Abstract The article deals with the factors that lead to the beginnings of the solidification and hardening of materials used in 3D home printing technology in construction. At the beginning, the composition of the materials as well as their essential fresh and hardened properties and the performance assumptions of such a mixture are described. Subsequently, the article discusses the main aspects of the rheology and hydration of cement composites and the use of additives such as superplasticizers, viscosity modifiers, and acceleration and retardation additives, which directly affect the onset of the setting of such materials and the strength of the resulting mixtures. Finally, we describe the printing and curing process of the extruded material, which is divided into 4 main phases from the pumping and extrusion of the material through the initial deposition of layers to a sufficient increase in strength in the required time.
{"title":"Effecting the Rheological Properties of Composites for 3D Printing Technology in Construction","authors":"Adam Uhlík, Mário Buch, S. Unčík","doi":"10.2478/sjce-2022-0006","DOIUrl":"https://doi.org/10.2478/sjce-2022-0006","url":null,"abstract":"Abstract The article deals with the factors that lead to the beginnings of the solidification and hardening of materials used in 3D home printing technology in construction. At the beginning, the composition of the materials as well as their essential fresh and hardened properties and the performance assumptions of such a mixture are described. Subsequently, the article discusses the main aspects of the rheology and hydration of cement composites and the use of additives such as superplasticizers, viscosity modifiers, and acceleration and retardation additives, which directly affect the onset of the setting of such materials and the strength of the resulting mixtures. Finally, we describe the printing and curing process of the extruded material, which is divided into 4 main phases from the pumping and extrusion of the material through the initial deposition of layers to a sufficient increase in strength in the required time.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"30 1","pages":"49 - 56"},"PeriodicalIF":0.4,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49371247","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}
Ali Moasami, Bahador Fatehi-Nobarian, Y. Hassanzadeh
Abstract Very large floating structures (VLFSs) have various applications, such as recreational applications, port facilities, etc. A surge in the population, the advantages of building floating structures compared to traditional methods of land extraction from the sea, and the development of construction technologies, have led to engineers paying attention to very large floating structures. Bracing systems are capable of controlling and reducing the horizontal responses of a floating platform, but they have no major impact on its vertical responses. In the present study, the semi-floating platform was numerically designed to be least affected by the three factors of wave force, horizontal torsion, and horizontal displacement. In order to optimize the design, the semi-floating platform was simulated and subjected to the three wave directions with collision angles of 40, 45 and 55 degrees in the environmental conditions of the Caspian Sea and by exerting the wave effect in a Flow-3D model. Examination of the platform’s movements has demonstrated that the arrangement of an eight-way restraint system with a 40-degree restraint angle responds better to the impact of waves and is more economical compared to other designs.
{"title":"Numerical Study on the Effect of Water Waves and Depths on Inclined Braces with Respect to the Stability of VLFS Platforms in the Caspian Sea","authors":"Ali Moasami, Bahador Fatehi-Nobarian, Y. Hassanzadeh","doi":"10.2478/sjce-2022-0005","DOIUrl":"https://doi.org/10.2478/sjce-2022-0005","url":null,"abstract":"Abstract Very large floating structures (VLFSs) have various applications, such as recreational applications, port facilities, etc. A surge in the population, the advantages of building floating structures compared to traditional methods of land extraction from the sea, and the development of construction technologies, have led to engineers paying attention to very large floating structures. Bracing systems are capable of controlling and reducing the horizontal responses of a floating platform, but they have no major impact on its vertical responses. In the present study, the semi-floating platform was numerically designed to be least affected by the three factors of wave force, horizontal torsion, and horizontal displacement. In order to optimize the design, the semi-floating platform was simulated and subjected to the three wave directions with collision angles of 40, 45 and 55 degrees in the environmental conditions of the Caspian Sea and by exerting the wave effect in a Flow-3D model. Examination of the platform’s movements has demonstrated that the arrangement of an eight-way restraint system with a 40-degree restraint angle responds better to the impact of waves and is more economical compared to other designs.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"30 1","pages":"42 - 48"},"PeriodicalIF":0.4,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47382546","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 This paper presents a numerical parametric study of the moment-curvature and curvature ductility of doubly-reinforced beams with different parameters. The effects of the strength of the concrete and the amount of the reinforcement, including the tensile and compression reinforcement on the complete moment-curvature behavior and the curvature ductility factor of the beam sections, have been studied. A new predictive formula for the ductility factor of beam sections that considers the different parameters has been developed. In a continuation of the study, the flexural ductility of beams designed with different parameters according to the ductility factor proposed by different researchers was investigated. Based on the results of the numerical analysis, the proposed predictions for the curvature ductility factor were verified by comparisons with other predictive formulas. The proposed formula offers fairly accurate and consistent predictions for the curvature ductility factor of beam sections. It is shown that the concrete’s compression strength and the amount of reinforcing steel, including the compression reinforcement ratios, have an effect on the curvature ductility factor of beam sections.
