rehabilitation and restoration. Often privately owned buildings are repaired with the application of modern materials without taking into account the original materials, without researching the original elements and materials. Authentic decorative elements are replaced by polyurethane foam elements, which due to their easy installation and relatively low cost, can significantly reduce the financial costs of finishing and decorating facades. The interior walls of the brick are covered with plasterboard. The exterior walls of limestone are plastered with cement-based mortar instead of lime-based mortar. In some cases, the walls were covered with polystyrene. All these replacements reduce the architectural and historical value of the buildings lead to the loss of their authenticity. In order to preserve the value of historic buildings, it is necessary to use local materials. This research examines the possibilities of using limestone both for the rehabilitation of masonry and for the restoration of the decorative elements of buildings built in the XVIII-XX centuries.

The Fourth Industrial Revolution (4IR) introduced positive changes to some industries, while for most construction industries it is still enthusiastically anticipated. The 4IR focusing on the construction industry in literature is known as Construction 4.0. The Construction 4.0 concept is invoked to transform the current ways the construction industry operates while ensuring benefits, such as reduced overall construction projects' costs and duration, improved quality and work safety, etc. Due to the increasing web usage, it is anticipated that the 4IR technologies will achieve full potentials by the uprising of the fifth generation technology standard for broadband cellular networks (i.e. 5G). One of the most important 4IR technologies is found to be the Internet of Things (IoT). In this perspective, a construction monitoring approach, more precisely a model for construction detection and object spatial/time positioning, is presented in this paper. While still in its initial phase, the model was tested and verified in the laboratory environment for small-scale object detection. It was found that the quality of the model will be significantly improved with the use of the 5G network, while the objects' pool, as big data required for the model's deep learning, is highly dependent on the IoT.

This paper compares different spreadsheet-based optimization tools applied to a practical example of a construction site layout problem. The objective of the optimization is to minimize the total time of material transportation by optimal positioning of tower crane and work facilities on the construction site with repetitive operations. Computer programs, such as MS Excel, LibreOffice Calc, and Google Sheets can be applied as modeling tools for a variety of construction optimization problems in addition to their usual functionalities. In this study, LibreOffice Calc Solver, MS Excel Solver, along with other MS Excel add-ins, i.e., OpenSolver, Evolver, and What'sBest, are analyzed. The capabilities of optimization tools mentioned above are examined on the problem of optimal positioning of tower crane and work facilities on the construction site. The results obtained by optimization tools are noted and discussed. The paper ends with conclusions and recommendations for further research.

During construction, there is often a change in contractual terms, either in advance of construction or delayed construction. This phenomenon is due to many influencing factors such as delayed subcontracting, climatic conditions, the surrounding construction site, the quality of project documentation, the solvency of the investor, the expertise of the general contractor, etc. The aim of the paper is to assess the planned and actual construction of reinforced concrete monolithic structural elements using tower cranes. The subject of the paper is to state the expected method of implementation in time and how the construction proceeded. Milestones for accelerating and slowing down construction, analyzing their causes and proposing future measures will be presented. Data are obtained by measuring real buildings.

The article deals with the analysis of time consumption for the construction of an extensive green roof. Also, it deals with the construction of several extensive roofs in terms of time and then sets a new standard hour for the construction of an extensive green roof. At the end of the article, it is said how it would be possible to speed up the construction of extensive roofs or in some cases simplify it.

The construction industry is a dynamic manufacturing sector whose major problem is occupational safety and its management. There are various information and communication technologies or applications that can improve health and safety status. Their use gives every company management a great advantage to become more competitive in the construction trade. The presented article deals with smart phones and related applications as a type of technologies that can be easily used to improve health and safety performance in our conditions. The aim of the article is to present the advantages and benefits of this technology for increasing safety on construction sites. The presented results confirm the trend of efficient processing of the obtained information using ICT technologies. They intensify the safety management process and help staff to handle unpredictable dangerous incidents and contribute to the successful management of the whole construction site.

In the last decade, the construction industry has been going through a technological revolution known as Construction 4.0. This progress has brought digitization, automation, virtual reality, 3D printing and prefabrication to production. Prefabrication is the basic solution of most Modern Methods of Construction (MMC), thanks to which construction is faster, safer, better quality and with a lower impact on the environment. MMC design solutions can include volumetric, panel, hybrid systems, parts and components bat also on-site innovative technologies. From the point of the sustainability, material solutions of MMC are also very important and open the potential for their innovations. The aim of this article is to explore the possibilities of higher use of composite materials and mixtures, preferably with an emphasis on more environmentally friendly and recycled materials.

In general, we can call the carbon footprint as emissions of gases that affect the Earth's climate, while being used by humans. The impact of construction, building materials, structures, or the overall life cycle of a building on the environment is great. Sustainable architecture is gaining more prominence, using reduced carbon footprint. Today's construction industry is increasingly moving towards sustainable construction, which is constantly being formed. The great weather fluctuations that take place from day to day are forcing us to reduce our greenhouse gas emissions. The global warming potential GWP (global warming potential) caused by these greenhouse gas emissions is increased to carbon dioxide CO₂ and expressed as carbon dioxide equivalent CO2_eq. Using GWP we can determine the carbon footprint of a product. The aim of this paper is to change the three compositions of the perimeter walls using LCA analysis (life cycle assessment) and to choose the composition that has the best carbon footprint and is therefore more advantageous. The need for a sustainable built environment is urgent due to its positive impact on the environment.

The present study investigates the presence and removal of target organic micropollutants in a large Swedish wastewater treatment plant designed for nutrient removal including activated sludge, trickling filters, nitrifying moving bed biofilm reactors (MBBRs) and post-denitrifying MBBRs. A total of 28 organic micropollutants were analysed, at concentrations ranging from few ng/L to µg/L, in the influent and effluent of the different biological reactors in two sampling campaigns. The observed micropollutant removal efficiencies of the wastewater treatment plant varied from insignificant (< 20%) to high (> 90%) between compounds. The activated sludge reactor, being the first in line, contributed to most of the removal from the water phase. Additional removal of a few compounds was observed in the biofilm units, but most of the persistent compounds remained stable through all biological treatments.

