Table of contents

The International Scientific Conference CIVIL ENGINEERING CONFERENCE 2022 (CEC 2022) on the occasion of the 45^th anniversary of the establishment of the faculty under auspices of assoc. prof. Ing. Peter Mésároš, PhD., the Dean of the Faculty of Civil Engineering, Technical University of Kosice, and Ing. Andrej Doležal, the Minister of Transport and Construction of the Slovak Republic, was held in Košice, Slovakia on 7^th - 8^th June 2022.

The conference was organised by the Faculty of Civil Engineering, the Technical University of Košice, Slovakia. It issued topics of civil and environmental engineering for colleagues, graduates, teachers, researchers, students, and the professionally cooperating public.

List of COMMITTEES are available in this pdf.

All papers published in this volume have been 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 Publishing.

• Type of peer review: Double Anonymous

• Conference submission management system: Morressier

• Number of submissions received: 97

• Number of submissions sent for review: 97

• Number of submissions accepted: 94

• Acceptance Rate (Submissions Accepted / Submissions Received × 100): 96.9

• Average number of reviews per paper: 2

• Total number of reviewers involved: 100

• Contact person for queries:

Name: Kamila Kotrasová

Email: kamila.kotrasova@tuke.sk

Affiliation: Faculty of Civil Engineering, Technical University of Kosice, Slovak Republic

Transparent wood is a relatively new material, the manufacturing starts with removing the lignin from wood veneer and infiltrating the delignified wood by a polymer thereafter. Transparent wood usually proves better mechanical properties than original wood and polymer. The article presents the potential use of transparent wood in bearing structures. The transparent wood could be used as I-beams structures, box beams, trusses, or folded structures. A spatial folded structure was numerically analyzed. Various types of transparent wood or transparent plywood were used. A comparison with commonly used materials, such as glass and other wood-based materials were made. The comparison shows that transparent wood has great potential in the use as a structural material. The plywood made from transparent wood veneer with the alternating direction of wood fibers acts as a laminate and allows a biaxial load transfer, which can be successfully used in a thin plate of the spatial folded structure while maintaining relatively good transparency.

This paper deals with the review and categorization of form-finding techniques. Their utilization in architectural design, consisting of realized as well as theoretical concepts, is studied. Employing experiments, parametric and simulation-based designing, or artificial intelligence in the design process provides a platform for novel, architecturally unique, unexpected structures.

The article shows the results of an experimental measurement of the air pressure change occurring due to the passing of an electric high-speed train. These data are then used to verify the elaborated simulation model of a high-speed train aerodynamic impact on the infrastructure facilities. According to the outcomes of research, the proposed model is quite reliable and suitable for further application.

With the current trend of construction of high-rise buildings in urban agglomerations, ensuring watertightness of their facade structures exposed to the effects of high-intensity wind-driven rain is coming to the fore. Laboratory experimental testing of water impermeability of elements of building envelope structures and their joints is performed in the process of preparation of the facade implementation in accordance with STN EN 1027: 2002 in rain chamber equipment. Due to the fact that the quality and functional properties of the finished facade are significantly influenced by the assembly technology and work discipline in its implementation, successful testing of the facade and its components in the rain chamber may not guarantee the watertightness of the finished facade. For this reason, the investor has the opportunity to check the finished facade in terms of its hydrodynamic safety and reliability by a functional test of its watertightness according to the standard regulation STN EN 13051 Curtain walling - Watertightness - Site test. The article describes in detail the new technological device for the implementation of the in-situ watertightness test of the facade, the measurement methodology, including its functional verification on the facade of the high-rise administrative building Nivy Tower in Bratislava.

Slovakia is a rugged country, a significant part of which consists of mountain areas. Construction activities in these localities should consider specific natural conditions, while taking into account economic issues. In these cases, the efficient way of construction is the use of aerial work, so the execution of constructions using helicopters. However, compared to conventional technologies, helicopters are limited in their work by several factors, which are mainly related to their movement in a three-dimensional environment (atmosphere). The aim of this article is to show how the choice of fresh concrete mixture is related to the work of helicopters, to design a suitable mixture for the currently valid Slovak requirements and to test it in laboratory conditions. The selection of the mixture is narrowly specialized for the construction of reinforced concrete footings of cableways, which are typically realized in mountain areas. The results showed that by using a suitable superplasticizer based on polycarboxylates, it is possible to ensure the required workability of fresh concrete within 180 minutes. However, the condition must always be met that the onset of setting of the used cement does not occur earlier than 180 minutes. Longer workability time can be achieved by adding a retarding additive.

This study deals with determination of the share of building materials impacts in whole building life cycle considering longer life span. Our aim is to investigate differences between widely used 50-year life span compared to100 and 150 years. Purpose of this study is thinking about aging residential building fond in Slovakia and their future. It is needs to be said that highest peak in building development occurred between 1955 till 1983 when prefabricated residential buildings were mostly made. These buildings take almost 38% share of all buildings finished till 2020 and youngest of them are almost 40 years old in 2022. It is needed to re-evaluate 50-year life span in all cases. Based on this situation this work focuses on residential buildings located in Slovak republic. For the assessment One Click LCA software was used, boundaries were set for cradle to grave. The functional unit was chosen 1 m² of the total floor area in duration of determined life span. Results are presented for modelled scenarios which investigates changes in global warming potential impact category.

In this paper, research on the topic of Resistance of a sealed joint subjected to tensile stress at different temperatures is presented. Tensile stress is one of the physical effects acting on conventional structures. This research specifically deals with the sealing of problematic material. Aquapanel cement board is chosen as the problematic material. This board has a large amount of fine dust particles on its surface, which prevent the sealant from adhering properly to the base material. Next, two sealants and the appropriate primers are selected. The sealants used were selected based on the manufacturer's recommendations on suitability for use in sealing cementitious materials. From these three components, the Aquapanel cement board, the sealant and the primer, test specimens are made, which are tested according to the valid European standard. The results of this test are carefully recorded and further analysed. Based on the results of this test, it is possible to recommend both tested sealants for sealing cement materials that are exposed to tensile stress at different temperatures.

Flood damages come immediately with flood events. There is a wide range of models and methods that can be used for its evaluation, which bring satisfactory but not exact results. The rate of flood damages estimation can differ significantly from the real damages measured after the real flood. The current paper presents three methodologies for assessing flood damages including INSYDE model, AGRIDE-c model and RASOR platform. These methodologies are compared and their suitability for application to available data is analysed. The available data includes the number of damaged elements due to flood as well as the extent of the flooded area. Results of comparison shows that the INSYDE model and RASOR platform could be possibly modified and applied to the available data, but there are significant changes and further analysis needed. The analysis of selected methods shows the data that are needed must be first obtained from other source, then modified, and then could be applied. But we do not have the same data, so the further studies need significant changes.

Climate change and sea level rise (SLR) represent many challenges for coastal areas such as coastal erosion and saltwater intrusion (SWI). This study aims to highlight the effect of climate change and SLR on Egypt's northern coasts and present appropriate adaptations. A number of techniques for adapting with climate change and SLR have been presented. Two numerical models have been used for simulation PLAXIS and 2D-FEST. The results showed that SLR will affect a number of cities on Egypt's northern coasts and the Nile Delta aquifer will be affected by SWI. A number of scenarios have been applied to adapt with climate change and SLR. Precast Diaphragm Wall (PDW) is used to protect Egypt's northern coasts from SLR. The results showed that PDW is applicable and cost efficient. The cost of building PDW along the north coasts is about 1.0% of the likely losses due to SLR in 2100. However, to control SWI into the Nile Delta aquifer a number of measures have been presented and discussed. The results revealed that using treated wastewater to increase the recharge to the Nile Delta aquifer combined with decreasing the abstraction from the aquifer could help in protecting the aquifer from probable SLR.