{"title":"A New Approach for Determining the Curvature Ductility of Reinforced Concrete Beams","authors":"Saeid Foroughi, S. B. Yuksel","doi":"10.2478/sjce-2022-0002","DOIUrl":"https://doi.org/10.2478/sjce-2022-0002","url":null,"abstract":"Abstract This paper presents a numerical parametric study of the moment-curvature and curvature ductility of doubly-reinforced beams with different parameters. The effects of the strength of the concrete and the amount of the reinforcement, including the tensile and compression reinforcement on the complete moment-curvature behavior and the curvature ductility factor of the beam sections, have been studied. A new predictive formula for the ductility factor of beam sections that considers the different parameters has been developed. In a continuation of the study, the flexural ductility of beams designed with different parameters according to the ductility factor proposed by different researchers was investigated. Based on the results of the numerical analysis, the proposed predictions for the curvature ductility factor were verified by comparisons with other predictive formulas. The proposed formula offers fairly accurate and consistent predictions for the curvature ductility factor of beam sections. It is shown that the concrete’s compression strength and the amount of reinforcing steel, including the compression reinforcement ratios, have an effect on the curvature ductility factor of beam sections.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"30 1","pages":"8 - 20"},"PeriodicalIF":0.4,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43452407","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}
Oluwatosin Olofintoye, Am Ayanshola, A. W. Salami, Akim Idrissiou, J. O. Iji, O. Adeleke
Abstract This study investigates the applicability of a Soil and Water Assessment Tool (SWAT) model in predictions of the water yields and water balance of the Upper Oueme catchment in the northern part of the Republic of Benin. Meteorological and hydrological data for a period of 20 years were collected from the Meteorological Agency of Benin and the National Directorate of Water respectively. Spatial data such as a Digital Elevation Model and land use and soil maps were also extracted from suitable databases. Geographic information system (GIS) software was applied in combination with SWAT to process the spatial data and simulate the streamflow record. A good correlation between the simulated and observed data during the calibration and validation was found, using statistical measures such as the Nash-Sutcliffe Efficiency (NSE>0.65%), the standard deviation ratio (RSR<0.6), percent bias (±10%≤PBIAS<±15%), and the coefficient of determination (R2=0.78). An estimated potential water yield of 18,671.61mm in the catchment over the period of the simulation suggests that subsistence agriculture is sustainable in the area. The model is suitable for estimating the water yield and water balance in the catchment.