Urban flooding and combined sewer overflow in city, or town areas represents potential risk in environmental, economic, or social aspects. The goal of this study is to process and evaluate efficiency of individual solutions to reduce occurrence of flooding in urban areas caused by intense rainfall events. The known conventional solutions are stormwater chambers, or storage drains. The new trend in reduction of stormwater drainage into combined sewer system are parts of blue-green infrastructure. Blue-green infrastructure represents environmental urban infrastructure which consists of sensitively selected urban vegetation combined with ingenious hydrological elements of urban city drainage. The study also deals with experimental usage of decentralized real time control, based on a gossip-based algorithm of moveable gates in sewage network. Experiment was proposed for drainage system of the city of Cosenza in Italy. Evaluation will assess application value of individual proposed solutions for the reduction of combined sewer overflow for Slovak republic and its urban cities, or towns.

The most discussed topics in the 21st century at the global level are climate change, carbon neutrality, digitization and globalization. They have impact on the lives of all people, the quality of the environment in which we live, the health of the whole population, the development of cities and urban areas, the development and direction of industry and its new technologies, and last but not least, they shape humanity to which they are giving direction. To meet our 2030 goals, we need to know where we are now from carbon footprint point of view and where CO₂ production comes from around us.

The paper deals with CFD simulation of a real combined sewer overflow chamber using Ansys fluent software. Simulations are created for various structural modifications. Within the results, the hydraulic parameters of the individual are evaluated with a proposal for optimal operation of the given relief chamber.

The article deals with the possibilities of intensification of mechanical-biological wastewater treatment plant with intermittent Flexidiblok type activity with denitrification. This wastewater treatment plant is located in a municipality with more than double of the equivalent population than the capacity of the wastewater treatment plant and therefore does not meet current legislative requirements. Proposals for the intensification of the wastewater treatment plant offer the possibility of reconstructing the existing wastewater treatment plant to the required capacity or rebuilding this wastewater treatment plant to a pumping station. Part of the article is an economic-technological comparison of both proposals.

Over the last few years, climate change is one of the most important phenomena in the 21st century. It is bringing significant changes and negatively affecting the environment. This unwanted phenom causes substantial changes in climatic and hydrological characteristics that are manifested mainly in urban agglomerations. It affects extreme weather changes, the occurrence of natural disasters, water shortages, and other phenomena threatening the quality of the environment. On the other hand, there are measures close to nature based on the sustainable development of urbanized areas. Their main goal is to reduce the volume and rate of runoff and the concentration of undesirable substances in rain runoff from urban areas. Therefore, in the research study, we focus on evaluating published studies that have adopted the SuDS practices. We will compare the effectiveness of SuDS measures in capturing flood peak from surface runoff, pollution loads, and their impact on water quality. The result of this study could help select SuDS measures depending on the need to address the problem in the river basin.

Climate change is a global phenomenon. The more frequent occurrence of dry periods, which last longer but also extreme rainfall, needs to be reduced for better water management. During the dry season, the quantity and quality of surface and groundwater decreases. Water is important for agriculture, agriculture and ecosystems. This study was focused on the occurrence of trends in daily flows in the Hornád basin at selected hydrological stations for the period 1960-2011. The Mann-Kendall trend test is used to evaluate trends in hydrometeorological time series.

Thermal baths in Slovakia are producers of wastewater, which hides considerable energy potential. The wastewater from the thermal pools has often exceeds the maximum permissible value of the temperature of the wastewater discharged into the water recipient. As a result, there is undesirable damage to the environment, which results in sanctions for the operators of these facilities. Our aim is to present the concept of a single- and double-step heat recuperation system of waste pool water using applications of various types of heat exchangers or heat pumps. The aim of this application is to ensure a suitable temperature to the discharged waste pool water, efficient use of the energy potential of the waste water and saving of primary energy in the form of geothermal water, thus extending the life of the entire system.

Waste management is one of the essential areas that everyone in the world should carry about. Waste collection and treatment help to reduce the risk of the spread of various diseases. Municipal waste is waste produced in households by the population. Municipal waste can be sorted into other components, such as plastic, paper, glass, metals, and biodegradable waste. These types of waste are in most urbanized areas collected separately. The sorting level offers accurate information about each urbanization, to what extent its population is involved in separated waste collection. The paper focuses on analyzing the waste collection system in the selected locality and will examine the local waste sorting level development during the last few years.

Paper presents a proposal of the flood risk assessment methodology. The theoretical background is based on the multi-index conceptual models, which consists of three layers -objective layer, index layer and indicators layer. The fulfilment of the layer is based on the Reports on the course and consequences of floods in the territory of the Slovak Republic.

As in most Slovak cities, there is a combined sewer network in the city of Trnava. Therefore, combined sewer overflow (CSO) must be provided on these networks in order to mix rainwater and sewage water. The purpose of these CSO's is to reduce the amount of rainwater supplied to the treatment plant and to discharge part of the rainwater to the recipient. However, these waters contain various contaminants, including coarse solids, fine suspended solids, and solutes. Due to this, reduced water quality was recorded in the Trnávka recipient. This reduced quality is also due to the increased number of reliefs as prescribed by Government Regulation n.269/2010. The aim of the work is the analysis and selection of unsuitable relief chambers that do not meet the given limits. Hydrodynamic simulations are performed on these chambers, which demonstrate the need to reduce the amount of rainwater or reconstruction of CSO's.

A number of articles have already been published on energy recovery from the sun using solar panels and their environmental impacts. However, in this article, we assess the impact of solar panel technology, and use separately obtained data based on the disassembly of a specific photovoltaic panel into discrete parts. The aim of this article is to list all the environmental impacts of this panel per unit of energy produced and at the same time to focus primarily on deciphering the energy intensity of individual phases of the life cycle of photovoltaic panel production. An analytical method of Life-cycle assessment using the environmental software version SimaPro 9.0.049 with an integrated Ecoinvent 3 database was used to determine the environmental impacts. Throughout the work, we focus on the data obtained, which shows that the process of photovoltaic panel production itself is very energy-intensive, especially in the phase of photovoltaic cell production and solar glass production. In other phases, which is the production of individual parts of the photovoltaic panel, its use, and subsequent recycling, they do not contribute so much to the overall energy balance. In the environmental impact assessment, the most affected aspects were human health, followed by climatic change, resources, and the ecosystem quality came last. In all four of the above categories, the influence of the photovoltaic cell production phase was determined to be dominant.

