bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of mathematical models in design and assessment of sewer network facilities
Authors: Csicsaiová R , Hrudka J , Marko I , Stanko Š 
Published: October 2020

Abstract
The application of mathematical models has been expanding in the field of sanitary and environmental engineering. Mathematical models are used in the design and assessment of sewer networks and their facilities. Sewer network models make it possible to create a model of hydraulic and Physico-chemical processes in wastewater flowing through the sewage network. The number of extreme rainfall events is increasing due to climate change. It causes a collapse in the infrastructure of urbanized areas. It is possible to investigate the flow of wastewater under extreme rainfall and to propose measures to eliminate adverse events using mathematical models. Nowadays, it is possible to use modern calculation procedures, which are used to dimension and assess existing facilities. This paper aims to focus on the application of numerical models in the design and assessment of combined sewer overflow chambers. The combined sewer overflow serves to carry away a part of the rain flows from the network to the nearest suitable receiving water body. Their main task is to reduce the uneven load of wastewater treatment plants by rainwater. The combined sewer overflow chambers distribute the inflow into the flow going to the wastewater treatment plant and the lightened flow going to the receiving water. The aim of this paper is to summarize the knowledge of CFD modelling and to get acquainted with the basic principles. In brief, the normal flow describes its simulation using two basic models. Finally, it focuses on the recapitulation of foreign studies and their use in the assessment and design of relief chambers and regulatory objects of the single sewer networks.
Share of the volume of work types and financial costs according to the stages of construction of reinforced concrete monolithic buildings
Authors: Doubek R 
Published: October 2020

AbstractThe aim of the paper is to evaluate the technological and economic demands on the construction of multi-storey reinforced concrete monolithic buildings for administrative purposes incorporating the stages of construction, technological stages and selected partial construction processes.The entry criteria for objects that are included in monitoring and evaluation are their identical location, used technologies, mechanization, built-in materials and their purpose.The purpose of the paper is to prepare tables for the professional and academic public for a rough idea of the proportional representation of time and financial consumption in the construction of this type of object, for selected stages of construction, technological stages and selected partial construction processes.
Analysis of the efficiency of sewerage with the illegal rainwater inflow
Authors: Hrudka J , Marko I , Šutúš M , Stanko Š 
Published: October 2020

Abstract
In our research, we are focused on analysing the impact of illegal rainwater connections on the sewage network. During the normal operation of the sewage network, rainwater cannot be present. These heavy rains flows are extreme during rain events and the sewerage system is significantly overloaded and functionality it is reduced. Our study is based on the real data of the sewerage network and selected area of interest. In the assessment of illegal connections of rainwater, we use rainfall data according to the relevant ombrographic station.
Old cement-based render as the cause of extremely low carbonation of 100-year bridge concrete
Authors: Húlek L , Bačuvčík M , Gašpárek J 
Published: October 2020

Abstract
In-situ research and laboratory examination provided on concrete core samples from old bridge structures confirmed that a thin layer of ordinary cement-based render coat protects the underlying concrete from carbonation. The average measured value by phenolphthalein test was less than 2 mm after more than 100 years of service life in exposure class XC3 of EN 206. Low carbonation depth is explained by the presence of a thin (2-4 mm) layer of the protective render coat (PRC) situated on the bridge concrete. The place, where the PRC was of good quality was almost impermeable and the carbonation of the concrete underneath was even 0 mm. If the PRC locally spalled, the carbonation depth of the same concrete, at the same structure and environment reached at this place even more than 80 mm. It was observed that low carbonation of concrete significantly depends on the non-permeability of the PRC. A narrow free space filled with the carbonates causes increased non-permeability of the PRC creating thus the built-in limestone-based (anti-carbonation) barrier with the ability to dramatically reduce CO2 penetration into the beneath concrete over time. Values from in-situ and laboratory research are presented in the article with the explanation of these phenomena.
Shear strength of in-plane loaded cross laminated timber beam elements – experimental and theoretical investigation
Authors: Jeleč M , Strukar K , Rajčić V 
Published: October 2020