This paper is aimed at the possibility of recycling the cement bypass dust (BPD) and ground granulated blast furnace slag (GGBS) into a normal hardening hydraulic road binder in accordance with standard EN 13282-2. 10 wt.% addition of BPD as potentially hazardous waste formed during the clinker production by burning alternative fuels was used into cement mixtures. Binder mixtures' composition was designed according to the recommended sheet of Slovak commercial product (DoroCem). The main constituents of the experimental hydraulic road binder mixture were Portland cement clinker, ground limestone and GGBS. Effect of additional component of BPD on behaviour of fresh mixtures and properties of mortar specimens after 56 days of hardening was studied. The results prove that only one of the tested mixtures (BM2) with the lowest SO₃ content and clinker but with the highest amounts of GGBS, ground limestone and alkalis (Na₂O + K₂O) met the standard requirement for initial setting time for tested fresh mixtures. The higher values of compressive strength found for all hardened specimens are most likely related to the formation of the hydrated and geopolymer products in the binder system. Based on these conclusions, BM2 could be used as hydraulic road binder.

In construction, the emphasis is currently on high energy efficiency of buildings. A ventilation system ensuring the indoor air quality has a significant share of energy consumption in buildings. Open fire sources, such as gas stoves and candles result in the air pollution in the indoor environment that causes more intensively operation of ventilation systems. The aim of this research is to quantify the pollutants arising from the burning of a randomly selected wax candle that commonly is used in households. Experimental measurements were performed with a special regard to carbon dioxide (CO₂) production. The weight loss of the wax during the burning of the candle was has been measured and subsequently the production of CO₂ was estimated using a chemical formula. Based on the amount of CO₂ produced, the intensity of air exchange using ventilation system has been calculated to achieve the required quality of the indoor environment. The calculated air volume flow rate required to remove the pollutants generated during the burning of the candle is in this case approximately 54% of the air volume flow required per one person.

This paper investigates the phenomenon of the size effect of quasi-brittle lime-based material. This research aims to confirm the existence of a size effect on a homogeneous material - test specimens of mortar, which are subjected to uniaxial compression and provide additional knowledge to explain the causes of the size effect. This paper deals with the analysis of the results of experimental tests of mortar specimens without inclusion and with one centrally located steel inclusion. Two series of tests with different slenderness and size were prepared. The results of the experiment showed that the compressive strength of the test specimens decreased with increasing specimen size. The larger interface area between the inclusion and the mortar matrix negatively affected the compression strength.

Indoor air quality is a key aspect of people staying inside buildings. Combustion processes have been identified as one of the most important sources of pollutants in the indoor environment. Proper HVAC design must account for all sources and variations in their intensity, such as also the burning of candles, which produce not only increased amounts of carbon dioxide as a result of the combustion of the organic matrix, but also often dangerous organic substances. On the other hand, the candle burning represents an energy source as well. This article deals with the study of thermal decomposition of selected candle material using methods of thermal analysis - thermal gravimetric analysis (TG) and differential scanning calorimetry (DSC). The wax material analyzed was identified as a mixture of palm stearin and paraffin. During the candle wax material heating, the energy up to 772.6 J per 1 g of material can be released in dependence on the heating rate.

The aim of this article is determination of seismic response of cylindrical steel tank situated at Al Hoceïma city in Morocco. When a storage facility containing liquid starts moving due to earthquake loading, the fluid filling exerts additional hydrodynamic pressure on storage facility solid domain. The seismic effect of a liquid–filled storage facility converts the contained liquid into and equivalent spring-mass system representing impulsive mode together with convective mode of vibration of the storage facility - liquid system. The seismic response of cylindrical steel tank subjected to seismic loading was calculated by using the elastic response spectrum for locality Al Hoceïma city in Morocco. The rules of Eurocode 8-4 were respected for documented seismic analysis of storage facility containing liquid.

The source of hot water production for the investigated storage tanks are solar collectors. Solar collectors provide recharging of underground storage tanks all year round. Due to the large active area of solar collectors - 225 m2, there are also large tanks for long-term accumulation. Accumulation tanks are in 3 sizes with a total volume of 160 m3. With regard to the size of the tanks, the mode is switched between the tanks according to the season. The tanks are made of a reinforced concrete packaging structure and are stored under the terrain of the Center of Research anf Innovation in Construction (CVIS laboratory).

The research presented was on the table more years and covers the cooperation of the University staff with City of Bratislava binding with the activity of private company. The base task was how to change the tremendous destruction of modal split in Bratislava, which growing on the side of private car usage. Results of couple of traffic studies show, that how could be this change re-define the current traffic behaviour and create for the new area new functional interest and certainly the new quality of relationships of land use. The system solution is in the amplification by a capacitive new tramway network. In the conditions of Bratislava, we need to change the behaviour of the people in the mobility over the area of the Capital city of Slovakia. The task was to solve the problem in Bratislava agglomeration as well. The solution is shown as a part of the integrated public transport services possibility to operate regular all days' mobility problems in the city and not only to cover the rush hours. This article is an overview of 5 years work of traffic engineers and planners to keep clear systematic approach and solutions with developers and municipality administration.

Since 2011, the change in climatic characteristics has emerged as one of the three most common environmental risks today. Global warming forecasts warn that by 2100, our planet could warm by an average of 3.5 to 7.5 °C. In Europe, over the last 140 years, the average annual air temperature has risen by about 1.5 °C. In Slovakia, it was an increase of 1.7 - 1.8 °C on average. The consequences of these changes in road construction are immediate and intense and require adequate adaptation measures.

Long-term measurements of climatic conditions in Slovakia were the basis for assessing changes in average daily air temperatures in individual seasons. With the design of road pavements and calculations of pavement structure models, we have also tested road construction materials - especially asphalt mixtures. The results were used to correct the values of input data, design criteria, as well as in measures to reduce the impact of changes in climatic conditions.

The paper focuses on the characterization of the climatic conditions in Slovakia and the changes reflected in the design of the road constructions; also provides some insights into the solution of partial problems in the field of asphalt pavement and cement concrete pavement.

In this article are presented the author's experimental studies for determining the dynamic modulus of elasticity of concrete in tests of reinforced concrete beams at the age of concrete 1926 days. For two years the reinforced concrete elements were indoors, and for the next more than three years they were left outdoors, exposed to external atmospheric influences. The results of the measured velocities of P-longitudinal and S-transverse waves generated by piezoelectric transducers are presented. The research used a combination of two modern non-destructive methods in the study of concrete - ultrasonic pulse velocity and ultrasonic pulse echo. The dynamic Poisson's ratio and the dynamic modulus of elasticity of concrete are determined on the basis of the measured velocities of the longitudinal and transverse waves. The measurements were made respectively by means of portable instruments Proceq Tico and Pundit Live Array Pro of the company Proceq. The obtained results are compared with the theoretically calculated modulus of elasticity according to BDS EN 1992-1-1:2005/NA:2015.

The aim of the paper is to introduce and evaluate the yield of cost as tool of measurement and comparison in construction economy. Yield on cost evaluates the ratio of investment or development costs to project income over given period. Evaluation of effect time indexation and discount rates on comparative metrics is required. As result the base equation is proposed to use in comparing economic performance of peer project across development industry

The aim of the paper is to present partial outputs from continual measurement of light conditions in office environment during common work activity. The volunteers worn head mounted dosimetric devices – the Lightwatchers, to collect individual and realistic data in contrary to fixed photometric measurement devices. The outputs confirm that the natural activity of office workers has a great influence on recorded illuminance levels. It shows an overall decrease of light levels recorded on vertical plane in facial area when compared to standalone fixed sensors. Since the total amount of the light received through the eyes is important for a proper entrainment of our biological system, an adjustments for office´s lighting design needs to be taken into consideration.

The paper deals with a static reanalysis of the existing ice-rink bearing steel structure which proves all the bearing members of the object after additional loading by new roof coat. In addition to experimental measurements carried out to diagnose the bearing roof steel structure and its elements needed for static assess the structure's current state, pressure coefficients in individual parts of the structure were defined by means of ANSYS software and consequently used in static analysis of wind effects. According to the static analysis results, the repair of initial state was designed and realized, with designing of details needed to be modified. By means of ANSYS software, the detail of pin joint support of laminated lattice-girders was 3D-modeled with volume elements. The deformation-stress analysis of the mentioned detail was also performed by considering of elastic-plastic material with linear hardening.