Design rainfalls are essential parameters in designing and assessing combined and stormwater sewers and are still used today. They create idealized intensity profiles with statistically determined parameters. Their gradual development is based on the development of computer technology, measuring instruments, and measurement campaigns' progress. However, climate change is causing changes in precipitation events' characteristics, so it is important to focus on reassessing them and adapting to current conditions. The paper summarizes the knowledge about the development of design rains to reveal their potential for the future.

This paper is to present the chosen methodology for research and thus approach the design process through biomimicry. The described methodology is applied in parasitic architecture research, focusing on developing the experimental design of architectural structure using artificial intelligence and thus approach and support the central hypothesis of the work -the effort to create self-designing and self-growing / developing architecture. Furthermore, the paper outlines the ontology as a model of knowledge, a source of data for the developed software © PAF A.I. and a source of inspiration influencing the final design of the proposed architectural structure. The way in which such an ontological resource is processed for research purposes and how it participates in the final design within the verification and validation of the whole conceptual design is also described. Besides, the paper explains why the ontology in question is essential and what was established as its content.

Membrane structures are becoming popular because of the potential usage in structures with higher aesthetic claims. For the roofing of these structures, different textile materials are used. These special materials offer an alternative to conventional roofing materials and allow, besides its lightweightness, also a possibility to roof a difficult floor plan and big span. When designing such a construction, there are some challenges related to the properties of the specific material. In order to exploit the full potential of textile membrane materials, it is necessary to choose an appropriate material model for numerical modelling, which takes into account its nonlinear behaviour. The two most important material characteristics needed for characterizing the behaviour are Young's modulus of elasticity and Poisson's ratio. Since the material is orthotropic in most cases, it is necessary to test the material in two directions; therefore, these characteristics need to be obtained from the biaxial test. This contribution is focused on the research of the methodology of biaxial tests and test instrument assembly procedure, which will be used for the following testing of textile materials.

In this article, a numerical analysis of various types of I-beam with web from transparent wood was performed and compared with standard OSB board and glass web. Properties of transparent plywood which have not yet been produced from new kinds of transparent wood samples were calculated using laminate theory. Results of analysis show, that the transparent wood composites prove to be very promising structural material for future use within the load-bearing structures of buildings. The best properties showed the transparent wood composites infiltrated by cellulose nanofibers (CNF) and polyvinyl alcohol (PVA).

Construction projects are characterized by low productivity due to many wasteful activities in construction processes. Wasteful or non-value-adding activities result in quality and profit loss in many construction projects. Consequently, construction needs more effective strategies for process innovation at all stages of the construction project life cycle. Analysis of the current state has shown the possibilities of improving construction processes through the implementation of technologies, methods and procedures of lean construction. Such improvements can help increase the efficiency and productivity of construction projects. Therefore, it is necessary to promote more effective construction waste management by identifying the causes of non-value-adding activities during the construction phase, and apply the gained data to eliminate wastes during the planning phase. The paper presents the most appropriate technologies and methods for collecting data on non-value-adding activities.

Perforated steel strips are used as reliable shear connectors many years. During this time, many different shapes of the openings or recesses were developed to improve the durability and resistance of the shear connection. Behaviour of these strips were mainly verified by experimental research, but many parameters could not be measured. Numerical analysis provides not only easy and fast way of testing the behaviour of specimens, but also the possibility to improve the geometry of the strips. Modified steel strips can be deeply investigated in simulations and subsequently verified by push-out tests in laboratories. The combination of these two methods can bring the spectrum of the information that can complexly describe the behaviour, durability and also the weak points of the shear connection, especially in case of the new or modified shape.

Describes the procedure of experimental measurement of the runoff coefficient C, both of individual layers and the entire composition extensive green roofs. Experimental measurements make it possible to determine the reference behaviour of runoff characteristics, namely runoff coefficient C, with emphasis on the simulation of the real behaviour of extensive green roofs. The aim is an elementary description of the structural and physical behaviour of extensive green roofs. For the needs of experimental measurement, the dimensional and shape limits of test specimens are described, the conditions for conditioning of individual specimens, the boundary conditions of execution and individual steps of the experiment. Then is specified the method of evaluation and subsequent verification of measured data. The result of the experimental measurement is the amount of drained water from the tested specimens of the extensive green roof at time t, which shows a nonlinear behaviour. From the set of measured data, it is then possible to predict the behaviour of extensive green roofs in real conditions and to determine the runoff coefficient C of the tested specimens. These data represent reference values for the subsequent design of sub-elements and structures of buildings.

Electroconductive composites are modern materials that are commonly used in many industries such as construction industry and machine-building industry. For example, these materials can be useful as sensors for monitoring changes in constructions, shielding stray currents from electrification networks, shielding electromagnetic radiation in operating rooms, cathodic protection against moisture or overvoltage protection of buildings. The topic of this post is the research of electrically conductive silicate composites with graphite-based fillers. In this research will be tested composites with different ratio and types of graphite and monitor their electroconductive properties like impedance, and physical-mechanical properties like compressive and tensile strength. The post describes basic properties and interactions of silicate electrically conductive composites with graphite fillers. It was found that by adding 10 % wt. graphite into silicate composites, impedance is reduced by 50% and compressive strength by 40%. The flexural tensile strength depends mainly on the roughness of the particles, where the coarser flaky particles transfer the load better and increase the strength while very fine graphites reduce the flexural tensile strength. Furthermore, it has been found that very finely ground synthetic graphites are most suitable for achieving low impedance of composites.

This work deals with the monitoring of changes in the mechanical properties of solid fired bricks depending on their dampness using non-destructive methods. Decreases of first natural frequencies by the resonance method and increase of passage times of ultrasonic waves depending on increasing dampness are monitored. The elements were firstly fully saturated and then slowly dried so that it was possible to record the values of the first natural frequencies and the passage times of the ultrasonic waves at different dampness. It is not possible to record values in all dampness, so the measured values were interpolated by regression models. A polynomial of the 2nd degree seems to be the most suitable. Dampness corresponding to the minimum natural frequencies and the maximum passage times of the ultrasonic waves were performed on these regression models. This research is the first step in determining the durability criteria for ceramic products, especially solid fired bricks. In the future, durability criteria should help in the reconstruction of historic buildings to assess whether the element that will be exposed to the weather is durable or not. These tests are completely non-destructive, which means that the tested element can be subsequently used in construction.