{"title":"A Study on the Applicability of a Swat Model in Predicting the Water Yield and Water Balance of the Upper Ouémé Catchment in the Republic of Benin","authors":"Oluwatosin Olofintoye, Am Ayanshola, A. W. Salami, Akim Idrissiou, J. O. Iji, O. Adeleke","doi":"10.2478/sjce-2022-0007","DOIUrl":"https://doi.org/10.2478/sjce-2022-0007","url":null,"abstract":"Abstract This study investigates the applicability of a Soil and Water Assessment Tool (SWAT) model in predictions of the water yields and water balance of the Upper Oueme catchment in the northern part of the Republic of Benin. Meteorological and hydrological data for a period of 20 years were collected from the Meteorological Agency of Benin and the National Directorate of Water respectively. Spatial data such as a Digital Elevation Model and land use and soil maps were also extracted from suitable databases. Geographic information system (GIS) software was applied in combination with SWAT to process the spatial data and simulate the streamflow record. A good correlation between the simulated and observed data during the calibration and validation was found, using statistical measures such as the Nash-Sutcliffe Efficiency (NSE>0.65%), the standard deviation ratio (RSR<0.6), percent bias (±10%≤PBIAS<±15%), and the coefficient of determination (R2=0.78). An estimated potential water yield of 18,671.61mm in the catchment over the period of the simulation suggests that subsistence agriculture is sustainable in the area. The model is suitable for estimating the water yield and water balance in the catchment.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"30 1","pages":"57 - 66"},"PeriodicalIF":0.4,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47676664","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 Reinforced concrete roof and floor structures have the highest heating temperatures and are exposed to the most difficult conditions during fires that occur in buildings and structures. The standardized fire resistance of hollow-core slabs made of heavy concrete from Portland cement is regulated as REI 45 or REI 60. The aim of the work is to develop a composition of lightweight fire-resistant concrete and architectural engineering for floor slab devices. The composition of lightweight fire-resistant concrete made from expanded clay aggregates and alumina cement was developed as a result of the work. The degree of fire resistance of the lightweight concrete composition with a bulk density of 1475 kg/m3 has been practically determined; i.e., REI 90. The structural solution of the floor slab has been improved; at the same time, we propose to develop a slab with a flat section made of lightweight fire-resistant concrete. Such floor slabs, along with an increase in the fire resistance limit, improve the heat-insulating ability of a floor due to a significant reduction in the coefficient of the thermal conductivity of lightweight concrete.
{"title":"Specific Design Features of Prefabricated Fire-Resistant Floor Slabs Made from Lightweight Concrete","authors":"O. Konoplianyk, Nikolay Kotov, Illia Iliev","doi":"10.2478/sjce-2022-0001","DOIUrl":"https://doi.org/10.2478/sjce-2022-0001","url":null,"abstract":"Abstract Reinforced concrete roof and floor structures have the highest heating temperatures and are exposed to the most difficult conditions during fires that occur in buildings and structures. The standardized fire resistance of hollow-core slabs made of heavy concrete from Portland cement is regulated as REI 45 or REI 60. The aim of the work is to develop a composition of lightweight fire-resistant concrete and architectural engineering for floor slab devices. The composition of lightweight fire-resistant concrete made from expanded clay aggregates and alumina cement was developed as a result of the work. The degree of fire resistance of the lightweight concrete composition with a bulk density of 1475 kg/m3 has been practically determined; i.e., REI 90. The structural solution of the floor slab has been improved; at the same time, we propose to develop a slab with a flat section made of lightweight fire-resistant concrete. Such floor slabs, along with an increase in the fire resistance limit, improve the heat-insulating ability of a floor due to a significant reduction in the coefficient of the thermal conductivity of lightweight concrete.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"30 1","pages":"1 - 7"},"PeriodicalIF":0.4,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44496574","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 Pakistan’s agricultural economy is reliant on the Indus River’s irrigation system, which is fed by the water coming from the great Himalayas-Karakoram Glacier Mountains. Because of hilly terrain areas, the climatic variations have an intense effect on the river flow, especially during the winter and monsoon months. Consequently, significant variations, which are observed annually, result in flooding situations in the monsoon months and reduced flows in the winter season. Thousands of people have lost their lives and massive property destruction has taken place due to disastrous floods that occurred during 2010 and 2016. Past studies have focused on proper water resources and the management of extreme events such as floods and droughts; however, modelling and forecasting based on the various climatic factors and stochastic variations are rare. This paper attempts to forecast Indus River flows using multiple linear regression (MLR), the stochastic time series, the seasonal autoregressive integrated moving average (SARIMA), and its reduced heteroscedasticity model, i.e., SARIMA-GARCH (generalized autoregressive conditional heteroscedasticity) methods at the Kalabagh station. The results show that MLR is best over the short-term; SARIMA is better over the long-term, and SARIMA-GARCH may be superior for a very long-term forecast.