The future of future generations of humanity is conditioned by the decisions, actions and behavior of contemporary society towards the surrounding nature. The current critical state of the environment caused by the human factor forces one to think about a change in thinking in relation to ecology. Progress in this direction and the pursuit of a sustainable way of life is also felt in the construction sector. Modern wooden buildings are an environmental alternative to buildings made of energy-intensive materials. This type of construction is currently experiencing great success worldwide and is already part of the standard of living in many countries. Progress in this ecological way of construction has been recorded in recent years by the construction industry in Slovakia, but in its development it is progressing much more slowly than other countries of the European Union. The potential behind the development of wood-based structures is currently not fully exploited and it is therefore necessary to pay increased attention to research and innovation in the timber construction sector. The work deals with a survey of consumer preferences in the field of wooden buildings.

In urban agglomerations, even in our conditions, typical environmental risks are acoustic risks caused by traffic of all kinds. In the case of tram transport, a high-amplitude tonal noise was identified when passing a tram vehicle in a directional curve, which is perceived depending on the emerging frequency as a short-term sound, which emotionally manifests itself as an unpleasant squealing. As a result, the health of the population living in the vicinity of the tram lines is endangered. The described problem forced the authors to look for suitable methods for determining the acoustic risk. The "Risk Management" system was chosen as a suitable tool, the logical step of which is to quantify risk. The results used in the risk assessment process were based on specific measurements at selected locations around the tram line in the city of Kosice. The aim of the risk quantification process is to design the basis for selecting the optimal way to reduce / eliminate acoustic risk to a socially acceptable level.

Fracture in materials with inclusions is considered in the computational model of this contribution which allows prediction of crack propagation. The inclusions cause that cracks may appear inside the materials or along matrix-inclusion interfaces. The presented model can treat them both using two internal variables in a fashion of damage mechanics so that fracture is a consequence of the damage. The first variable is defined at the interface represented by a thin degradable adhesive layer so that an appropriate stress-strain relationship can be obtained as in cohesive zone models. The second variable is defined in the structural domains as a phase-field fracture variable which causes elastic properties degradation in a narrow material strip that forms a smeared crack. Both these damaging schemes are expressed in a unique quasi-static energy evolution process. The numerical solution approach is thus rendered from a variational form with a staggered time stepping procedure related to a separation of deformation variables from the damage ones and using non-linear programming algorithms implemented together within an own MATLAB finite element code. The numerical simulations with the model include simplified structural and material elements.

The current construction technologies are often characterized as ineffective, with long construction times, heavy structural weight, increased financial and labour cost, and environmentally unsustainable. Innovative construction methods, including modern lightweight panel systems, are characterized by low weight (this affects not only transport characteristics but also the production, such as easier handling of the panels), faster construction time, the guaranteed quality due to industrial production in a factory, economic efficiency and many other benefits. The presented study examined the potential of efficiency and performance of four variants of lightweight construction panels in the context of the required essential properties of prefabricated construction elements, as well as in comparison with the variant of "heavy" prefabricated concrete panel system.

The issue of imperfections is mostly related to additional internal forces. However, our understanding of imperfections is associated with the change of structural behaviour. In our case, the most likely indicated effects of imperfections are the reduction of the contact area, and the unreachability of the required overlap length. The behaviour of these slip joints depends on sufficient contact between sliding parts. The contact area is affected by the imperfections of the manufactured steel tubes. This contribution presents the manufacturing tolerances and subsequently, it describes the incorporation of them into the design of the slip joint. Furthermore, the article presents a comparison between the ideal numerical model and model with imperfections involved. Moreover, this numerical model is verified by experimental measurements. The results indicate that imperfections have a significant impact on the slip joints. In our comparison, the effect of imperfections is about 120%.

The paper describes a theoretical study and exploration of authors in the field of biomechanics. The lung parenchyma is focused, and its elastic behaviour under the physiological mechanical load, pressure change during breathing. Anatomical view to the human respiratory system generally is introduced first together with a more detailed description of the alveolus. Then the appropriate theory is elaborated, aimed on the mathematical model establishing, the finite element method is chosen as the resolving tool. The computational implementation is realized in multi physical software based on the finite element method.

Practical application of expansive concretes in reinforced concrete structures needs the rational design model for assessment the early-age stress-strain parameters of self-stressing concrete elements under any restraint conditions during the expansion stage. Various strategies are used to calculate the restrained expansion strains and self-stresses but, in most cases, disregarding the elastic-plastic behaviour of expansive concrete at early ages. It's noticeable that in case of bi-axial restraint conditions both the elastic-plastic parameters of expansive concrete and the influence of restraint in orthogonal directions should be taken into consideration. To achieve a reliable solution a design model for estimation the restrained expansion strains and self-stresses in self-stressed structural elements under bi-axial restraint conditions (2D MSDM) at expansion stage has been developed. The proposed design model is based on the MSDM for the case of uniaxial restraint arrangement. The validation of 2D MSDM was confirmed by the experimental results of expansive concrete elements under 2D confinement carried out by authors as well as obtained by other researchers.

The paper describes a scientific project that is solved at the authors' workplace. The scope of the project is the analysis and experimental research of fragments and details of building envelope structures designed for demanding conditions. It will be a question of determining the physical properties (thermal, humidity, energy, aerodynamic, light and other) of building structures and the internal environment of buildings, for demanding conditions. In this case, it is the conditions in the design process - the assumption of environmental conditions (climatic conditions of the exterior, conditions of the interior, such as humidity), or the effect of other conditions in the implementation and use of the building. Measurements will be performed in buildings (in situ) and in experimental conditions in the laboratory. After verifying the boundary conditions, the tools leading to virtual reality will be used in the compilation of experimental models with the help of simulation programs for the effects of individual influences. The task of the project is to analyze these influences and solve them in mutual cooperation, i.e. in the interconnection and action of individual influences (heat, light, energy and others).

The evaluation of existing bridges is an important process and source of information within the bridge management system. Except for the load-carrying capacity represents the basic evaluation parameter, it moreover expresses a relevant and decisive parameter for the transition of actual road traffic. The paper presents the continuation of an already published analytical study aimed at comparing the effects of traffic load produced by different load models on road bridges. There are presented calculated load-carrying capacities for model cases of bridges with an upper deck with eight alternative spans and six different cross-sectional arrangements. On each of them, multiple load models simulating the effects of traffic were considered, while a certain predefined part of the considered load represented the required weight of the vehicle defining the load-carrying capacity of the respective bridge. The discussion is mainly focused on the pitfalls and possibilities of correctly defining the dependence of the weight of the vehicle representing the load-carrying capacity from the traffic load consideration schemes themselves, which are mostly defined by design codes.

Industrial halls have a very high energy consumption due to existing production processes, heating, cooling, lighting. To reduce energy consumption, it is necessary to make a number of technical modifications to the structure itself, or the interior. The industrial sector is one of the largest consumers of energy. One way to save energy is to take advantage of daylight. Natural daylight is an important part of our daily lives at home and at work. Providing natural daylight to the work environment is essential for the personal well-being, work efficiency and safety of the users of this environment. This paper deals with the evaluation of visual comfort in an industrial hall. Visual well-being is assessed on the basis of physical calculations. These were implemented by the RADIANCE simulation program. The lighting calculation was performed for both the cloudy sky and the clear sky. The program also qualified and quantified the brightness distribution. Potential sources of glare have also been identified.

An old office building located on the Garbiarska street, historic part of Kosice city, east of Slovakia was selected because it represents a brownfield and necessarily requires reconstruction. This study is aimed at the analysis of two design alternative solutions to underline the architecture of the reconstruction in terms of sustainability criteria taking into account the significance of the history of the city and its surroundings. Performed SWOT analysis considered strengths and weaknesses of restoration, opportunities and threats, shows that the most suitable is considering a restoration strategy in terms of preserving cultural heritage, at the same time restoring the building in the concept of green architecture. It is more than necessary to prioritize this renovation strategy over an economically viable renovation while maintaining the inappropriate height of the office building. This early analysis confirms the significance of the revitalization of territories in connection to the improvement of quality of life, the enhancement of the historical value of the locality and the creation of new economic opportunities.