This paper deals with the research of a new silicate-based repair mortar modified with selected secondary raw materials. The aim of this work is to develop a chemically resistant material suitable for use in an extremely aggressive environment of sewers. The monitored parameters include key physical-mechanical characteristics, resistance to sulphate ions and to the attack of aggressive biogenic sulfuric acid. Chemical resistance was tested by simulating the exposure environment in laboratory conditions, according to the methodology of DIN 19573. The obtained results show that by suitable modification of the reference mortar it is possible to maintain the values of physical-mechanical characteristics and improve the chemical resistance of test samples.

This paper deals with the study and development of polymer-based adhesive with high filling ratio of secondary raw materials and waste materials. The goal of this paper is to develop adhesive mortar with the highest filling rate of secondary raw materials and waste materials as possible while preserving very high physical-mechanical properties, including flexural and compressive strength, pull-off bond strength and abrasion resistance. High-temperature fly ash, waste slag and waste packaging glass are used in this paper as fillers. The resulting mortar shows high physical-mechanical properties, including high abrasive resistance and very high bonding strength to a large variety of building materials including concrete, steel, glass, and tiles.

The presented work focuses on the predominant microorganisms on the interface of cementitious materials and soils from different localities. Soils contain microorganisms that can affect the underground concrete structure positively or negatively. Different types of microorganisms are adapted to the environmental conditions depending on the quality and quantity of elements in the soil. Methodology of the work was based on screening 5 selected localities in the Košice city from which soil was taken in the nearness and in the contact with the concrete structure. These samples were further analysed. In this paper the presence of bacteria in the soil around the construction is confirmed.

This article presents the results of the possible use of construction waste and rubber granulate as a filler substitute for the production of cement composites with thermal insulation properties. It describes the individual components of the materials necessary for the designing of recipes and their properties. The article presents the thermal insulation properties and strength characteristics of the designed recipes of non-traditional cement composite after 7, 14, 28 and 90 days.

The focus of this paper is to explore the possibilities of optimizing 3D printed elements produced by FFF/FDM technology based on bending tests according to ČSN EN ISO 178 (64 0607) with variations in the settings of the printing itself. The principle of FFF/FDM is the printing of a continuous fiber made of thermoplastic material, which is applied by machine to the previously printed fiber. There are many combinations of possible print settings, and one of them is the geometry of the inner density with variable density. Their resulting maximum values of the achieved load were then compared with the weight (amount of material used) and printing time. The result is a comparison to achieve economical printing with the greatest possible load capacity.

The detailed analytical and experimental investigation of the fracture behaviour of quasi-brittle materials is an endeavour which has been ongoing worldwide for many years. Such materials are usually characterized in terms of their mechanical fracture parameters, which are determined based on the evaluation of quasi-static fracture experiments. One of the most commonly used building materials with a quasi-brittle response is concrete, which is most often based on a cement matrix. It is sometimes also necessary to characterize concrete included in existing structures. In this case, test specimens are obtained by core drilling, and the investigation is conducted with the requirement to maximize the number of parameters obtained while minimizing the number of test specimens drilled from the structure. This paper focuses on the mechanical fracture parameters of core-drilled specimens taken from a selected concrete structure. Tests were performed on cylindrical specimens with a chevron-notched stress concentrator in the three-point bending configuration in order to determine modulus of elasticity, fracture toughness and fracture energy. Subsequently, theoretical compressive strength was estimated and tests for the determination of compressive strength values were performed focusing on dependence on the slenderness ratio, i.e. the relationship between the compressive strength and the length to diameter ratio of the cylindrical specimens. In relation to the obtained mechanical fracture parameters, selected specimens were analysed and three-dimensionally characterized via high-resolution X-ray computed tomography.

Alkaline activated binders showing enhanced piezoresistive properties have recently attracted increased interest in research of their application in smart self-sensing components. This study is focused on metakaolin geopolymer mortar doped with 0.05 and 0.10% carbon nanotubes, a conductive filler that effectively increases electrical conductivity without considerable deterioration of mechanical properties. Self-sensing performance of composites incorporated with electrodes and attached strain gauge was tested during different regimes of compressive loading cycles with continuous monitoring of strain and resistivity. Although the differences in sensitivity and repeatability were observed, all samples including the reference material have shown good response to applied loading.

Even though earthen architecture is recognized as cultural heritage in Croatia, most of existing buildings are in deteriorated and heavily damaged state. Until today, there has been no conducted research on earthen architecture in Croatia, nor was any preservation act proclaimed. Therefore, the purpose of this research is to learn more about behaviour of traditional earthen architecture to highlight the importance of sustainable building. For that purpose, earthen houses in Eastern Croatia, mainly Slavonia and Baranja area, were studied and in-situ samples were collected. In order to learn about characteristics and composition of mixtures, five samples were tested. Results gathered within this research will be the first step towards creation of national standard for designing rammed earth structures. In scope of future research, authors are planning to use verified recipe in making of walls that will be tested for seismic resistance.

The article deals with a laboratory preparation of triclinic modification of clinker mineral tricalcium silicate. A substantial part of the article is devoted to the technology and technique of firing a sample of tricalcium silicate, which would in the future allow the study of the development of the crystal lattice structure of this clinker mineral at short isothermal durations, in the order of minutes. As part of the research, a small high-temperature experimental furnace was designed and constructed. Based on the results, we can express the suitability and applicability of this furnace for the study of the formation of triclinic tricalcium silicate at short soakings.

During the past years, due to the increase in the number of people and the increasing degree of industrialization, the amount of by-products produced, the so-called waste materials are becoming larger. As this problem grows with age, attempts are being made to find answers to the questions of how to use waste material purposefully in order to reduce the problem of disposing of large quantities of this type of material. One way to reduce the accumulation of waste material is to use it in construction materials. This literature review paper presents the research of the area dealing with the influence of fly ash application on properties of clay brick. The application of fly ash at various percentages in relation to the mass of clay and the influence of fly ash at different firing temperatures are studied.