Abstract
Cross laminated timber (CLT), as a versatile engineered timber product, has in recent years become well-known and of global interests. The orthogonal laminar structure allows for application as beams, walls or panels for both out-of-plane and in-plane loading conditions. The work presented here concerns experimental investigations of in-plane loaded CLT beams, as very relevant from a practical engineering point of view due to reinforcing effect of transversal layers with respect to stress perpendicular to the beam axis. Experimental results are used for comparison and validation of design proposals from the literature, with the main focus on the shear failure mode III in crossing areas between orthogonally bonded longitudinal and transversal lamination. By using the assumed shear strength values from the literature, analytically predicted shear carrying capacities show good agreement with the experimentally obtained. Although further experimental validation is needed, obtained results indicate that suggested design proposals should be considered in ongoing revision work of Eurocode 5.
Evaluation of frost resistance of various blended binders
Authors: Kardosova E 
Published: October 2020

Abstract
The use of blended binders using alternative raw materials is one of the key areas of sustainable development in terms of reducing CO2 in the atmosphere. This approach reduces the proportion of energy-intensive clinker in cement when satisfying technical parameters. The paper presents a proposal of variants of blended binders with the application of fly ash, blast furnace slag and perlite for their use in building mixtures. The durability of the mixtures is assessed on the basis of testing the frost resistance of mortars. Test specimens were produced according to STN EN 196-1. The samples were subjected to 25 freeze-thaw cycles, and both the flexural and compressive strength were then determined, to express a durability factor. Except for slag as a standard component of blended binders, perlite appears to be a perspective material; it meets a limit for durability factor when used as a 30% substitution for cement, as well as when used in ternary composition with slag. Fly ash showed weak frost resistance, even when used with a suitable perlite.
Analysis of mechanical properties of I-beam with web from transparent wood
Authors: Kanócz J , Bajzecerová V , Karl’a V 
Published: October 2020

Abstract
This article contains a brief information about history of transparent wood, its fabrication process and its physical and mechanical properties. The main goal of this article, however, is to find whether transparent wood is a suitable material for load-bearing architectural constructions. This is achieved by using numerical analysis of I-beam with web from transparent wood (and various types of it) and comparing its results with the same sized beam with web from OSB (oriented strand board) and web from glass, which are both successfully used for such applications nowadays. Suggestions on how to use transparent wood as a load-bearing material are also presented in the article.
Alternatives of solar systems and their analysis
Authors: Kosican J 
Published: October 2020

Abstract
This study negotiates with percentage fraction for heating and hot water of various solar systems. Research building of the Technical University of Košice was selected. For this analysis, we used simulation appropriate simulation software, which replicates solar systems and calculates the production of the proper solar system. If we consider DHW solar ratio, the fifth alternative, which includes a combination tank system (heating buffer tank) with an outside heat exchanger and a swimming pool, is the most productive. Nonetheless, in accordance of overall solar fraction, the top choice is alternative 4, which is a mix of DHW tank system with a heat exchanger inside the tank. At the end, the outcome demonstrates that, mix of DHW tank and buffer tank for space heating with a swimming pool, that is alternative 6, seems to be the worst case. Efficient usage of different systems based on renewable energy sources and their applications secures Investigated centre mentioned before.
Compressive strength of concrete specimens with inclusions
Authors: Kovac M , Sabol P , Kusnir S , Kusnirova D , Rovnak M 
Published: October 2020

Abstract
Large diameters and grain aggregates and/or reinforcing bars can have a negative impact on the strength of concrete elements. Tests of concrete specimens with inclusions under uniaxial compression should contribute to a better understanding of the process of failure of concrete elements. The identification of the unstable phase of the cracking and quantification of the effect of diameters, positions, distances, number and material of inclusions, as well as the relative size of inclusions and matrix on compression strength could provide information for an explanation of the causes of the size effect in compressed structural elements. The introduction of the article provides a brief overview of the problem of concrete structures subjected to uniaxial compression. Attention is paid to the failure mechanisms in the process of loading the test specimens from initial crack formation to specimen collapse. The second part is devoted to the investigation of the size effect of varying dimensions of the test specimens with one or three inclusions.
Environmental assessment of existing pavements asphalt layers for production of new asphalt mixtures
Authors: Kovács R , Mandula J 
Published: October 2020