The basis of creation and development of the theory of creep of reinforced concrete is based on unscientific principles taken from systems of classical mechanics that do not correspond to this theory. Linear systems with stationary properties (inertial, dissipative and positional components) are used to describe the properties of aging concrete. The replacement of constant coefficients in classical models is carried out: instead of these constant coefficients ai variable coefficients are inserted, which are functions of time - a_i(τ), a_i(τ), i=1, 2, 3, 4. From such the replacement, the integrand function of the theory has lost its physical meaning. Errors in structural calculations are 300-500%.

Number of engineering tasks concerning water management as well as hydrological research require sound knowledge of temporal and spatial changes of soil suspension density, specific surface area and distribution parameters of soil texture in dispersed soil phase. This contribution is based on the hypothesis that there is a dependence between density of soil suspension, specific surface area of soil particles and distribution parameters of soil texture d(10), d(50) and d(90). The contribution analyses the results of an experiment investigating the temporal and spatial course of soil suspension density, specific surface area of soil particles and the distribution parameters of soil texture d(10), d(50) and d(90) in soil suspension. For the research purposes, the methods of laser diffraction, sedimentation analysis and statistical correlation analysis were used. The results of the experiment are displayed graphically. To enhance the visual representation of the course of the investigated parameters, the measured values are approximated by empirical polynomials of various degrees. Close correlations between the investigated parameters are identified.

The part of the preparation of experimental verification of shear connectors is also numerical analysis of the examined problem. The main subject of this research is the FEM analysis of a chosen experiment, the push-out test. For FEM analysis, we have opted for Abaqus/CAE software. This piece of work will focus on the modeling of the push-out test via the software stated above.

The MR RC frame structures present a special engineering interest regarding the practical mode of ductile seismic response, through plastic hinges formation in specially designed RC beams end areas and inferior zones of the RC columns from the ground floor. Thus, it was proposed to verify the capacity design concept for this structural system type through seismic response observation of the optimal MR RC frame model. Until this objective is achieved, it was proposed to perform a complex analytical study, which has as finality the current research paper. Thus, in the previous analytical studies the influence of the concrete strength class, the influence of the longitudinal steel reinforcement ratio in RC columns and influence of the RC beams cross sections on the local and global seismic response for a group of RC frame models were analysed. In these conditions, the present paper contains the results obtained in previous research papers and concludes the current analytical study through the observation of the effectiveness of the inferior longitudinal steel reinforcement ratio in the RC beams on the cracking mode, in potentially plastic areas. Finally, it was specified that the K_7 RC frame model represents the optimal structural system for the experimental test.

Wastewater can be an important indicator of surface water contamination by pathogens, of which SARS-CoV-2 is one, so monitoring of wastewater at treatment plants is important. The virus has been shown to be present in the faeces of infected people, which can be detected much earlier than with medical tests. This will allow prediction of trends in coronavirus outbreaks in advance and may complement current measures to determine prevalence. In Slovenia, pilot monitoring was established in seven WWTPs in October 2020. This paper presents the results and analysis of the Maribor WWTP, where one to three 100 ml samples are collected weekly to detect the presence of SARS-CoV-2. A correlation can be observed between the evolution of the virus in the wastewater and the number of active cases detected by the National Institute of Public Health in the region covered by the WWTP. The presence of the virus in the wastewater is detected about two weeks before the increase in active cases. Some shortcomings and further issues of the wastewater monitoring are analysed.

Dynamic complex heat and water transport in building constructions can be calculated using modern simulation software such as Wufi, Delphin, Math, Comsol Multiphysics and other. This software is suitable for the evaluation of the thermal and hygric processes in constructions of historical buildings. Because it includes many important factors such as dynamic boundary conditions, solar radiation, driven rain, ground water, diffusion and others. The heat and water transport parameters of historical materials are needed for simulation of coupled heat and water transport in building materials. The Kežmarok sandstone was chosen for analysis. One of the important material parameters for evaluation of complex heat and water transport in building constructions are water vapor transmission parameters. Vapor transport can be described as water vapor diffusion resistance factor, water vapor diffusion coefficient and diffusion equivalent air layer thickness. The dry cup and wet cup method were used to determine the water vapor transmission parameters of Kežmarok sandstone.

This paper aims to evaluate the effect of replacement of aggregate by recycled one on fracture response of selected composites. These are hemp fibre reinforced cement-based composites. Four different mixtures were prepared: in reference one, the only natural aggregate was used whereas in the other three mixtures, the natural aggregate was replaced by recycled one in the amount of 10, 25 and 50 %, respectively. All mixtures contained hemp fibres with a length of 10 mm in the dosage of 1 % by volume. In order to determine the selected mechanical fracture characteristics of the investigated composites, three-point bending fracture tests were carried out on prismatic specimens with nominal dimensions 40 × 40 × 160 mm³ provided with an initial notch. During the whole course of the testing, the loading process was governed by a constant displacement increment of 0.02 mm/min. The vertical displacement (midspan deflection) was measured using the inductive sensor mounted on a special measurement frame placed on the specimens. The fracture tests were terminated when the midspan deflection reached 0.5 mm. The mechanical fracture parameters were obtained through a direct evaluation of the fracture test data via the effective crack model and the work-of-fracture method. The paper shows that composites with a higher dosage of recycled aggregate (25 and 50 wt%) achieve similar values of mechanical fracture properties, so this replacement can be recommended.

The urgent need to improve the quality in the refurbishment of historical buildings has led to the adoption of many innovative technologies. 3D laser scanning is a non-destructive technique used in the study of architectural heritage. It consists of producing millions of accurate 3D points with a very high point density in a short time. To get the complete 3D model, multiple shots must be taken from different directions that provide data from all sides of the building. These scans are integrated into a common reference system so that through a process of aligning the information obtained in all the stations, a complete model is achieved in a single file. This model faithfully reproduces the current volume of the temple, including its deformations and collapses, and provides very precise information from which to make its geometric survey. The refurbishment project of the Jesuitas Church in Valencia (Spain) has been realized thanks to the help of 3D laser scanning carried out three times during the years 2018, 2019 and 2020. The results obtained have not only served to make a very precise graphic survey but have also been applied in the necessary structural calculation.

Buildings are responsible for significant amount of energy consumption. The new constructions already obliged to use decreased amount of energy, but the older buildings are ineffective compared to them. The new building energetic prescriptions in force since 2021 in Hungary require considerable share of renewable energy produced on-site. In case of a densely built urban fabric, the above renewable ratio can mostly be reached by using solar technologies. The author surveys the solar characteristics of a Budapest downtown area. Considerable ratio of the stock is residential, traditional apartment house type built around the turn of the 19th-20th century. The retrofit solutions and renewable power generation are restricted by the dense fabric and the heritage protection rules as well. In present paper the estimation of solar energy potential of the above characteristic building type is introduced. The European Union conform Hungarian calculations used system is used to define the values. The methodology contains 3D modelling and irradiation software simulation. As result, the connection between the footprint and irradiation data of the characteristic heritage buildings are introduced, as well as the solar power generation potential of the building type in question. Also, the heritage protection compatibility of the solar systems are studied.

A new accelerated corrosion test authorized as ISO16539 Method B in 2013 has shown a good correlation with corrosion behavior in an actual corrosive atmospheric environment. This study aims to extend the application of this method to steel bridge members. The corrosion acceleration tests by the ISO 16539 Method B to weathering steel without anti-corrosive coating and paint-coated steel were conducted through 6 months of the test periods. A series of fundamental studies were conducted to clarify the characteristics of this test in the durability evaluation of the steel used for bridge structural members by comparing the results of the atmospheric exposure test. The accelerated test of 168 days produced the thickness reduction by 10 to 14 times larger than the exposure test of 365 days to the weathering steel. The blister area of the paint-coating as a measure of the paint degradation by the accelerated test was 11 to 14 times larger than the exposure test of 365 days to paint-coated steel. These results showed the effectiveness of the accelerated test by ISO16539 Method B to evaluate the degradation characteristics of the weathering steel and the paint-coated steel.