Cold-formed structures are a separate type of metal structures and require more complex mathematical models in comparison with massive profiles. The development of main theories was described. A new type of buckling is also taken into account - warping, which is characteristic only of cold-formed bars.

This paper is focused on the numerical analysis of an adaptive membrane structure, the model of which was created on the basis of experimental device in the lab. It was researched out the effect of asymmetric use of actuators on the membrane structure without structural loads. Results of the article describe the behaviour of numerical model. The results gained from numerical model will be compared in the future with the results measured out from the experimental device.

An influence of the bi-material interface between a steel substrate and a thin protective layer applied through laser cladding was investigated. A range of elastic properties and thicknesses of the layer were considered to cover the behaviour of a short crack in the selected materials such as bronze, nickel or cobalt alloys. The special case of the crack terminating directly at the interface was investigated, which is connected to the necessity of application of generalized approaches of linear elastic fracture mechanics. The results contribute to better understanding of fracture response of selected materials and to a more reliable decision on choosing a proper material of the protective layer.

Cement fiber boards (CFB) are special group that are used in a wide range of structural civil engineering. For the correct design of a cement fibre board structure, it is important to define their material and elastic constants, which are usually determined by destructive tests. The paper deals with a definition of a suitable method of loading for the determination of basic materials and elastic constants of cement fiber boards reinforced with organic fibers loaded in the mid-plane. The publication compares and evaluates load tests by three-point and four-point bend.

Glued laminated timber beams are nowadays used as load-bearing beams of large-span structures that operate in various humidity conditions. Typical application areas are aqua parks with high humidity as well as market halls with low humidity. It is related to the possibility of the occurrence of cracks typical for the drying of wood, even with such controlled conditions of production technology as glued laminated timber. Cracks visible on the used girders raise doubts as to the safe operation of the structures. The subject of this paper is the computational simulation and the evaluation of the influence of beam delamination on the mechanical response of the structure. The attention was established on a typical two-span beam of constant height with a slight slope to the horizontal. The numerical analysis was carried out for three variants of the location of potential delamination of different scope. The beams were modeled as a problem of the linear theory of elasticity in a plane stress state with orthotropic material properties. The calculations were made in the Abaqus software environment. The results obtained in the paper allow to determine the areas in which the presence of delamination or cracks should be considered dangerous from the point of view of the safety of operation. Computational analysis is helpful in assessing the safety of structures where cracks appear. Theoretical considerations are supplemented by an example from engineering practice.

The aim of this paper is the analysis of the modal vibration of the membrane structure. Membranes are defined as structures of the lightweight architecture and they are currently very popular. They have a long history and development, in which they have reached a stage where we can complement them with action elements, also called actuators. These elements can change their length and thus affect a stress state of a membrane, which allows more efficient use. In addition to a static analysis, it is necessary to subject structures to a dynamic analysis, in this case we deal with the natural vibration. This modal analysis deals with the first 5 mode shapes and their dependence on the change in the length of the actuators. This initial calculation will be followed by a forced vibration analysis in the future.

The usual structural analysis assumes that buildings are fixed to the ground. This is not always the case, especially for structures with shallow foundations on soft soils. It was learned from the literature review that neglecting soil compliance in the structural analysis may result in significant structural damage during an earthquake event. The seismic performance can greatly differ between buildings rigidly fixed to the ground and buildings for which soil compliance is considered. Therefore, the main goal of the experiment conducted in the laboratory of the Faculty of Civil Engineering in Rijeka was to observe the dynamic behaviour of a structure on soft soil. The model was experimentally tested using a shaking table. The foundation soil was modelled using local river sand. For parametric analysis, a numerical model was done using the computer software SAP2000. The model was calibrated using experimentally obtained results. A comparison between the experimental and numerical models is presented in the paper.

The paper deals with the level of required prestressing designed for box-girder bridges. Mainly focuses on the development of standards used in the design of prestressed concrete road bridges in the Slovak Republic. The standards for bridge design have been amended several times. A parametric study was performed on a model post-tensioned concrete bridge with a box-girder cross-section. The bridge has three-span with a main span of 50 m and end spans of 40 m. The study compares the normal stresses caused by traffic load along the length of the bridge according to various standards and technical regulations. The differences in design principles were investigated while the amount and geometry of the longitudinal prestressing of the bridge were changed as required by corresponding standards. The numerical model is considered as a beam element with neglecting of the torsional effects of the load. The parametric study points out the differences in the normal stresses along the bridge according to different design regulations and standards. The aim of the study is to compare level of prestressing according to the historical development of prestressed bridges

Major advantage of fibre reinforced polymers (FRPs) is their high strength and low weight to strength ratio. These are also the main reasons for a choice for this material in the process of design of reinforced concrete structures. Since there is no corrosion of FRP, this reinforcement could be strongly recommended for concrete reinforcement in aggressive environment. Till today there is no sufficient knowledge of long-term behaviour of FRP-reinforced concrete structures. Design codes give low utilization capacity of FRP materials and are not supposed to be correct according to the real behaviour in a few experiments of last decades. Reduction factors limit the mechanical properties in the range from 0.95 for CFRP to 0.5 for GFRP. In the paper there is presented a prepared and today realized long-term experimental study based on four point bending test on simply supported concrete beams reinforced with GFRP reinforcement.

Research in this paper presents a theoretical study of increasing in punching shear capacity of the strengthened flat slab by concrete overlay. The parametric study is based on comparison of three different relevant standards design models and presents results how Eurocode 2 (EN 1992-1-1), Model Code 2010 and draft of second generation of Eurocode 2 (prEN 1992-1-1) take into account strengthening by concrete overlay. A reference specimen is represented by a fragment of a flat slab supported by circular column. Influence of concrete toppings depends on thickness and also on reinforcement ratio. In Eurocode 2 and new generation of Eurocode 2 the increase of punching shear resistance of the slab with concrete topping can be taken into account only by reinforcement ratio and thickness of the slab considering the perfect connection and bond between the original slab and new layer of concrete overlay. Model Code 2010 is based on Critical shear crack theory and the reinforcement ratio in concrete topping was considered in equation of moment of resistance and punching shear resistance is calculated by considering the rotation and deformation of the slab. Estimation of results by parametric study are compared by non-linear model from Atena software.