{"title":"The Impact of Climate Change on Stochastic Variations of the Hydrology of the Flow of the Indus River","authors":"M. Yonus, Syed Ahmad Hassan","doi":"10.2478/sjce-2022-0004","DOIUrl":"https://doi.org/10.2478/sjce-2022-0004","url":null,"abstract":"Abstract Pakistan’s agricultural economy is reliant on the Indus River’s irrigation system, which is fed by the water coming from the great Himalayas-Karakoram Glacier Mountains. Because of hilly terrain areas, the climatic variations have an intense effect on the river flow, especially during the winter and monsoon months. Consequently, significant variations, which are observed annually, result in flooding situations in the monsoon months and reduced flows in the winter season. Thousands of people have lost their lives and massive property destruction has taken place due to disastrous floods that occurred during 2010 and 2016. Past studies have focused on proper water resources and the management of extreme events such as floods and droughts; however, modelling and forecasting based on the various climatic factors and stochastic variations are rare. This paper attempts to forecast Indus River flows using multiple linear regression (MLR), the stochastic time series, the seasonal autoregressive integrated moving average (SARIMA), and its reduced heteroscedasticity model, i.e., SARIMA-GARCH (generalized autoregressive conditional heteroscedasticity) methods at the Kalabagh station. The results show that MLR is best over the short-term; SARIMA is better over the long-term, and SARIMA-GARCH may be superior for a very long-term forecast.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"30 1","pages":"33 - 41"},"PeriodicalIF":0.4,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49461794","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. Bilčík, J. Šoltész, Lýdia Leppakorpi Matiašková, K. Gajdosova
Abstract The paper reports the results of a case study for achieving longer service life and increasing the environmental sustainability of concrete silos. Damage mechanisms in concrete silo walls, and respectively in cylindrical structures (e.g., chimneys, cooling towers, and tanks), are widely diverse. The common causes of failures include those due to poor design considerations, construction deficiencies, non-compliance with operational rules and regulations, lack of maintenance, and insufficient and/or corroded reinforcements, together with the environmental conditions affecting the walls. In addition to the ultimate limit state design, temperature-induced cracking may often be underestimated in the design of reinforced concrete silos, leading to premature deterioration and losses in serviceability. Cracks from environmental or service conditions facilitate the ingress of moisture and corrosive agents. Therefore, there is an increased interest in reducing the appearance of cracks and limiting their width. The aim of this paper is to highlight the synergistic effects in the design, construction, and operation of silo walls, particularly under varying environmental influences. The research undertaken indicates that systematic errors can be identified and corrected.