A basic investigation was carried out in this study to propose a new structure for steel bridge girders by using a combined section composed of steels with different strengths. SM400 as an ordinal strength level steel was selected as the base material for the I-section girder model. It was assumed that the lower flange of the I-section was replaced with an inverted T-shaped member by welding. This member was provided by the different steel with SM400A. The dimension of the inverted T-shaped member was selected to decrease the cross-sectional area to the original section. Furthermore, the moment of inertia and the yielding moment were aimed to increase from those of the original section. With satisfying these conditions, the possibility of cost-saving by using high-strength steel such as SBHS500 was examined. A series of investigations showed the optimum dimensions simultaneously satisfying these mechanical and economic conditions despite being limited.

Creating continuous workflow and reducing variability of construction processes is one of the essential principles of Takt Time system. The Takt Time Planning is a powerful lean tool that creates a continuous flow of people, materials, and resources, therefore it is recognized as a technology with great potential for process innovation in construction. A takt is a demand-driven pace or rhythm of work, which ensures that professionals work at the same speed to free up workspace within standard time frames, leading to a more optimized production process. The main purpose of this article is to explore the practical application and influence of Takt Time Planning on the productivity and efficiency of construction projects by providing an overview of selected case studies. Results show that Tact Time helps to establish a continuous flow and, as a result, reduce waste, reduce the duration and number of inventory buffers, and therefore reduce costs of construction projects.

This study presents the new look on the dormitory's territory, which is located in Jedlikova 5, Kosice, Slovakia. Landscaping design has a significant impact on people, and touches both aesthetic and physical needs, environmental integrity of the area and has an impact on nature habitants. Good landscaping helps to provide a conducive living environment for students by creating needful places for recreation, physical education and studying, as well as producing the natural and healthy ambience to the surrounding by using green roofs, creating a pond for collection of rainwater and planting a lot of greenery. The study framework covers aspects, which are related to the ecological state of the territory, existing environmental problems, natural features and needs of the residents of the dormitory. The aim of the study is to create such a sustainable space, where both students and nature will be in harmony.

The transfer of new materials and technologies that are necessary for the development of new practices will lead to the development of innovation. These options are considered as (1) innovation, which means a significant improvement in the currently required parameters, mostly in parallel with the price increase, (2) innovation will meet the current parameters, but at a lower product / technology price, (3) innovation will achieve compliance with the applicable parameters, but at a higher price of the product / technology. In most cases, this is the second option, i. e. help the customer to enter the market at a lower price while maintaining the required product quality. This case also concerns the application of mixtures of the polymer-modified asphalt mixture type. The main goal of this work was the production and real laying on the verification section of the polymer-modified asphalt mixture. Based on the results obtained from this work, we can conclude that the values of the observed properties prescribed for a given class of asphalt mixtures in the catalogue sheets of asphalt mixtures were achieved without serious problems. Due to the trouble-free production of such mixtures in the plant, spreading and compaction of mixtures, we can express a clear conclusion that such mixtures are an ideal alternative to conventionally used polymer-modified-bitumen mixtures.

The presented work aimed at analysis of elements in the soil and cementitious materials from the selected locations to study the presence of various microorganisms on the surface of buildings. The methodology of the sampling was focused on the interface of the construction containing cement and the soil around the construction in foundation. The chemical analysis by performing X-ray fluorescence analysis confirmed leaching of the element cations of the clinkers. During the carrying out the investigation of the soil, the results additionally showed exceeded limited values of some of the metals elements in the soil which is considered as an environment burden. Moreover, in this research some of the cultivated microorganisms swabbed from the surfaces of the buildings from 14 selected locations are mentioned. These outputs gradually generate the image of the environmental conditions for cementitious materials of selected location in Košice.

A model of continuum is often used in statics and dynamics modeling with material and spatial description. In this paper, we describe body deformation using an innovative approach employing embedding. The mapping ϕ maps a domain from the space Rⁿ to the image of space R^m, where the dimensions of the spaces m and n are necessarily different, usually n < m. Due to the different dimensions m and n, the determinant of the mapping is not defined, nor is the mapping reversible. This complicates the calculation of the fundamental kinematic quantities, the determinant J of the displacement gradient F, the transposed inverse of F, which occur in the Nanson's equation for deformed surface. In this paper, we derive terms for these quantities. The usage of the Moore-Penrose generalized inverse is essential here. This approach is a generalization of the established approach and thus opens up new possibilities in describing deformation. Displacements often appear as one of the basic unknowns, especially when using the finite element method. In the teaching of nonlinear mechanics, we found that the displacements are not adequately defined. In the paper, we therefore attempt to rectify this shortcoming.

Waterways are usually designed as multipurpose structures and perform a number of functions in addition to transport. A very common use is the generation of electricity in hydropower plants, water withdrawal for users and flood protection. On canalized rivers, increased attention must be paid to the design of the layout of the individual structures within the barrage. This paper deals with the optimization of barrage layout with respect to the interaction of navigation and hydropower use of the waterway. The navigation conditions below a power plant can be significantly affected by peak operation or by sudden load rejection. These phenomena can generate a negative surge wave with very adverse effects on navigation. In addition, special attention should be paid to the current conditions in the lower lock approach area and the guard wall that separates the lock approach from the weir and the power plant should be optimised. Appropriate design of operational and structural measures can significantly increase the traffic capacity of a waterway. The research was conducted as part of project no. DG18P02OVV004 within a support programme for applied research and experimental development of national and cultural identity, funded by the Ministry of Culture of the Czech Republic.

The basic parameter for the calculation of the lock filling time is the determination of the forces on the vessels during the filling of the navigation lock. The time required to fill the lock determines the method of filling the lock. The forces on vessels during filling (emptying) directly determine the capacity of the waterway. In the first phase of the lock design, the forces on the vessels during locking are calculated analytically. Most approaches to calculate the forces on vessels are concerned only with finding the maximum value of the forces on vessels. This research deals with the analytical determination of the maximum forces on vessels during the lock filling period. Data from the physical model and the 1D model are used to calculate the maximum forces on the vessels. This simple method can be used to design a new lock. This simple method can be used to design a new lock and to increase the capacity of existing historic locks on the Elbe-Vltava Waterway (Czech Republic) without any structural modifications.

Sustainability of building structures is of particular importance. In recent decades, the use of composite materials to reinforce reinforced concrete structures has proven to be one of the most promising technologies in the field of structural materials engineering. Composite materials have interesting mechanical properties, light weight and have the ability to make complex shapes. Structural efficiency and the efficiency of strengthening technology is one of the most significant advantages for expanding their industrial application. This experimental study scientifically confirms the effect of strengthening with composite materials on the mechanical properties of reinforced concrete beams. The purpose of this reinforcement technique is to improve the load-bearing capacity of the structure and to increase its rigidity and its service life. The aim is to study the mechanical behavior with different configurations to strengthening the structure. The experimental part includes preparation, fabrication and testing of four reinforced concrete beams with the same geometry (270x30x13cm). One non-reinforced beam, which serves as a reference and 3 strengthened reinforced concrete beams with different types of reinforcement configurations. The results show a significant increase in the ultimate load by more than 203% compared to a non-reinforced beam and a one-third reduction in the sagging of reinforced beams.

Materials that exhibit neither purely elastic nor purely viscous behavior, are dealt by viscoelasticity theory. Therein, each material is represented by a viscoelastic model. In this paper a viscoelastic exploration is dealt, focused to the quantification of energy acting during the load – response processes of viscoelastic material. In line with thermodynamic principles, nonnegativity of dissipated energy is supposed within the process, whereby the only reason of energy dissipation is the dashpot, i.e. the viscous member of viscoelastic matter present in the model. The assumption of potential energy storing by and only by the elastic member is taken into account at the same time. Each time we refer a model, the material matching with the model is meant. This work is a continuation, the enhancement of previous research of authors where particular investigations in this field were focused.