The aim of this study is to find out how the change of individual parameters will affect the flexural strength of steel-concrete composite beams. The project was focused on the choice of strength of materials and the choice of dimension, specifically the height of the concrete slab and the size of the steel profile. The research aim is to reveal which parameters have dominant influence on the flexural strength and thus facilitate the optimization of the design in practice.

In concrete structures, we identify deformation fields of nodes with applied concentrated stress, which are accompanied by a change in the density and shape of force trajectories. These changes are caused by the presence of large grains of aggregate and/or reinforcing bars (inclusions) in the concrete, clumps of grains of normal size, or the presence of a cavern around the grain of the aggregate. These internal imperfections are among the important parameters that affect the failure process of concrete test specimens, and thus the initiation and development of cracks in concrete and can have a negative impact on the strength of concrete elements. This paper deals with the influence of the number of inclusions in their symmetrical arrangement on a series of test specimens of three different sizes, which are subjected to uniaxial compression. Attention is paid to the selection of a suitable standardization parameter, which will consider the different quality of concrete test specimens

In the area of drying damp masonry, we already know the discussed method of microwave drying. This method is indestructive, which is why it is considered to be used for listed heritage buildings. Even though there was much research done already on this topic, we are still missing answers for some questions regarding particular methodological procedures. This contribution is focused on the impact of time intervals of microwave drying on the final result of masonry drying. The experiment was done on historical masonry of CPP and on ceramic masonry. Two laboratory samples were made out of each type of masonry, to which we applied microwave drying in different time intervals. Difference was in both time of drying and time of pauses between them. The aim was to set an ideal interval of drying.

This article deals with the punching capacity of a flat slab fragment supported by an internal atypically elongated column. Based on the results of this analysis and the application of Critical Shear Crack Theory, the reliability of two design models was determined. The CSCT model is a mechanical model where the shear force transferred by concrete in shear crack can be determined by accounting for the roughness and opening of a critical shear crack. The crack width is proportional to the slab rotation, which was obtained from a nonlinear program Atena and from experimental test and shear capacity was obtained by integrating the shear strength along the control perimeter. The aim of this analysis was to compare the application of CSCT in non-linear analysis and experimental test to point out the significant difference between obtained results, which shows the importance of experimental tests realization. Non-linear analyses provided unsafe results. Contrary the currently used EC2 model provided safe results when reduction of the control perimeter was applied. The best results were obtained in a combination of the CSCT model with measured rotations of the slab specimen.

Composite materials became more popular and commercially available as reinforcement for concrete elements. Fibre Reinforced Polymer (FRP) bar is an excellent thermal and electrical insulator with high tensile strength and low weight. These assumptions make them a possible substitution for steel reinforcement. Moreover, GFRP is not responsible to corrosion for that are suitable for structures with high humidity and unfavorable environment. GFRP is easier to handle due to its low weight. Also, it has electromagnetic neutrality. But it has some disadvantages. It has a low modulus of elasticity and sensitivity to elevated temperatures. Another drawback and uncertainty with designing is the impact of an alkaline environment, which decreases the long-term strength of GFRP bars. This paper describes a pre-experiment study of concrete elements resistance. The analysis is performed for a cross-section of 200x150 mm for a short concrete column with steel and GFRP reinforcement. The study compares P-M diagrams for steel reinforcement and GFRP reinforcement with different reinforcement ratios. Other characteristics such as tensile strength and modulus of elasticity must be considered to design the GFRP reinforced concrete element. The study also considers the contribution of GFRP reinforcement in compression. The analysis has shown, the shape of interaction diagrams of steel and GFRP reinforcement are significantly different.

Bridge weight-in-motion (BWIM) system is a method, that provides to identify axle weights. It is a non-destructive method, which allows not only to identify the axle weight, but it can show current shape of the structure, so it has a great potential. There are various methods to do measurements for this system. Mostly, accelerometers or strain gauge are used. Signal noise has significant effects to the results. It could be resonance of the bridge, wind, defect at the support system, defect at the roadway, etc. It is necessary to filter all this effects, to get clear data. There are many ways to do the filtering. Digital filters allow it. Sometimes, this type of filtering could remove important data about the crossing of the vehicle. It could generate inaccuracy of the whole system and create major errors to identified vehicles. It is necessary to find the optimal way, to keep important data and remove all dynamic noise. This paper will investigate the previously mentioned problems. Measurements will be accomplished on a small-scale model of the bridge. Vehicle will be crossing over the bridge, while the bridge will be awakened to the first vibration shape and other frequencies, that will have a great impact to the measurements.

Historical masonry arch bridges still form an important part of Croatian transportation network. There are approximately 680 masonry arch bridges and culverts currently being used for railways and roadways. Many of these bridges are relatively old (more than hundred years in most cases) but still in usage. Increasing vehicle load and speeds as well as deterioration due to anthropogenic and environmental influence have highlighted the need for reliable assessment of their service condition and regular maintenance. The aim of this study is to provide a review of existing masonry arch bridges in Croatia. Firstly, a historical review of bridges is given showing the time period in which they were built, indicating the materials and design principles used for their construction. Next, bridge typologies are presented as well as their detailed analysis of geometric characteristics for brickwork bridges. Finally, a short review of damages and their impact on serviceability of bridges is given. This review presents masonry arch bridges in Croatia and the need for reliable method of assessing their service condition in order to provide proper maintenance, repairing and retrofitting.

Continuous shear connectors in a shape of dowels are one of the newer shapes of composite steel-concrete bridges. In this article results of push-out tests of such a dowel with geometry designed at Faculty of Civil Engineering, Technical University of Kosice are presented and compared to the previous research.

Two types of push-out tests were carried out at the Centre of Research and Innovation in Construction, the Technical University of Košice - one at a composite based on steel continuous shear connector and the second one at the same connector, however made of glass-laminate material. For further research, the material characteristics of the material used needed to be found. In this article, the material tests performed as well as their results are presented.

