Hacer Bilir Özhan, Musa Yildirim, Hamdi Öğüt, H. Öz
Abstract In this study, the microbiologically-induced calcium carbonate precipitation (MICP) method was employed to examine its potential for repairing cracks in concrete. In addition, specific gravity and porosity values were measured to examine the effect of calcite formations on concrete surfaces and microstructures. Bacteria-supplemented concrete repaired cracks up to 0.4 mm wide by filling them with CaCO3. Furthermore, this study not only examined the healing of the width but also the length of cracks. However, as the width of the treated cracks decreased, their length increased. This indicated that the MICP treatment is more effective in a limited crack range. Specific gravity values increased, and porosity values decreased in concrete supplemented with calcifying bacteria. SEM analyses showed that calcite is a bacterial product that forms a very tight bond with a cement gel and that calcite fills visible cracks and voids and creates more of a void-free and undamaged concrete structure.
{"title":"Repair of Cracks in Concrete with the Microbial-Induced Calcite Precipitation (MICP) Method","authors":"Hacer Bilir Özhan, Musa Yildirim, Hamdi Öğüt, H. Öz","doi":"10.2478/sjce-2023-0021","DOIUrl":"https://doi.org/10.2478/sjce-2023-0021","url":null,"abstract":"Abstract In this study, the microbiologically-induced calcium carbonate precipitation (MICP) method was employed to examine its potential for repairing cracks in concrete. In addition, specific gravity and porosity values were measured to examine the effect of calcite formations on concrete surfaces and microstructures. Bacteria-supplemented concrete repaired cracks up to 0.4 mm wide by filling them with CaCO3. Furthermore, this study not only examined the healing of the width but also the length of cracks. However, as the width of the treated cracks decreased, their length increased. This indicated that the MICP treatment is more effective in a limited crack range. Specific gravity values increased, and porosity values decreased in concrete supplemented with calcifying bacteria. SEM analyses showed that calcite is a bacterial product that forms a very tight bond with a cement gel and that calcite fills visible cracks and voids and creates more of a void-free and undamaged concrete structure.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"56 12","pages":"1 - 8"},"PeriodicalIF":0.4,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139191264","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 dynamic penetration test was used to investigate the angle of shear strength of Danube gravel. The correlations for its determination are available in the standards and literature. From the data set of the results, the characteristic value of the angles of shear strength was derived according to the recommended statistical procedure from the second generation of Eurocode 7. The characteristic values of the angle of shear strength were evaluated for well-graded gravels, poor-graded gravels, and gravels with fine-grained particles of the Danube. The correlations, which were based on field tests and considered the genesis of the soil, were compared with laboratory test results and a table of the values from the Slovak standard, which are used for purposes of comparison. In our research we compared the characteristic field values of the angle of shear strength obtained in the laboratory to observe the effect of their genesis on the appropriateness of the correlations used. We conclude with recommendations for the regional correlations and suggest values of the angle of shear strength for the classes of gravels tested.
{"title":"The Angle of the Shear Resistance of Danube Gravel Derived from the Dynamic Penetration Test","authors":"E. Kučová, Jana Frankovská","doi":"10.2478/sjce-2023-0026","DOIUrl":"https://doi.org/10.2478/sjce-2023-0026","url":null,"abstract":"Abstract The dynamic penetration test was used to investigate the angle of shear strength of Danube gravel. The correlations for its determination are available in the standards and literature. From the data set of the results, the characteristic value of the angles of shear strength was derived according to the recommended statistical procedure from the second generation of Eurocode 7. The characteristic values of the angle of shear strength were evaluated for well-graded gravels, poor-graded gravels, and gravels with fine-grained particles of the Danube. The correlations, which were based on field tests and considered the genesis of the soil, were compared with laboratory test results and a table of the values from the Slovak standard, which are used for purposes of comparison. In our research we compared the characteristic field values of the angle of shear strength obtained in the laboratory to observe the effect of their genesis on the appropriateness of the correlations used. We conclude with recommendations for the regional correlations and suggest values of the angle of shear strength for the classes of gravels tested.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"37 12","pages":"38 - 46"},"PeriodicalIF":0.4,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139188830","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 article focuses on an analysis of the indoor climate in a small, newly-built auditorium. Providing optimal indoor climate parameters in the interiors of a university is extremely important for students. Meeting these parameters is essential not only from a physiological point of view, but also to achieve desirable student performances. The parameters of CO2 concentration are also influenced by the air distribution system in a small auditorium. The correct positions of the supply and extract air is very important. The first experimental measurements of CO2 concentration were carried out in a small auditorium in an old building. The natural ventilation of the small auditorium was evaluated. The second experimental measurements of the CO2 concentration were made in a small auditorium in a newly-built building. The ventilation system and the modern air distribution system of the small, newly-built auditorium were evaluated based on the CO2 concentration and the PMV index. A Testo 480 was used for the measurements. The conclusion of this paper contains the recommendations for the design of a newly-built ventilation system in a small auditorium.