{"title":"Causes of Failures in Circular Concrete Silo Walls, Particularly Under Environmental Influences","authors":"J. Bilčík, J. Šoltész, Lýdia Leppakorpi Matiašková, K. Gajdosova","doi":"10.2478/sjce-2021-0021","DOIUrl":"https://doi.org/10.2478/sjce-2021-0021","url":null,"abstract":"Abstract The paper reports the results of a case study for achieving longer service life and increasing the environmental sustainability of concrete silos. Damage mechanisms in concrete silo walls, and respectively in cylindrical structures (e.g., chimneys, cooling towers, and tanks), are widely diverse. The common causes of failures include those due to poor design considerations, construction deficiencies, non-compliance with operational rules and regulations, lack of maintenance, and insufficient and/or corroded reinforcements, together with the environmental conditions affecting the walls. In addition to the ultimate limit state design, temperature-induced cracking may often be underestimated in the design of reinforced concrete silos, leading to premature deterioration and losses in serviceability. Cracks from environmental or service conditions facilitate the ingress of moisture and corrosive agents. Therefore, there is an increased interest in reducing the appearance of cracks and limiting their width. The aim of this paper is to highlight the synergistic effects in the design, construction, and operation of silo walls, particularly under varying environmental influences. The research undertaken indicates that systematic errors can be identified and corrected.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":" ","pages":"1 - 8"},"PeriodicalIF":0.4,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48624103","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}
KeszeliovÁ Anita, HlavČovÁ Kamila, DanÁČovÁ Michaela, DanÁČovÁ Zuzana, Szolgay Ján
Abstract Due to a changing climate, likely changes to a hydrological regime are one of the primary sources of uncertainty to consider in managing water resources. In Slovakia, a decline in the country’s water resources, combined with a change in the seasonality of runoff and an increase in the extremeness of floods and droughts, represents a potential threat. The objective of the paper was to explore trends in the components of the long-term hydrological balance of various river basins to detect the impacts of changing climate conditions along the Western Carpathians. The proposed method is a comparative exploratory analysis of the hydrological balance of the selected river basins. Temporal changes in the catchments’ average air temperatures, precipitation, runoff, and their differences (considered as an index of the actual evapotranspiration), were estimated for 49 years of data; two non-overlapping sub-periods (25 and 24 years) in the seven river basins were also compared. This work also aims at evaluating the applicability of gridded inputs from the CarpatClim database for modelling the hydrological balance over an extended period. The results document the impact of the rising air temperature and, in part, local physiographic factors on the changes in runoff and actual catchment evapotranspiration.
{"title":"Detection of Changes in the Hydrological Balance in Seven River Basins Along the Western Carpathians in Slovakia","authors":"KeszeliovÁ Anita, HlavČovÁ Kamila, DanÁČovÁ Michaela, DanÁČovÁ Zuzana, Szolgay Ján","doi":"10.2478/sjce-2021-0027","DOIUrl":"https://doi.org/10.2478/sjce-2021-0027","url":null,"abstract":"Abstract Due to a changing climate, likely changes to a hydrological regime are one of the primary sources of uncertainty to consider in managing water resources. In Slovakia, a decline in the country’s water resources, combined with a change in the seasonality of runoff and an increase in the extremeness of floods and droughts, represents a potential threat. The objective of the paper was to explore trends in the components of the long-term hydrological balance of various river basins to detect the impacts of changing climate conditions along the Western Carpathians. The proposed method is a comparative exploratory analysis of the hydrological balance of the selected river basins. Temporal changes in the catchments’ average air temperatures, precipitation, runoff, and their differences (considered as an index of the actual evapotranspiration), were estimated for 49 years of data; two non-overlapping sub-periods (25 and 24 years) in the seven river basins were also compared. This work also aims at evaluating the applicability of gridded inputs from the CarpatClim database for modelling the hydrological balance over an extended period. The results document the impact of the rising air temperature and, in part, local physiographic factors on the changes in runoff and actual catchment evapotranspiration.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"29 1","pages":"49 - 60"},"PeriodicalIF":0.4,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49324642","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 order to ensure the normal use of a junction section of a modern tram, this paper mainly studied a trackside concrete reinforcement scheme. Firstly, the entire non-reinforcement system model with a small radius curve composed of rail, fastener, fastener cover, flexible material, asphalt layer and track slab was established using the ABAQUS finite element software, and the stress distribution and deformation state of the asphalt layers of the non-reinforcement system model under the social vehicle load were analyzed. Then, the whole system model of the concrete reinforcement scheme was founded, and the stress and deformation of the asphalt layers under the same load were investigated. Finally, the calculation results of the concrete reinforcement model were com-pared with those of the non-reinforcement model, and the reinforcement effect was studied. The results show that the concrete reinforcement scheme significantly reduces the stress and deformation of the asphalt layers and improves the stress distribution and deformation state of the asphalt layers.
