Abstract The reinforcement of soil is used to improve its strength and stiffness. The standard method of soil reinforcement is an application of geosynthetics. Soil reinforcement by distributed discrete fibres represents an alternative to those techniques. Currently used fibres have a straight shape, uniform cross-section, and smooth surface, which is not optimal in terms of the fibre-soil interaction. In this study, fibres with a variable shape were utilized. The fibres were fabricated using a fused deposition modelling technology. Firstly, a brief theoretical background is presented. Then, the proposed shapes of the fibres and their manufacturing process are described. The mechanical properties of the soil-fibre composite were investigated through consolidated drained triaxial tests. Well-graded coarse sand and poorly-graded fine sand were used. A higher peak shear strength was observed in the case of fibres with a variable shape. The effect of the variable shape of the fibres on the peak shear strength was higher in the case of the coarse sand.
{"title":"The Reinforcement of Sand by Fibres with a Non-Uniform Shape","authors":"Pavel Koudela, J. Chalmovský, L. Míča","doi":"10.2478/sjce-2021-0013","DOIUrl":"https://doi.org/10.2478/sjce-2021-0013","url":null,"abstract":"Abstract The reinforcement of soil is used to improve its strength and stiffness. The standard method of soil reinforcement is an application of geosynthetics. Soil reinforcement by distributed discrete fibres represents an alternative to those techniques. Currently used fibres have a straight shape, uniform cross-section, and smooth surface, which is not optimal in terms of the fibre-soil interaction. In this study, fibres with a variable shape were utilized. The fibres were fabricated using a fused deposition modelling technology. Firstly, a brief theoretical background is presented. Then, the proposed shapes of the fibres and their manufacturing process are described. The mechanical properties of the soil-fibre composite were investigated through consolidated drained triaxial tests. Well-graded coarse sand and poorly-graded fine sand were used. A higher peak shear strength was observed in the case of fibres with a variable shape. The effect of the variable shape of the fibres on the peak shear strength was higher in the case of the coarse sand.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"29 1","pages":"49 - 54"},"PeriodicalIF":0.4,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42188749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The improvement, reconstruction and repair of roads in recent years have increased the content of recycled asphalt in pavements. Using these materials in road construction projects because they reduce the costs, will also be of great help in improving environmental issues. In the present study, dune sand, which can be found in most desert area soil but does not have proper strength and loading capacity for a subgrade, was used. In order to increase the strength parameters of dune sand, various contents of cement and recycled asphalt were examined in California Bearing Ratio (CBR) and compressive strength tests. The results showed that the addition of cement and recycled asphalt can increase compressive strength and bearing capacity and reduce rupture deformations. In a stabilized sample with 27.5% recycled asphalt, increasing the cement from 7.5 to 12.5% increased the compressive strength by 1.045 times, which is the highest amount of change in the samples studied. The maximum CBR and minimum rupture deformations are related to 35% of the recycled asphalt and 12.5% of the cement. The predicted functions of the compressive strength, deformation and CBR depend on two variables of the cement content; the recycled asphalt was then calculated using the response surface method
{"title":"Effect of Modifying Aggregates by Rap and the Simultaneous use of Adhesives for the Stabilization of a Sandy Pavement Subgrade","authors":"M. Khabiri, Bahareh Ebrahimialavijeh","doi":"10.2478/sjce-2021-0008","DOIUrl":"https://doi.org/10.2478/sjce-2021-0008","url":null,"abstract":"Abstract The improvement, reconstruction and repair of roads in recent years have increased the content of recycled asphalt in pavements. Using these materials in road construction projects because they reduce the costs, will also be of great help in improving environmental issues. In the present study, dune sand, which can be found in most desert area soil but does not have proper strength and loading capacity for a subgrade, was used. In order to increase the strength parameters of dune sand, various contents of cement and recycled asphalt were examined in California Bearing Ratio (CBR) and compressive strength tests. The results showed that the addition of cement and recycled asphalt can increase compressive strength and bearing capacity and reduce rupture deformations. In a stabilized sample with 27.5% recycled asphalt, increasing the cement from 7.5 to 12.5% increased the compressive strength by 1.045 times, which is the highest amount of change in the samples studied. The maximum CBR and minimum rupture deformations are related to 35% of the recycled asphalt and 12.5% of the cement. The predicted functions of the compressive strength, deformation and CBR depend on two variables of the cement content; the recycled asphalt was then calculated using the response surface method","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":" ","pages":"1 - 8"},"PeriodicalIF":0.4,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49086989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Skvarka, E. Bednárová, Marián Miščík, Ľubomír Uhorščák