This study investigates convenient methods of determination of temperature gradient of slender structures in time. Correct determination of temperature along the height of the cross-section takes a key role in defining the temperature loading of slender bridge structures. A proper definition of temperature loading is crucial for structures such as stress ribbon because of their sensitivity to temperature change in terms of geometrical changes of the structure. Correct determination of the temperature gradient is important during long-term geodetic monitoring, which might be used to prove the correctness of computational models of bridge structures. To approximate heat transfer in cross-section, a test specimen with temperature sensors installed along the height was formed and continuously monitored. The accuracy of the retrofitted temperature sensors was also investigated. The temperature at the surface of the specimen, solar radiation and wind velocity were used as input data for heat transfer analysis. The measured values from sensors situated along the height were subsequently used for verification of performed heat transfer analysis on volume computational model in the software Ansys Mechanical.

The subject of this research is the analysis of shear connection effect on the fiber glass reinforced composite beams. The research contains the detailed analysis of materials like concrete and fiber glass reinforced composite. The shear connection has been tested by the experiment of push out test run in the Centre of research and innovation in construction of Technical University of Košice. The shear connection has been tested on two types of connectors used on composite beams. The main idea of this research is find out whether it is possible to use the alternative material, which should substitute the steel. The aim of research is to design a type of connector for fiber reinforced composite materials or another composite materials developping in the world of material engineering. The part od research is devoted to the FEM analysis.

Nowadays, due to high external temperatures, the topic of cooling is very actual. However, cooling buildings is energy intensive. Therefore, it is necessary to focus on more than one method of cooling. We can say that cooling can be provided in 2 ways. By building services and by architectural design. For existing buildings, we cannot change the shape and orientation of the building. But we can change the composition of structures. Green architecture is often mentioned in this area. Therefore, the aim of this research is to interconnect these two areas and determine the influence of vegetative roof on the radiant cooling and heating systems. This connection shows us how the design will affect the HVAC systems.

The trend is to reduce the energy intensity of buildings. Thermal energy storage (TES) is the biggest challenge for buildings. It is a technology that supplies thermal energy by heating or cooling a tank, which then serves for the system in the building. Comparison of hitherto known systems ATES, BTES, PTES and research TTES. The most important factors for the accumulation of thermal energy are capacity (the energy stored in the system - depends on the storage process, the medium, and the size of the system), power (how fast the energy stored in the system can be discharged and charged), efficiency (the ratio of the energy provided to the user to the energy needed to charge the storage system. It accounts for the energy loss during the storage period and the charging/discharging cycle), storage (how long the energy is stored and lasts hours to months), charging and discharging (how much time is needed to charge or discharge the system), and cost (refers to capacity (€/kWh) or power (€/kW) of the TES system and depends on the capital and operation costs of the storage equipment and its lifetime).

Not long ago, the sustainability of buildings was not taken as a design priority, although it was considered to some extent. The required level of sustainability has risen sharply in recent years, buildings are becoming more self-sufficient, environmental friendly and greener. Towards more attention to green sustainable alternatives in architecture, new solutions for sustainability began to be sought, such as the use of vertical and horizontal surfaces of the building for green facades, the use of roofs for roof greenery, as well as introduction of greenery into building in the form of green walls. Along with the introduction of greenery into the interior comes the new necessary technical solutions, thinking about the overall green wall with respect to the indoor environment and building itself as well as new possibilities of using rainwater, beautify the interior, improving the air etc. However, it is important to perceive a green wall as a living element that must be sustainable, and this is what this article is about. The article focuses on the green walls from the point of examining the available information on this subject in domestic as well as in foreign sources. The results of this article can help to improve understanding of various green walls from different perspectives and compare their view on the green wall in terms of sustainability. The paper helps designers and researchers to orientate in the given topic to create an overview of the different options of the current greenery systems.

This article aims to present an innovative way of designing objects called A method of shaping an energy-efficient building envelope based on natural patterns. The method uses currently available technologies in an unusual way. Digital photogrammetry data are inserted into a process of designing envelope structure of future objects. In the process of construction, this method counts on the use of all the advantages of 3D printing technology. This combination of the use of relatively innovative technologies in the process of design and construction of buildings opens up new possibilities for the design of the building envelope. Consequently, new building envelope shaping options create space for more efficient use of the energy savings associated with the building envelope shape as a building shape factor. The final design solution of the proposed building takes inspiration directly from the environment in which it is to be situated. Final design takes inspiration of its shape from the environment in which it will be built as a future object. As a result, the building works harmoniously and in accordance with the environment in which it was designed. This creates a pleasant ecological environment for its inhabitants and the surrounding area.

The construction of shaft intake structures in Slovakia has increased. The shaft intake structures overcome significant vertical height over short horizontal distance. In their front horizontal section, the water flows with free surface, then in the vertical section the flow changes its direction and character to a pressurized flow. The flow of water in these shaft intake structures is therefore very complicated. A hydraulically suitable design of the intake structure is associated with achieving the required parameters of the small hydropower plant (SHPP), but due to the reduction of project costs, the shapes of shaft intake structures of SHPP are often not correctly hydraulically designed. One of the important aspects is the distribution of flow velocity of these intake structures. Uneven distribution of flow velocity causes negative effects on turbine performance. Therefore, the investigation of the effects of shaft intake structure design on flow velocity distribution has been realized. The velocity field at a shaft intake of a small hydropower plant was investigated on a physical model in a hydraulic laboratory using the PIV (Particle Image Velocimetry) method. The PIV measurements were realized for different shaft heights and proved negative effects of the design on the flow homogeneity in the turbine intake.

For a long-term retention of water in aquifers and its subsequent use in drier or heavier demand periods, the Managed Aquifer Recharge (MAR) techniques are studied and implemented in 4 pilot areas of the DEEPWATER-CE project. In Slovakia, the pilot study is situated in the Rye Island. A calibrated MODFLOW model is used for a prediction of groundwater level changes caused by the Recharge Dam MAR. Results of the simulations showed that the increased groundwater level caused by the realization and operation of three proposed weirs affects the volume of water infiltrated to the aquifer but does not cause the flooding of the adjacent area.