Many studies and research point to a growing trend in industrial digitization. New materials, technologies and advanced automation tools are increasingly being promoted in the construction industry. With the increasing degree of digitization, various ways and methods of planning, management and control across different construction processes are also increasing. BIM is a unified information system that enables the sharing of documentation, supports communication, streamlines individual processes, helps eliminate errors and increases quality. Based on this fact, the paper analyses the current state of use of Building Information Modelling in planning and managing the life cycle of buildings in Slovakia and the Czech Republic. The current state of knowledge and use of BIM, defining the advantages and possible barriers to its use, examining the scope and potential of BIM implementation within the building life cycle and defining tools and applications used in time and financial planning of construction production were analysed. The paper also briefly examines how the implementation of BIM can affect selected key tasks of the preparation and valuation professions.

The presented paper deals with the assessment of selected indoor environmental quality (IEQ) factors, specifically the parameters of thermal comfort and indoor air quality (IAQ), in two buildings of a modern office complex. Both buildings are LEED certified. The monitoring of selected IEQ risk factors took place in selected office spaces (cell and open-space offices) representative of all occupied areas under operating conditions. The results of real measurements of IAQ parameters indicate that the monitored office spaces in both buildings did not exceed the required limits set by the LEED certification system. The measured parameters of thermal comfort were within the permissible legislative limits and the results of Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) indices show that a suitable level of thermal comfort can be expected in the given buildings during their occupancy. Based on the results of real measurements, it can be stated that both office buildings actually meet the LEED criteria for IAQ and guarantee a healthy and comfortable working environment for their occupants.

Moving loads represent the dominant component of the load on traffic structures such as bridges and roads. The response of these structures to moving loads can be modeled numerically using a FEM system such as ADYNA or ANSYS. The process requires the creation of a suitable vehicle and bridge computational models. For the purposes of this paper, a spatial computational model of a Tatra T815 heavy truck was created. The modeled bridge is a two span structure with a slab deck. A smooth surface of the bridge is assumed. At the beginning of the solution, the bridge is at rest and the vehicle enters the bridge already vibrated. The dynamic deflections of the bridge and the vehicle over time are monitored. It is possible to display bending moments in the transverse and longitudinal direction and torques at any time. It is also possible to obtain the values of the contact forces between the vehicle wheel and the bridge at any time. The vehicle can move along the bridge at any speed.

This paper deals with a subject of a natural vibration. Modal analysis was performed on a simple membrane structure. Examined model is prepared in FEM software Dlubal. The membrane structure has geometry of a hyperbolic paraboloid or so called hypar. This membrane is basically a technical textile with no bending stiffness so therefore to carry different types of external loads it needs to be pre-stressed. This stress is provided by the edge ropes located in the sleeves around the circumference of the membrane. Stated construction is anchored by 2 anchor rods and 2 actuators to the steel frame which is supported with hinged sliding supports. Natural analysis with an add-on module RF DYNAM Pro was performed. The results of the natural frequencies and mode shapes are obtained which represents first phase of a complex dynamic analysis.

Poorer quality indicators than natural aggregates generally characterize recycled aggregates. This is due to the composition of the primary raw material (mostly demolition waste), the method of processing (crushing, sorting) and the typical character of the grains, which, in addition to the original grain of natural aggregate, also contains the original adhered mortar. The resulting grains are heterogeneous, characterized by lower strength, higher porosity, higher absorbency, or the presence of cracks. Improving the quality of these grains is one of the approaches to increase their potential for use in concrete. Several methods of recycled concrete aggregate (RCA) grain strengthening are being studied worldwide, the effect of which on the final quality of recycled aggregates and new concrete is different. The article describes and compares the methods in terms of their impact on selected properties of both. The comparative analysis is based on the collection of results presented in research publications. Based on the evaluation of the results, polymer emulsion treatment can be identified as the most effective way to improve RCA water absorption. Sodium silicate treatment came out the best to improve the compressive strength of concrete mixed with treated RCA.

Safety training in the construction industry widely adopted virtual reality (VR) technologies to train and educate employees and workers to enhance the safety performance of projects. In this study, a review of VR-based safety training research in construction was carried out to understand the body of literature. Using keywords such as "construction industry" OR "safety training" OR "safety learning," etc., a total of 52 journal articles published between 2000 and 2021 were collected from the Scopus database after advanced filtering. A two-stage analysis of VR-based safety training methods and application areas was carried out were followed by a review. The results indicate that the immersive safety training method was widely used followed by desktop-based, game-based, and BIM-based training methods. VR-based safety training methods are largely applied to hazard recognition (HR), safe operations (SO), and safety awareness (SA). The study findings could assist both academicians and construction practitioners in choosing the best optimal VR-based safety training methods to improve training performance.

River and reservoir bottom sediments are characterized by their physical and chemical properties, which affect the quality of water and deposited sediments in reservoirs. The grain composition of sediments is their fundamental property that determines the detachment, transport and sedimentation of sediments. In addition to understanding the dynamics of transport and distribution of particles in the watershed, the granularity is closely related to the mineral and chemical composition of the sediment and plays an important role in terms of its ability to bind contaminants. Other important property of sediment includes the specific surface area, which determines the nature of sediment surface reactions and influences ecosystem level, biological processes.

This study investigates sediment properties, including physical properties such as grain-size distribution, specific surface area, organic matter and chemical composition, and their reflections on nitrogen and phosphorus adsorption by the sediments deposited in the small water reservoir. The results clearly indicate the dependence of the content of nutrients (nitrogen and phosphorus) in reservoir sediments on their grain size and specific surface area.

Winter stadium in Prešov is situated in an exposed area near the city center, in Slovakia but also in the context of world architecture, it is today an exceptional building with a rope roof structure. The author of the construction is Ing. arch. Čejka, structural engineer doc. Ing. Hajdu, CSc. At the time of design and implementation, it was a very progressive design of the supporting structure, which met the parameters of a world format. The project was modified in 1984 by the completion of outbuildings on the west side of the stadium, mainly due to the need to expand the number of players' locker rooms according to the current needs of athletes. The ice rink was renovated more than 10 years ago, including mantinels and safety glazing.

The application of demand-controlled ventilation is one of the ways, how to reduce energy consumption in residential buildings. The main producer of pollutants in these types of buildings is human being and its activities. The most common measurable air parameters that can be characterized the level of air degradation in rooms are the concentration of carbon dioxide (CO2), air temperature and relative humidity. The aim of our research was to monitor and evaluate these air parameters in real conditions of apartment usage. As part of the research, the experimental measurements were carried out in a selected apartment, where the concentration of carbon dioxide CO2, air temperature and relative humidity were monitored in individual rooms. During evaluating the monitored air parameters, their maximum and minimum values were evaluated. The achieved research results can be applied in computer simulation the operation of a ventilation system in the apartment in order to increase the energy efficiency of the HVAC system while maintaining the required indoor air quality that is necessary for healthy living.

The assessment of deficit and surplus volumes is important for assessing the effects of climate change on water management. Climate change needs to be taken into account in water management. At a time of climate change, there is a frequent occurrence of such periods, but also torrential rains, it is necessary to assess the quantity and quality of surface waters. Building structures must be designed in such a way that, during the period of torrential rains, they retain water from the surface runoff and prevent any damage that could arise from the original; sufficient water and dry season must be ensured during the period. Water shortages can also be caused by increased water consumption. The assessment of the volume of water in the Hornád river basin has shown that it is possible to mitigate climate change.

This paper investigates melanopic equivalent daylight vertical and horizontal illuminances within an indoor space as a metric for the nonvisual effects of its lighting. The article is based on the findings of photobiological research and the recommendations of several institutions for the threshold values of melanopic illuminance at the eyes of users of indoor spaces, which is sufficient for the proper functioning of the circadian system. This study uses a computer workplace as an environment to investigate experimentally the applicability of melanopic daylight metrics for the practical evaluation of the circadian potential of the indoor daylight environment. The article points out a number of problems associated with the practical evaluation of vertical melanopic daylight illuminance in a specific space. The paper also outlines practical guidelines for designing facades and color treatment of building surfaces in terms of their circadian potential.