Abstract The importance of water reservoirs in the uneven distribution of discharges over time and space does not need to be explicitly justified. There is a more than 6,000-year history of convincing evidence. In Slovakia, the construction of reservoirs can be dated to two periods. The first period was the 18th century, when the construction of water reservoirs was stimulated by the need for water for the mining industry in the vicinity of the town of Bánska Štiavnica. The second period falls into the second half of the 20th century. The construction of reservoirs was initiated by the post-war period, including the need to increase society’s standard of living, the electrification of the region, the development of industry and agriculture, flood protection, etc. Reservoirs with multi-annual regulations have an essential position in the types of water reservoirs. While small water reservoirs and annual or seasonal regulation can regulate flows in a short period, reservoirs with multi-annual regulation can regulate flows over several years. This benefit is evident, especially during periods of extreme hydrological phenomena and short-term aquatic and long-term dry, so-called low water periods. We have illustrated our knowledge of and experience gained from their impact on the flows downstream of the Veľká Domaša dam. We analyzed two time periods, i.e., before and after the year 2000. The influence of extreme hydrological phenomena on the runoff conditions downstream of the dam is presented by statistical processing of the available flow series
{"title":"The Domaša Reservoir in the Spectrum of Climate Change","authors":"J. Skvarka, E. Bednárová, Marián Miščík, Ľubomír Uhorščák","doi":"10.2478/sjce-2021-0009","DOIUrl":"https://doi.org/10.2478/sjce-2021-0009","url":null,"abstract":"Abstract The importance of water reservoirs in the uneven distribution of discharges over time and space does not need to be explicitly justified. There is a more than 6,000-year history of convincing evidence. In Slovakia, the construction of reservoirs can be dated to two periods. The first period was the 18th century, when the construction of water reservoirs was stimulated by the need for water for the mining industry in the vicinity of the town of Bánska Štiavnica. The second period falls into the second half of the 20th century. The construction of reservoirs was initiated by the post-war period, including the need to increase society’s standard of living, the electrification of the region, the development of industry and agriculture, flood protection, etc. Reservoirs with multi-annual regulations have an essential position in the types of water reservoirs. While small water reservoirs and annual or seasonal regulation can regulate flows in a short period, reservoirs with multi-annual regulation can regulate flows over several years. This benefit is evident, especially during periods of extreme hydrological phenomena and short-term aquatic and long-term dry, so-called low water periods. We have illustrated our knowledge of and experience gained from their impact on the flows downstream of the Veľká Domaša dam. We analyzed two time periods, i.e., before and after the year 2000. The influence of extreme hydrological phenomena on the runoff conditions downstream of the dam is presented by statistical processing of the available flow series","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"29 1","pages":"9 - 15"},"PeriodicalIF":0.4,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45392628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Our calculation of wind effects was based on the specific wind situation of the planned R2 expressway. Given the topography and the prevailing wind directions, it was necessary to analyse the speeds for winds that could cause vehicles with trailers to be pushed off the roadway, as has been observed in recent years. Using a CFD simulation in the ANSYS FLUENT program, we analysed the entire section of the planned R2 expressway in order to evaluate the wind speeds at the level of the centre of gravity of truck trailers. Statistical turbulence models based on a time-averaging method, i.e., the RANS-Reynolds Averaged Navier-Stokes equations, of turbulent flow quantities and the time-averaging procedure of balance equations are suitable for solving the engineering tasks. In numerical simulations, the Realizable k - ε model was used in which the calculation of the turbulent dynamic viscosity in the equation for Boussinesque’s hypothesis was solved using two transport equations. Plotting and comparing the wind speeds for significant wind directions allowed us to design protection in the dangerous areas using protective walls.