{"title":"Research on a Trackside Concrete Reinforcement Scheme of a Small Radius Curve at a Junction Section of a Modern Tram","authors":"Zhiqiang Wang, Z. Lei","doi":"10.2478/sjce-2021-0023","DOIUrl":"https://doi.org/10.2478/sjce-2021-0023","url":null,"abstract":"Abstract In order to ensure the normal use of a junction section of a modern tram, this paper mainly studied a trackside concrete reinforcement scheme. Firstly, the entire non-reinforcement system model with a small radius curve composed of rail, fastener, fastener cover, flexible material, asphalt layer and track slab was established using the ABAQUS finite element software, and the stress distribution and deformation state of the asphalt layers of the non-reinforcement system model under the social vehicle load were analyzed. Then, the whole system model of the concrete reinforcement scheme was founded, and the stress and deformation of the asphalt layers under the same load were investigated. Finally, the calculation results of the concrete reinforcement model were com-pared with those of the non-reinforcement model, and the reinforcement effect was studied. The results show that the concrete reinforcement scheme significantly reduces the stress and deformation of the asphalt layers and improves the stress distribution and deformation state of the asphalt layers.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"29 1","pages":"13 - 18"},"PeriodicalIF":0.4,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48604771","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}
Matej Holečka, Martin Jamnický, Matúš Krajčík, R. Rabenseifer
Abstract Extensive roof greenery is one of the ways to reduce the extent and impact of urban heat islands. A prerequisite is the correct design and operation of both the structural and vegetation part of a roof. If adequate maintenance, especially irrigation of the greenery, cannot be ensured, the use of extensive roof greenery can also be counterproductive. The case study to be presented deals with problems of a flat roof with extensive greenery above an underground garage under Central European climate conditions. Infrequent irrigation leads to extremely high temperatures of the substrate in the summer and makes the purpose of this roof pointless. The contribution analyzes the reason for the failure of the vegetation part of the roof, which was claimed to be maintenance-free, points out fire safety issues, and suggests improvements that might be considered in similar cases. At the present time, which is marked by the climate change crisis, there is great societal pressure to build green roofs. However, if it is not possible to ensure their perfect functionality, it is perhaps better to use classically proven types of roofs, but with greater reflectivity of the top layer surface.
{"title":"Extensive Roof Greenery as a Response to Heat Islands: Some Problems","authors":"Matej Holečka, Martin Jamnický, Matúš Krajčík, R. Rabenseifer","doi":"10.2478/sjce-2021-0022","DOIUrl":"https://doi.org/10.2478/sjce-2021-0022","url":null,"abstract":"Abstract Extensive roof greenery is one of the ways to reduce the extent and impact of urban heat islands. A prerequisite is the correct design and operation of both the structural and vegetation part of a roof. If adequate maintenance, especially irrigation of the greenery, cannot be ensured, the use of extensive roof greenery can also be counterproductive. The case study to be presented deals with problems of a flat roof with extensive greenery above an underground garage under Central European climate conditions. Infrequent irrigation leads to extremely high temperatures of the substrate in the summer and makes the purpose of this roof pointless. The contribution analyzes the reason for the failure of the vegetation part of the roof, which was claimed to be maintenance-free, points out fire safety issues, and suggests improvements that might be considered in similar cases. At the present time, which is marked by the climate change crisis, there is great societal pressure to build green roofs. However, if it is not possible to ensure their perfect functionality, it is perhaps better to use classically proven types of roofs, but with greater reflectivity of the top layer surface.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"29 1","pages":"9 - 12"},"PeriodicalIF":0.4,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42648651","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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