The paper describes our vision of a green conversion of selected administrative building in Košice, which is supported by the research project APVV-18-0360 ACHIEve Active Hybrid Infrastructure for a sponge city. The greenIZOLA vision represents a set of complex measures, the result of which is a logically, economically, and environmentally justified design of a green building. Within separate stages, the individual parts of the complex and the building are gradually transformed into structures with a potential for retaining rainwater. At the same time, the proposed architectural structures introduce a potential for the creation of experimental structures designed for multidisciplinary research of synergistic links between the building, the environment and vegetation units. The transformation process uses a multidisciplinary approach (BIM, data analysis, life cycle analysis, water retention modelling in the environment, analysis of vegetation units, energy and multiphysical simulations). By applying these approaches, it is possible to monitor the proposed structures, analyse their effects, predict their behaviour, and then optimise the system.

The article deals with Digital twin (DT) technology, as one of the latest technologies, which, unlike construction, is already widely used in other industries. The theoretical knowledge basis of this technology in construction industry lies in understanding the characteristics of the digital twin and in using knowledge about it from other areas of application. Based on acquired theoretical knowledge and an example from construction practice, the aim of the article is to demonstrate the development process of a digital twin and to indicate the benefits of using Asset Information Model (AIM) as an essential source of information for development of DT during the phases of the life cycle of buildings. The case study analyses the process of development of a digital twin of the heating system in family house, from the initial design of a heating project, through use of 3D scanning to create a virtual model and the integration of various tools of Internet of Things technology to the creation of its virtual model. Reflexion on the benefits of AIM in various phases of the life cycle of buildings, induced from the study of theoretical knowledge and based on the case study, is an essential part of the article.

Construction industry has a huge innovation potential focused on the development of new building elements or process procedures. Progressive construction processes are often referred to as modern and cover technologies and systems of various material bases. The drivers and barriers associated with modern methods of construction are generally perceived as a perspective of ensuring sustainable construction, which also reflects their potential application in various construction segments. The aim of the paper is to map companies in the Slovak construction market, which focus their activities on modern methods of construction and then identify the material basis of modern methods of construction. The paper is also focused on determining the application measure of individual types of modern methods of construction in specific construction segments. The research was carried out through own survey and identification of construction companies that declare their activities in the field of production of structural elements, construction of buildings within modern methods of construction.

The aim of this work was to investigate the concentration of stress due to circular cut out in sheets under tensile loads. Geometrical changes and loading create stress concentration. Under this condition, stress has increased in the regions of geometrical changes and if its value exceeds yield stress, the material fails in these regions. In this work, the distribution of stress in sheets with circular cut out was numerically investigated to study stress concentration at the edge of hole and the obtained results were compared with analytical solutions. In addition, relationships among stress concentration factors and relative dimensions of hole were determined using the equations acquired from elasticity theory. It is worth mentioning that the obtained results proved the validity of numerical analysis of all parameters by ANSYS.

The purpose of mathematical modelling of sewer networks is mainly to assess the hydraulic capacity and monitor its behaviour under different conditions to predict the future state. Sewerage network models are also part of the design process. Their advantage is the possibility of simulating the future state of the network and the precipitation and runoff process in the context of climate change. With the help of simulations, it is possible to anticipate future conditions in urban catchments and thus effectively design new networks. The aim of this paper is to summarize mathematical simulation models that are used to model sewer networks.

The paper examines possible solutions for the use of internal insulation in listed buildings. Massive thick walls of historic buildings represent large heat losses and the use of thermal insulation materials from the inside is a possible solution to increase the energy efficiency of historic buildings. However, the use of thermal insulation from the interior is accompanied by a number of risks associated with condensation, mould growth and damage to the perimeter structure. It is necessary to perform dynamic simulations to verify the thermal-humidity behaviour of the structure. The article describes materials suitable for the purpose of internal insulation, their advantages and disadvantages and a description of dynamic simulations by which their effects on the thermal-humidity behaviour of the perimeter wall of a historic building are assessed.

The problem of damping mechanical vibrations has been described in the paper. The subject of the research is a dynamic damper consisting of two steel plates and cuboid rubber blocks to dampen vibrations. The upper plate is subjected to forcing, causing the disturbance to propagate. This disturbance will propagate through the top plate and will pass through the damping material to the bottom plate. The damping elements have been modelled from Mooney-Rivlin material. The aim of the work is to investigate the propagation of vibrations and damping of vibrations and to assess the effects resulting from the selection of material constants with the assumed geometry of the tested system. The results included in the work have been obtained based on a comparative analysis, taking into account the linear material and the nonlinear material. Numerical tests have been carried out with the use of ANSYS software.

The subject of the paper are tubular telecommunication towers, commonly used by mobile telephony operators to build relay stations placed at relatively short distances from each other. The advantage of this type of facilities is their simple structure and small surface area they occupy. It has been observed that during operation, as a result of solar radiation, the towers experience excessive deflection, resulting in disturbances in the operation of transmitting and receiving systems mounted on the towers. The issue of a reliable and relatively precise assessment of the phenomenon of uneven heating of the body surface due to sunlight is not a trivial issue. From a practical view-point, the greatest difficulty is to estimate the temperature to which the surface of a structure exposed to sunlight heats up. Even the attempts at numerical modeling of the phenomenon do not accurately reflect its essence. The paper presents a proposal of a simplified analytical computational model that allows for a practical and uncomplicated estimation of the thermal loads to which such structures are subjected as a result of insolation. The considerations were supplemented with examples from engineering practice, showing the differences in deflection of structures protected by zinc and paint coatings.

Numerous factors may disrupt pavement construction including human errors and unforeseen changes in the environmental conditions. These incidents can shorten pavement life span. New technologies recently came to the aid of contractors and road agencies to detect and possibly mitigate undesirable impacts of unpredictable incidents during the asphalt paving process as well as monitoring pavement performance during pavements service life. In this study, several technologies including layer thickness assessment (using both MIT-scan device coupled with metal plates and conventional topographical technique), infrared thermal camera, intelligent roller compactors, and density gauge devices were utilized to develop a coherent construction system and improve the durability of asphalt pavements in Antwerp, Belgium. The data collected in situ were compared with the characterized cores in the laboratory. It was clear that several factors can influence the outcome of the employed devices. For instance, surface temperatures obtained from an infrared camera fluctuated when the camera tilted from the perpendicular axis. Such discrepancies may be associated with the changes in the distance and environmental condition that affect the refraction of the infrared spectra. It was also found that an elaborated data collection format is essential to clearly understand the correlations between the results of the employed technologies.

A successful construction project respect the construction time and the estimated costs. Such a smooth construction process ensure effective scheduling. A good time construction plan can be a daunting task for a construction contractor. The article deals with time scheduling of line construction in TILOS software. The result is an analysis of scheduling in this software. The advantages and disadvantages of working of modelling a time-distance graph are described. For better control, it is very advantageous to have a well-processed schedule, which will be to the building model by various logical links connected. Thanks to this compound, it is possible to model the building of construction in the shortest possible time and as smoothly as possible. In conclusion, it is stated, that a well-crafted time construction plan can point to possible construction collisions. An updated time-distance graph processed in a software environment can reveal construction risks and the needed rescheduling in a timely manner. Therefore, it is possible to meet the scheduled construction time and estimated costs.

The purpose of the research work is to analyse environmental impacts of building materials applied to the construction of family houses in the boundaries Cradle to Gate with Options. Within Life cycle analysis (LCA), environmental impacts such as global warming potential (GWP), ozone depletion (OP), acidification potential (AP), eutrophication potential (EP), photochemical ozone creation potential (POCP), non-hazardous waste disposal (NHWD) and biogenic carbon storage (BGS) are determined by using One Click LCA tool. This approach is selected to bring information about current state of construction trend used in Slovakia, to set a starting point for further critical reviews of different strategies as well as to inform about the impact significance of current selection of building materials. Results show that the biggest contribution to GWP are triple glazed exterior wooden doors and windows with aluminium elements, thermal insulation and reinforced concrete.