{"title":"Aerodynamic Study of the Wind Flow in the Area of the R2 Expressway in Slovakia","authors":"O. Hubová, M. Macák, Alžbeta Grmanová","doi":"10.2478/sjce-2021-0014","DOIUrl":"https://doi.org/10.2478/sjce-2021-0014","url":null,"abstract":"Abstract Our calculation of wind effects was based on the specific wind situation of the planned R2 expressway. Given the topography and the prevailing wind directions, it was necessary to analyse the speeds for winds that could cause vehicles with trailers to be pushed off the roadway, as has been observed in recent years. Using a CFD simulation in the ANSYS FLUENT program, we analysed the entire section of the planned R2 expressway in order to evaluate the wind speeds at the level of the centre of gravity of truck trailers. Statistical turbulence models based on a time-averaging method, i.e., the RANS-Reynolds Averaged Navier-Stokes equations, of turbulent flow quantities and the time-averaging procedure of balance equations are suitable for solving the engineering tasks. In numerical simulations, the Realizable k - ε model was used in which the calculation of the turbulent dynamic viscosity in the equation for Boussinesque’s hypothesis was solved using two transport equations. Plotting and comparing the wind speeds for significant wind directions allowed us to design protection in the dangerous areas using protective walls.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"29 1","pages":"55 - 61"},"PeriodicalIF":0.4,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43584650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract An analysis of combined piled raft foundations could be performed by means of a special geotechnical finite element software that utilizes 3D modeling and advanced constitutive models for the soil. However, a foundation is generally included in the structural models in a structural design program. The least advanced part of finite element software that has been developed for structural FEM modeling are the tools used for modeling behaviour. A method is required with which the input parameters of the structural design software that are used for modeling the soil structure interaction as well could be determined so that the results calculated by means of a geo-technical software that approximates realistic soil behaviour the best can be reproduced by structural design software as well. The procedure outlined in this paper by means of a cluster analysis provides a tool for a substantial and innovative improvement in subsoil modeling, to which not enough attention is generally paid in the structural FEM software, thereby resulting in a reduced amount of work associated with the task of inputting data.
{"title":"Determination of Subgrade Reaction Coefficients and Spring Stiffnesses for a Combined Pile Raft Foundation (CPRF) by Means of a Cluster Analysis","authors":"Szilárd Kanizsár","doi":"10.2478/sjce-2021-0010","DOIUrl":"https://doi.org/10.2478/sjce-2021-0010","url":null,"abstract":"Abstract An analysis of combined piled raft foundations could be performed by means of a special geotechnical finite element software that utilizes 3D modeling and advanced constitutive models for the soil. However, a foundation is generally included in the structural models in a structural design program. The least advanced part of finite element software that has been developed for structural FEM modeling are the tools used for modeling behaviour. A method is required with which the input parameters of the structural design software that are used for modeling the soil structure interaction as well could be determined so that the results calculated by means of a geo-technical software that approximates realistic soil behaviour the best can be reproduced by structural design software as well. The procedure outlined in this paper by means of a cluster analysis provides a tool for a substantial and innovative improvement in subsoil modeling, to which not enough attention is generally paid in the structural FEM software, thereby resulting in a reduced amount of work associated with the task of inputting data.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"29 1","pages":"16 - 29"},"PeriodicalIF":0.4,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42346821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In this study, a depth-averaged numerical model was employed to investigate the two-dimensional flow features of transitional open-channel flows from a supercritical to a subcritical state. Compared to a shallow-water model, the proposed model incorporates supplementary terms to account for the effects of non-uniform velocity and non-hydrostatic pressure distributions. The model equation was solved numerically by means of the Adams–Bashforth–Moulton scheme. A wide variety of transitional open-channel flow problems such as hydraulic jumps was considered for assessing the suitability of the numerical model. The results of the model for the free-surface profile, pressure distribution, and characteristics of the first wave of an undular jump were compared with the experimental data, and the agreement was found to be satisfactory. Despite the effects of the three-dimensional characteristics of the flow and the bulking of the flow caused by air entrainment, the model performed reasonably well with respect to the simulations of the mean flow characteristics of the curvilinear turbulent flow problems. Furthermore, the results of this investigation confirmed that the model is more suitable for analyzing near-critical turbulent flow problems without cross-channel shock waves.