Climate change is affecting every aspect of the world including water resources and water scarcity. Drought is one of many big problems associated with climate change that could occur all over the world. Moreover, hydrological drought is one form of drought that relates to decreased river discharges, below-normal groundwater level, declining the area of wetlands and low water level in lakes or reservoirs. In this study, an assessment of hydrological drought in Gidra river is conducted to characterize dry and normal hydrological years according to Slovak Hydrometeorological Institute (SHMI) Methodology. Furthermore, making benefit of machine learning and artificial intelligence in this field is applicable now, as data of many types are being recorded every day. Deploying machine learning algorithms for the purpose of drought prediction is one way to regulate many operations of water management to prevent irrigation problems. By catching patterns through historical data and deploying machines to learn from those patterns, it is possible to use the values of daily average discharges for January, February, March, and April to correctly predict the hydrological situation in Gidra river whether it is dry or normal, knowing that normal situation refers to wet or normal hydrologically assessed years as the optimal goal in this study is drought assessment and prediction of Gidra river.

The subject of the contribution is to clarify the causes of anomalous development of water levels in some observation objects of the Rozgrund dam. To clarify the anomalous development of the water levels, a detailed analysis of the development of water levels in all observation probes built on the dam, the water levels in the reservoir and the daily total precipitation was performed. An important knowledge is the amplitudes of fluctuations in water levels in observation probes and in the water levels in the reservoir. The calculations of correlation coefficient, expressing the relationship between water level in individual boreholes and the water level in the reservoir are another step in assessment of anomalies. Based on the knowledge obtained, it was possible to assess the degree of the influence of the water level in the reservoir on the development of the water level regime in observation objects. At the same time, it was also possible to detect the existence of other effects influenced the water levels in the probes, such as the leakage into their surroundings caused by precipitation or the impact of waters flowing from hillslopes.

Today, the study of the city's sewerage network is an important part of the life of the city and the environment. Ensuring optimal living conditions not only for oneself, but also for other participants in the environment should be a priority for a person. Today we can face various problems that complicate the operation of the city sewer network and can cause detrimental effects on the environment. To prevent this impact on the environment, you first need to understand the cause of this impact, and then look for a solution. Wastewater is a pollutant of rivers, lakes and the water system in general. Wastewater is formed in connection with human activity, the appearance of rainwater, as well as under the influence of industrial enterprises. The purpose of the article is to develop the management of wastewater flows within the city sewer network to ensure the highest quality water clarification and minimize environmental harm.

The aim of this paper is to present the possibility of revitalizing the disappearing wetland of Céne in eastern Slovakia. Due to climate change and anthropogenic interventions in the natural landscape, natural habitats are currently extinct. Wetlands are one such habitat, of which the Céne wetland is a very good example. Wetland Céne is a place of occurrence of rare species of fauna and flora. The paper proposes and evaluates the method of revitalization of the wetland by subsidizing the water in the wetland from the river Tisa through the proposed dam culvert. The paper also evaluates the technical measures that need to be implemented and the economic aspects of this solution.

Asphalt mixture is a building material with many advantages. Therefore, it is most used in road construction. If the asphalt mixture is laid with the prescribed technology, it can withstand load effects to long-term. It is necessary to take samples that will be subjected to laboratory measurements. There are several laboratory test, for example measurement thickness of the asphalt mixture layers, the aggregate fraction, quantity of binder in the mixture, determination of air void in asphalt mixture layers. Samples taken directly from the construction site are subjected to laboratory tests. This article focuses on one of the laboratory tests and it is determination of air void in asphalt mixture layers. The determination of air void in asphalt mixture layers is test in detail, because this effect has influence on the deformation properties of asphalt mixture layers. Therefore, it was necessary to model of air void in asphalt mixture layers with different degrees air void. On this purpose was use program Abaqus. The results were plotted. This graphs showed that increasing the air void in asphalt mixture layers has effect on the expansion of deformations. This can lead to faster pavement degradation.

Sharing modes of transport in Kraków: in the context of the transport policy of large cities, it is worth noting sharing as an increasingly common method of transport. The policy of sharing: cars, scooters, bicycles and motor scooter has become an important way to complement public transport. The aim of this paper is to analyse the available shared transport modes used by Krakow residents and their impact on the environment, over the last few years. The increase in popularity of available shared transport solutions is due, among other things, to their availability and relatively low cost of use. This solution is a response to the needs of modern cities and has a positive impact on the environment.

Roads exposed to continuous and heavy traffic often shown sight of damage which particularly extend to the underlying layers of roads. Due to the advantages of less raw materials and fossil fuel consumption, lower carbon footprint and the capability of pavement performance improvement enormous effect have been done in the western countries over the past decades. Thanks to the efforts of some construction companies in Slovakia our focus in this paper on the innovation technology of cold-in-place recycling is given. The presumption of success of this innovative technology is the introduction and use of the set of a powerful and interconnected machines. This technology allows the repair of deep defects, rutting and fatigue failure, which cannot be done by surface treatment with significant reducing the impact on the environment, material, and economical savings. Moreover, it enables the repair of deep defects, rutting and fatigue failure, which cannot be done by surface treatment. To promote the widespread application of cold-in-place recycling technology in practice and to monitor the progress of developments, this article has examined and discussed the basic aspects of the use of this technology based on laboratory analyzes of recycled material.

Soil and rock properties are essential inputs for the design of geotechnical structures. But unlike man-made materials, the determination of the characteristic value is not simple, mostly because of the large space variability of the soils and rocks. In many cases, the large spatial variability makes it difficult to collect sufficient ground samples for further laboratory testing so that many tests are performed directly in the field. In Slovakia, the dynamic penetration test (DP) is, among others, a quite popular field test for soil investigation. From the measured data, it is possible to derive relative density (ID) shear (φ_ef) and deformation (E_def) parameters of coarse-grained soils. There are many available correlations between the DP results and geotechnical parameters. Therefore, it is necessary to choose the most appropriate one as it considerably affects the final evaluation. This paper shows the assessment of geotechnical parameters of coarse-grained fluvial soil from the DP results and presents the statistical determination of its characteristic values, which are furthermore compared with the nominal values used in Slovakia.