As a result of changes in social, economic, and political relations, undesirable phenomena are created that have an adverse effect on the urban environment. Surface runoff represents one of several risks to environmental policy, causing the major problem in urban agglomerations. In an urbanized area, it causes an increased runoff volume and the flood peak. Also, it affects increasing the contamination of urban rainwater. The significant problem of surface runoff formation in urban river basins is the accumulation of pollutants on the surface of paved areas during the rainless period. In the case of the formation of surface runoff, these substances come into movement. It is assumed that the most polluted rainwater is in the initial phase of runoff formation. However, not all authors agree with the statement. In some literature, this phenomenon is termed the first flush. Given the above facts, the study focuses on surface runoff characteristics in terms of its quality and quantity in the initial phase of surface runoff formatting. The study aims to summarize and compare the results of several studies to evaluate the first rainwater flush in an urbanized area.

The aim of the presented paper is to show possible approaches to the design and verification of the connection of elements to sandwich panels. Rivets or rivet nuts were used. Eurocodes STN EN 1991-1 and 1993-1-8 were used for numerical design. To verify the accuracy of numerical outputs, the samples were verified by a laboratory experiment, and the results were compared.

Document management systems are among the information systems that have several benefits. The main benefits include a reduction of time and of transmitting documents. These systems also allow better access to documents for all participants in construction projects. The use of Document Management Systems in the world is growing in every industry. There has been a dramatic increase in the last few years. However, some construction companies are conservative and are adopting new trends and innovations more slowly. This research addresses this issue of the use of information systems in Slovakia. The research involved investors, contractors, sub-contractors, designers operating in Slovakia. The research sample consisted of 55 respondents, including large construction companies.

The 4D BIM model links the construction schedule and the 3D construction model. The 4D model makes possible to visualize how the construction and its structures in the construction site would look like at any point in time by simulation the construction process. The article provides basic information about BIM technology and 4D modeling. Various levels of tools for creating 4D models are presented in the core of the article. The analysis of selected software from the point of view of their conformity with requirements for creation and for usage of 4D models in construction practice is processed.

The current trend based on the current needs of construction industry points to the increasing application of digital technologies in construction projects. Nowadays, digital technologies are becoming an essential part of construction in the phase of preparation and implementation of construction projects. Probably the greatest progress in the use of digital technologies is seen in the development of a virtual object data model of the building. The main advantages of this trend can be presented by the use of BIM technology, thus an information model of building, where other information attributes are assigned to the geometric model itself. The model created in this way has great information potential in the process of planning and preparation of construction, but also during its implementation. The technology of mixed reality (MR) has recently been added to the BIM technology, which significantly contributes to the expansion of workers' knowledge and at the same time has the potential to reveal the shortcomings that have arisen during the construction. The paper offers solutions of the possible use of BIM technology and mixed reality as tools to support the implementation of construction projects. These technologies were applied to the construction project Bastion Office Center in Košice - an administrative building.

The need of green in cities or the increase of its ratio is very requested in this time of global warming. Buildings in combination with traffic cause so called urban heat islands. The high surface temperature on the facade of buildings causes the increase of surrounding air temperature in the towns. This situation creates the discomfort for their citizens. Also we have to consider with higher operating costs for cooling systems in buildings. The solution how to help is the using of green architecture for each new building but also for reconstructed existing buildings. Green roofs and walls are not new and we have different construction solutions. But this article brings different view on the construction solution of green roofs. It should be the solution that can decrease the heat load of building. This proposed solution allows using the area of flat roof for installation of air handling units and their ducts. The design of space on the flat roof overarched by greens creates better conditions for the operations of air handling units during the hot summer days when the fresh air is sucked from the shaded space that is not overheated by solar radiation.

In March 2018, part of the travertine barrier at Milino Lake, in Plitvice Lakes National Park in Croatia, broke off, significantly altering the flow of water over the barrier. Encouraged by this event, the Faculty of Civil Engineering in Rijeka conducted a monitoring and analysis of the erosion dynamics of the travertine barriers on Plitvice Lakes. Within the project, the analyses of the stability of the travertine barriers were carried out. To the author's knowledge, physical and mechanical properties of travertine have been determined for the first time on samples excluded from travertine barriers between cascading lakes. In addition, no one has previously checked the stability of the travertine barrier located between the two lakes. The maximum compressive and tensile stresses calculated on a numerical model of the broken part of the barrier are compared with the compressive and tensile strength determined by laboratory tests on travertine samples taken from the broken barrier. By comparing the calculated stresses and determined travertine strength, it was found that the stability of the analysed part of the broken travertine barrier at Milino Lake was compromised even if only the self-weight of the collapsed part of the barrier is taken into account.

In this paper, the use of recycled rubber in the form of inserts/fillings or overlays on Ackerman ceiling blocks to partially dampen the propagation of mechanical waves from vibrating machines/devices or accidental shocks from the people movement is discussed. The numerical study is carried out with the use of ADINA software based on Finite Element Method (FEM). The energy transferred via the forced wave is observed in the form of stress plots at given time steps. Four different Ackerman blocks are chosen, which differs in height dimension and shape. In the analysis the complexity of each block supporting is simplified and each block is treated as simply supported on its external edges. The dynamic load is applied to the blocks top surface towards the bottom. For each Ackerman block the analysis is performed twice. The first sequence deals with the Ackerman block itself – without rubber filling, and the second one with insert/filling, what gives the possibility to compare the results of transferred energy. On the basis of presented in paper results, one observes that the rubber filling gives a slight to significant reduction of mechanical wave energy transfer, depending on the block configuration.

Structural failure due to corrosion of steel members is a long-term process. A method to precisely simulate the development of corrosion on steel surfaces is of great significance. In this study, 9 specimens of unpainted steel plates, SM400A were used for the experiments. The experiments were conducted under artificial seawater corrosive environments to accelerate the corrosion process. The corrosion depth data of each unpainted steel plate for the spatial statistical analysis was measured by a laser focus measuring system when the accelerated corrosion experiments of 28, 84, and 168 days. Semivariogram was used in this spatial statistical analysis to research the spatial autocorrelation structures of the corrosion surface. By using this and the technique of ordinary kriging, the method to simulate the spatial features of corrosion surface was proposed. The results of the simulation indicated that the corrosion depth and surface topography of corrosion surfaces were highly consistent with the experiments. In addition, a prediction method for time-dependent corrosion surface was proposed by investigating the relationship between the spatial autocorrelation structures and their time-dependence data.

The paper is focused on the analysis of slope stability. The problem of slope stability is processed theoretically and parametrically - parametrical study. Factors that affect slope stability include: geomorphological conditions, geological conditions, soil and rock properties, and external loads (for example, from traffic, nearby structures, possible vibrations). The shear stress parameters of soil are a keys design parameters for assessment of slope stability. The aim of the parametric study is to point out the importance of knowing the shear stress parameters of soils in assessing the slope stability. By comparing obtained result, it was founded, that change the cohesive has a significant effect on the stability factor.

The analysis is based on the results of computer simulation by using DesignBUILDER software. In the analysis is the multi dwelling house assessed. There are standard building constructions used like as the brick wall with polystyrene thermal insulation, Windows with plastic frame and double glazing and the flat roof with thermal insulation from polystyrene without the gravel layer. In this thermal simulation is considered with so called green walls, that are localized at eastern, southern, and western facade of the building. The light steel frame construction with the net from thin steel ropes creates the area for the climbing plants like a ivy. The function of the used green walls with climbing plants is to shade the external walls of the building in order to reduce the impact of solar radiation on the building facade during the hot summer days. We can these green walls in combination with external blinds consider like a effectively solution in order to reduce the energy consumption for cooling system in the building. By the way the used green walls help to reduce the air temperature surrounding the buildings and so they create the better town climate for their citizens.