AbstractRoad construction requires a large amount of construction materials. During asphalt pavement construction it is natural aggregate and asphalt binder in particular. Their ratio varies depending on whether they are applied in an asphalt pavement as a wearing, binder or base course. Nowadays, pressure of public opinion on responsible environmental behaviour and effective use of financial resources create an optimal space for assessment of building materials from pavement layers. According to the EAPA (European Asphalt Pavement Association) data from 2017 the wearing courses accounted for 90 % of all pavement layers in European Union. In Slovakia their representation is also dominant. While in Western Europe reassessment of existing asphalt layers by recycling technologies has been used to the maximum, in Slovakia the reassessment was out of interest of construction companies. With the arrival of new machinery, legislation amendment and social pressure on responsible environmental behaviour, the strategy of some construction companies in Slovakia is also changing. The reassessment of existing asphalt layers for production of new asphalt mixtures goes to the forefront of the interest. This article summarizes necessary steps to achieve an increase in the re-use rate of R-material by hot-mix asphalt recycling technology in asphalt mixing plants.
Comparative analysis of magnesium oxide boards properties
Authors: Mokrenko D , Kozlovská M 
Published: October 2020

Abstract
The current sustainability trends pose high demands on building materials and products. Those with potential to be labelled as an environmentally-friendly product or technology are getting preferred. One of the natural resources with such potential is magnesite, whose resources are widely found in Slovakia. The article deals with analysis of the magnesium oxide board properties as the most popular MgO-based building product. The comparative analysis of magnesium oxide boards with other available building boards (plasterboards, oriented strand boards) is included in the article and especially from the point of magnesium oxide boards’ benefits.
The conformity of the tools of selected software programs for 4D building modeling
Authors: Nechyporchuk Y , Bašková R 
Published: October 2020

Abstract
4D modeling is a part of the BIM (Building Information Modeling) platform. It represents the design approach, when the building is designed not only in space (3D) but also in time (3D + time). The aim of the article is to compare Autodesk Navisworks and Synchro Pro in terms of the conformity with the requirements for creating and using 4D building models. The introduction represents the resource search where the advantages and ways of using 4D modeling for construction and the situation of its applying in Slovakia and abroad are summarized. Besides, the 4D model of the building Water World, created in Autodesk Navisworks and Synchro Pro, is introduced there. In the conclusion, there is a comparison of the tools of this software in user’s several points of view.
Experimental investigation on bond-slip behavior of selfconsolidating rubberized concrete
Authors: Strukar K , Jeleč M , Kalman Šipoš T , Grubišić M , Lukić S 
Published: October 2020

Abstract
Reducing the industry’s impact on the environment is the goal of sustainable construction which can be achieved by using renewable and recyclable resources such as scrap tire waste. Great potential of this waste is found in construction mostly as a partial replacement of mineral aggregate in concrete and mortars, asphalt mixtures and geotechnical works. Previous studies on the selfconsolidating rubberized concrete (SCRC) are mostly concerned with mechanical properties of rubberized concrete. However, in order to allow structural application, it is also necessary to investigate bond-slip behavior of SCRC and reinforcement bars. Thus, in this paper pull-out tests are performed on 24 cubic samples with reinforcement confinement. Three different SCRC mixtures are made, first with concrete without rubber particles as reference mixture, second with 10%, and third with 15% rubber particles and 5% silica fume. The other parameter varied is diameter of steel bars (∅12, ∅16, and ∅20 mm). From the results obtained in experimental investigation, key bond parameters and failure modes of SCRC are compared with bond-slip behavior of self-consolidating concrete (SCC).
Numerical nonlinear analysis of a membrane structure subjected to dynamic load
Authors: Stulerova L , Kapolka L , Kmet S 
Published: October 2020