{"title":"Non-Hydrostatic Transitional Open-Channel Flows from a Supercritical to a Subcritical State","authors":"Y. Zerihun","doi":"10.2478/sjce-2021-0012","DOIUrl":"https://doi.org/10.2478/sjce-2021-0012","url":null,"abstract":"Abstract In this study, a depth-averaged numerical model was employed to investigate the two-dimensional flow features of transitional open-channel flows from a supercritical to a subcritical state. Compared to a shallow-water model, the proposed model incorporates supplementary terms to account for the effects of non-uniform velocity and non-hydrostatic pressure distributions. The model equation was solved numerically by means of the Adams–Bashforth–Moulton scheme. A wide variety of transitional open-channel flow problems such as hydraulic jumps was considered for assessing the suitability of the numerical model. The results of the model for the free-surface profile, pressure distribution, and characteristics of the first wave of an undular jump were compared with the experimental data, and the agreement was found to be satisfactory. Despite the effects of the three-dimensional characteristics of the flow and the bulking of the flow caused by air entrainment, the model performed reasonably well with respect to the simulations of the mean flow characteristics of the curvilinear turbulent flow problems. Furthermore, the results of this investigation confirmed that the model is more suitable for analyzing near-critical turbulent flow problems without cross-channel shock waves.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"29 1","pages":"39 - 48"},"PeriodicalIF":0.4,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45486484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Kalús, Mária Kurčová, Z. Straková, Matej Kubica
Abstract Panels with an integrated active area can be used for interior applications for walls, ceilings and floor heating, and alternatively as a wet or dry type of construction. At present, most panels with an integrated active area are made of gypsum boards with milled channels and embedded pipes. Some manufacturers already supply these panels with thermal insulation (Radwan et al., 2021; Zhang et al., 2020). Certain limitations, mainly regarding the diameter and material of the pipes, apply to the panels with channels milled in the gypsum board and embedded pipes. These limitations are closely related to the high cost of such panels and to the limited heat/cooling output. The disadvantages of these panels are eliminated by the construction of a thermal insulation panel with active thermal protection for application with an active heat transfer control system (indoor thermally active panel (ITAP)) in accordance with European Patent No. EP 2 572 057 B1 (Kalús, 2011).
具有集成活动区域的面板可用于墙壁，天花板和地板供暖的室内应用，也可作为湿式或干式建筑。目前，大多数具有集成活动区的面板都是由石膏板制成的，带有铣槽和嵌入式管道。一些制造商已经为这些面板提供隔热材料(Radwan et al.， 2021;Zhang等人，2020)。在石膏板上铣槽的面板和预埋管有一定的限制，主要是管材的直径和材质。这些限制与这种面板的高成本和有限的热/冷输出密切相关。根据欧洲专利号(ITAP)，这些面板的缺点通过具有主动热保护的隔热面板的构造来消除，该隔热面板适用于主动传热控制系统(室内热活动面板(ITAP))。EP 2 572 057 B1 (Kalús, 2011)。
{"title":"Thermaly Active Interior Panels with an Integrated Active Area","authors":"D. Kalús, Mária Kurčová, Z. Straková, Matej Kubica","doi":"10.2478/sjce-2021-0007","DOIUrl":"https://doi.org/10.2478/sjce-2021-0007","url":null,"abstract":"Abstract Panels with an integrated active area can be used for interior applications for walls, ceilings and floor heating, and alternatively as a wet or dry type of construction. At present, most panels with an integrated active area are made of gypsum boards with milled channels and embedded pipes. Some manufacturers already supply these panels with thermal insulation (Radwan et al., 2021; Zhang et al., 2020). Certain limitations, mainly regarding the diameter and material of the pipes, apply to the panels with channels milled in the gypsum board and embedded pipes. These limitations are closely related to the high cost of such panels and to the limited heat/cooling output. The disadvantages of these panels are eliminated by the construction of a thermal insulation panel with active thermal protection for application with an active heat transfer control system (indoor thermally active panel (ITAP)) in accordance with European Patent No. EP 2 572 057 B1 (Kalús, 2011).","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"29 1","pages":"42 - 47"},"PeriodicalIF":0.4,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44818890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The durability, fatigue resistance, and low-temperature behavior of asphalt layers are greatly affected by the properties of bitumen. Therefore, the composition of bitumen is frequently modified to improve the performance of asphalt mixtures. Sty-rene-butadiene-styrene (SBS) has been the most often used additive recently. Researchers are trying to improve the cohesive and adhesive properties of binders by such polymer-based additives. In this study, 160/220 penetration grade bitumen and Kraton D 1101 SBS were used. The present study contains a new evaluation for determining the cohesive behavior of SBS-modified binders at -1°C, -3°C, and -5°C. The results of this evaluation were compared to conventional and rheological test results. Penetration, softening point, viscosity, dynamic shear rheometer, and bending beam rheometer tests were therefore conducted. Finally, the results of a low-temperature tensile test were found to be consistent with the results of the other tests; hence, they also confirm the cohesive behavior of SBS-modified binders at low temperatures.
摘要沥青的性能对沥青层的耐久性、抗疲劳性能和低温性能有很大的影响。因此，经常对沥青的成分进行改性，以改善沥青混合料的性能。丁烯苯乙烯(SBS)是近年来应用最广泛的添加剂。研究人员正试图通过这种聚合物基添加剂来改善粘合剂的内聚性和粘合性能。本研究采用160/220渗透级沥青和Kraton D 1101 SBS。本研究包含了一种新的评估，用于确定sbs改性粘合剂在-1°C， -3°C和-5°C下的内聚行为。该评价结果与常规和流变试验结果进行了比较。因此进行了渗透、软化点、粘度、动态剪切流变仪和弯曲梁流变仪试验。最后，发现低温拉伸试验的结果与其他试验的结果一致;因此，它们也证实了sbs改性粘合剂在低温下的内聚行为。
{"title":"Evaluation of the Cohesive Properties of SBS-Modified Binders at Low Temperatures","authors":"B. Kök, Yunus Erkuş, M. Yılmaz","doi":"10.2478/sjce-2021-0005","DOIUrl":"https://doi.org/10.2478/sjce-2021-0005","url":null,"abstract":"Abstract The durability, fatigue resistance, and low-temperature behavior of asphalt layers are greatly affected by the properties of bitumen. Therefore, the composition of bitumen is frequently modified to improve the performance of asphalt mixtures. Sty-rene-butadiene-styrene (SBS) has been the most often used additive recently. Researchers are trying to improve the cohesive and adhesive properties of binders by such polymer-based additives. In this study, 160/220 penetration grade bitumen and Kraton D 1101 SBS were used. The present study contains a new evaluation for determining the cohesive behavior of SBS-modified binders at -1°C, -3°C, and -5°C. The results of this evaluation were compared to conventional and rheological test results. Penetration, softening point, viscosity, dynamic shear rheometer, and bending beam rheometer tests were therefore conducted. Finally, the results of a low-temperature tensile test were found to be consistent with the results of the other tests; hence, they also confirm the cohesive behavior of SBS-modified binders at low temperatures.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"29 1","pages":"27 - 34"},"PeriodicalIF":0.4,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45467724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The construction process is characterized by a diverse technological composition and the use of a wide range of construction machinery and mechanization. The amount of machinery increases with the complexity of the construction, which increases the demands concerning the preparation and overall organisation of the construction. The preparation of construction processes carried out by helicopters (aerial work) must respect the effect of randomly changing construction conditions as well as the specific working conditions of helicopters. The complexity of such a system can be modelled using simulation models. In the work presented, we designed and practically tested a simulation model of aerial work in the MATLAB software environment. An essential part of the simulation model is an algorithm designed on the basis of commercial numerical weather prediction models. We consider the outputs of the simulation to be reliable, because they are very close to the actual results achieved in the case of the implementation of construction of this type. The concept of the simulation model enables its wider use not only in the construction sector, but also in other branches of industry.