Abstract
The aim of this paper is the numerical analysis of a thin technical textile in shape of hyperbolic paraboloid. It is the membrane structure, which can function only in tension and it is geometrically nonlinear, therefore nonlinear analysis has to be carried out. In this case, the structure was subjected to the dynamic loads effects. Natural vibration was applied as a fundamental dynamic characteristic. All of this results in natural frequencies and mode shapes and deflections. Acquired results describe the dynamic behaviour of nonlinear system. This part of the analysis could represent a first step in the dynamic analysis. To complete the dynamic analysis of the membrane structure, the forced vibrations as nonlinear time history analysis will have to be performed in a future.
The effect of CO2 on the strength characteristics of cement composites based on recycled rubber from waste tires
Authors: Svoboda J , Vaclavik V , Dvorsky T , Charvat J , Macalova K , Papesch R 
Published: October 2020

Abstract
This paper presents the results of a research into the use of a combination of recycled rubber from waste tires as a 100% aggregate replacement in the production of cement composites. The aggregate was replaced with rubber recycled material in two ratios. At a ratio of 50/50 and a ratio of 40/60 fraction 0/1 mm and fraction 1/3 mm. The test specimens were further subjected to CO2 effect in a Lamart laboratory chamber, where CO2 effect was simulated as equivalent to an aging period of 50 years. The presented results show that the effect of CO2 reduces the strength characteristics of the composite compared to the comparative samples.
LCA analysis of Slovak residential building
Authors: Tomková Ž 
Published: October 2020

Abstract
Building industry is main contributor to greenhouse gas (GHG) emissions. According to goals of Paris agreement to achieve temperature rise below 2°C a year and then below 1,5°C a year, we need to find where are our biggest possibilities of improvement. Focus of this paper is on residential buildings built in Slovakia. With population growth also demand for apartments rises. With residential building development comes possible place for improvement. That is why main goal of this assessment is to analyse current state of our residential building fond using eToolLCD software and cradle to grave approach. Selected environmental impact of this analyse are, global warming potential (GWP), ozone depletion (OP), acidification potential (AP), eutrophication potential (EP), photochemical ozone creation potential (POCP), abiotic depletion potential of elements (ADPE), abiotic depletion potential of fossil fuels (ADPF) and also use of primary energy resources (PENERT). Assessed residential buildings are first part of larger investigation in this sector.
Analysing the cumulative energy demand of external bearing walls
Authors: Wolfova M 
Published: October 2020

Abstract
The assessment of environmental properties of buildings is now commonly using a life cycle analysis (LCA). Due to the rapidly evolving construction industry, LCA research is carried out in many areas, from building materials and components to overall building system. Life Cycle Assessment (LCA) is a tool used to compare environmental impacts along the life cycle of products or services. This paper presents an evaluation and comparing of two external bearing walls of different material compositions regarding the materials´ total energy consumption within the cradle to gate boundaries. Impact categories were calculated by the software SimaPro using Cumulative Energy Demand (CED) method and applying the Ecoinvent database. A renewable (biomass, wind, solar, geothermal, water) and non-renewable (fossil, nuclear, biomass) energies were under consideration. The composition with brick as a core wall material achieved worse results in all categories than the wall composition with aerated concrete block.
Conductive natural and waste rubbers composites-loaded with lead powder as environmental flexible gamma radiation shielding material
Authors: El-Khatib Ahmed M , Doma A S , Badawi Mohamed S , Abu-Rayan Asmaa E , Aly N S , Alzahrani Jamila S , Abbas Mahmoud I 
Published: October 2020

Abstract
It is well known that materials with lead (Pb) content are very effective as protective materials against radiation. Natural rubber (NR) has been loaded with 30 phr of N220 black (critical concentration) as a conductive and reinforcing filler. These rubber matrices are loaded with different concentrations of Pb powder (up to 100 phr) as filler. Gamma attenuation study was carried out using 3″ × 3″ NaI (Tl) (scintillation detector) gamma-ray spectrometer for (Cs-137), (Co-60), (Ba-133), and (Eu-152). The effect on the shielding property of Pb/NR composite was studied by varying the content of Pb and photon energy. It was found that the addition of Pb filler remarkably increases the linear attenuation coefficient (μ) of Pb/NR composites, especially for low photon energy. Linear attenuation coefficient experimental measures and theoretical calculations (using the XCOM code) were performed. It was noted that there is a reasonable agreement between measured and calculated results. In this paper, gamma-ray radiation shielding parameters are also studied for composites based on waste rubber. Its experimental results showed that Pb/W/NR composites have better γ shielding ability compared to Pb/NR ones at the Pb contents so, these are promising materials for fabricating protecting clothes against radiation in addition to their low cost and effective aid to get a clean environment.
Corrosion behavior of Cr-bearing steels in CO2-O2-H2O multi-thermal-fluid environment
Authors: Yuan Juntao , Zhu Kaifeng , Jiang Jingjing , Zhang Huihui , Fu Anqing , Li Wensheng , Yin Chengxian , Li Fagen 
Published: October 2020

Abstract
Multi-thermal fluid is used to enhance heavy oil recovery, but it also causes severe corrosion failure of metallic tubing and its mechanism is still open to debate. In the present work, the corrosion behavior of commercial steels with different Cr content (3 wt%, 9 wt%, and 25 wt%) in simulated CO2-O2-H2O multi-thermal fluid environments were studied by immersion corrosion test and microstructural characterization. The results exhibit that the Cr content of steel determines the type of corrosion products. The less protective corrosion scale is mainly composed of FeCO3, (Fe, Cr)3O4, and Fe2O3, which is formed on the surface of 3Cr and 9Cr steels. The protective corrosion scale is mainly Cr2O3, which is formed on the surface of 25Cr steel. Only when the Cr content in steel is sufficient (i.e. 25 wt%) to repair the serious depletion of Cr in the metal near the scale/metal interface in time, can protection of the corrosion scale be sustained, to improve its ability to resist the corrosion of multi-thermal fluids.
Effect of (Sm, Co) co-doping on the structure and electrical conductivity of ZnO nanoparticles
Authors: Almoussawi Mohammed , Abdallah A M , Habanjar Khulud , Awad R 
Published: October 2020

Abstract
(Sm, Co) co-doped ZnO nanoparticles (Zn1−2xSmxCoxO),

0.00
≤
x
≤
0.06
,

have been prepared by the co-precipitation technique. The effect of the dopant ions Sm3+ and Co2+ on the structural, morphological, and electrical conductivity of ZnO has been studied. XRD analysis shows the substitution of Zn2+ ions by the co-doping Sm3+ and Co2+ ions with the formation of secondary phases as Sm2O3 and Co3O4 upon 0.005 co-doping and above. Raman spectra showed the characteristic mode of the wurtzite structure of ZnO nanoparticles with a vibration assigned to the bound of Co with the donor defects at high doping level of (Sm, Co). The spherical morphology of pure ZnO is transformed into nanorods as the concentration of Sm3+ and Co2+ increases. From EDX spectra, it was shown that all samples exhibit an excellent compositional homogeneity that verifies the Sm and Co presence as real dopants in ZnO crystalline structure. FTIR spectra show one discrete peak at 417 cm−1 with another broad peak at 568 cm−1corresponding to Zn–O stretching, which confirms the formation of the wurtzite structure of the samples. Photoluminescence studies reveal the existence of minor defects in the co-doped samples. The study proposes the suitable use of the samples in the high-efficiency UV light-emitting devices due to the intense UV peaks compared with the lower visible peaks. The excitation dependent PL spectra demonstrated a redshift with increasing the excitation wavelength accounting for the distribution of energetic species in the ground state. The DC electrical conductivity is enhanced with (Sm, Co) co-doping of x = 0.1 due to the formation of thermally activated donor levels.