{"title":"Simulation Modelling of Aerial Works and Its Role in the Preparation of Construction","authors":"A. Bisták, Z. Hulínová, Michal Neštiak","doi":"10.2478/sjce-2021-0004","DOIUrl":"https://doi.org/10.2478/sjce-2021-0004","url":null,"abstract":"Abstract The construction process is characterized by a diverse technological composition and the use of a wide range of construction machinery and mechanization. The amount of machinery increases with the complexity of the construction, which increases the demands concerning the preparation and overall organisation of the construction. The preparation of construction processes carried out by helicopters (aerial work) must respect the effect of randomly changing construction conditions as well as the specific working conditions of helicopters. The complexity of such a system can be modelled using simulation models. In the work presented, we designed and practically tested a simulation model of aerial work in the MATLAB software environment. An essential part of the simulation model is an algorithm designed on the basis of commercial numerical weather prediction models. We consider the outputs of the simulation to be reliable, because they are very close to the actual results achieved in the case of the implementation of construction of this type. The concept of the simulation model enables its wider use not only in the construction sector, but also in other branches of industry.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"29 1","pages":"20 - 26"},"PeriodicalIF":0.4,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43128371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andrea Biskupičová, M. Ledererová, S. Unčík, C. Glorieux, M. Rychtáriková
Abstract This article reports on impedance tube measurements of the sound absorption coefficient α (-) of selected recycled foam plastics, i.e., ethylene-vinyl acetate (EVA), polyvinyl chloride (PVC), polystyrene (PS), and polypropylene (PP), in different mixtures with a binding adhesive. The effect of the thickness of the sample on the sound absorption spectrum as well as the variability in absorption across the different samples of the same composition and thickness are discussed. For the EVA/ PP and PS/PP mixtures, the spectrum is characterized by two peaks that shift as the thickness is changing. These mixtures were also found to be the most absorbent across the whole audible frequency range.
{"title":"Sound Absorption Properties of Materials Based on Recycled Plastic Granule Mixtures","authors":"Andrea Biskupičová, M. Ledererová, S. Unčík, C. Glorieux, M. Rychtáriková","doi":"10.2478/sjce-2021-0003","DOIUrl":"https://doi.org/10.2478/sjce-2021-0003","url":null,"abstract":"Abstract This article reports on impedance tube measurements of the sound absorption coefficient α (-) of selected recycled foam plastics, i.e., ethylene-vinyl acetate (EVA), polyvinyl chloride (PVC), polystyrene (PS), and polypropylene (PP), in different mixtures with a binding adhesive. The effect of the thickness of the sample on the sound absorption spectrum as well as the variability in absorption across the different samples of the same composition and thickness are discussed. For the EVA/ PP and PS/PP mixtures, the spectrum is characterized by two peaks that shift as the thickness is changing. These mixtures were also found to be the most absorbent across the whole audible frequency range.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"29 1","pages":"15 - 19"},"PeriodicalIF":0.4,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43079219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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