{"title":"Analysis of the Indoor Climate in a Small, Newly-Built Auditorium","authors":"Mária Budiaková","doi":"10.2478/sjce-2023-0025","DOIUrl":"https://doi.org/10.2478/sjce-2023-0025","url":null,"abstract":"Abstract The article focuses on an analysis of the indoor climate in a small, newly-built auditorium. Providing optimal indoor climate parameters in the interiors of a university is extremely important for students. Meeting these parameters is essential not only from a physiological point of view, but also to achieve desirable student performances. The parameters of CO2 concentration are also influenced by the air distribution system in a small auditorium. The correct positions of the supply and extract air is very important. The first experimental measurements of CO2 concentration were carried out in a small auditorium in an old building. The natural ventilation of the small auditorium was evaluated. The second experimental measurements of the CO2 concentration were made in a small auditorium in a newly-built building. The ventilation system and the modern air distribution system of the small, newly-built auditorium were evaluated based on the CO2 concentration and the PMV index. A Testo 480 was used for the measurements. The conclusion of this paper contains the recommendations for the design of a newly-built ventilation system in a small auditorium.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"568 ","pages":"34 - 37"},"PeriodicalIF":0.4,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139195274","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 Horizontal green areas are becoming valuable, yet extruded spots, and their constant elimination at the expense of commercial and housing developments is disrupting green infrastructure. Interlocked existing urban structures seldom allow for the creation of parks and larger green open spaces, which could provide a habitat for a wide range of insects, birds, and other small animals. The lack of green spaces causes urban heat islands (UHI) over the cities. Vertical gardens are alternative solutions for urban areas, where it is not possible to increase biodiversity by creating new horizontal green areas. They effectively utilise surfaces that would otherwise be unused and transform them into effective green infrastructure elements. Using the example of the historical city district of Bratislava, i.e., Old Town (Staré Mesto) in Slovakia, we present an alternative approach for resolving the lack of green areas. A case study was conducted to create a map of all the potentially suitable areas for the construction of vertical gardens. We divided these spots into three groups, i.e., walls, columns, and free-standing structures and proposed construction methods for each type. Regarding the placement of potentially suitable areas along the roads connecting important transport hubs with the city centre, we created an original proposal for a district-wide network of vertical gardens as orientation elements for tourists and residents with significant aesthetic merit as well as ecological and hygienic values.
{"title":"The Use of Vertical Gardens as a Network of Urban Navigation Elements with a Positive Impact on Biodiversity and Microclimate in a Dense Urban Environment","authors":"Miriam Zaťovičová, Martina Majorošová","doi":"10.2478/sjce-2023-0027","DOIUrl":"https://doi.org/10.2478/sjce-2023-0027","url":null,"abstract":"Abstract Horizontal green areas are becoming valuable, yet extruded spots, and their constant elimination at the expense of commercial and housing developments is disrupting green infrastructure. Interlocked existing urban structures seldom allow for the creation of parks and larger green open spaces, which could provide a habitat for a wide range of insects, birds, and other small animals. The lack of green spaces causes urban heat islands (UHI) over the cities. Vertical gardens are alternative solutions for urban areas, where it is not possible to increase biodiversity by creating new horizontal green areas. They effectively utilise surfaces that would otherwise be unused and transform them into effective green infrastructure elements. Using the example of the historical city district of Bratislava, i.e., Old Town (Staré Mesto) in Slovakia, we present an alternative approach for resolving the lack of green areas. A case study was conducted to create a map of all the potentially suitable areas for the construction of vertical gardens. We divided these spots into three groups, i.e., walls, columns, and free-standing structures and proposed construction methods for each type. Regarding the placement of potentially suitable areas along the roads connecting important transport hubs with the city centre, we created an original proposal for a district-wide network of vertical gardens as orientation elements for tourists and residents with significant aesthetic merit as well as ecological and hygienic values.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"41 5","pages":"47 - 56"},"PeriodicalIF":0.4,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139192169","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 study evaluates the performance of concrete under the effect of the addition of non-straight fibers recovered during the machining of steel parts and then studies the effect of the addition of corrugated fibers (chips) on their behavior in direct traction of the fiber concrete. In order to characterize the mechanical behavior and tearing of these fibers, three lengths of fibers were used (4 cm, 5 cm, and 6 cm); for each length we varied the percentage by volume (0.3%, 0.5%, 0.8%, 1%, and 1.2%). To make a comparative study, a second series of tests was carried out with control concrete (BT) without any fibers of the same composition. The results of the tests carried out indicate that the resistance and stiffness are significantly improved and that the fibers imparted significant ductility to the material compared to the control concrete. It was also observed that the percentage of fibers significantly influences the appearance of cracks. Moreover, with an increase in the percentage of fibers from 0.3% to 0.8%, the resistance increases, but beyond a content of 0.8%, the mechanical characteristics decrease.
{"title":"Effect of Recovered Fibers on the Behavior of Concrete in Tension","authors":"Djamal Atlaoui, A. Adjrad, Y. Bouafia","doi":"10.2478/sjce-2023-0024","DOIUrl":"https://doi.org/10.2478/sjce-2023-0024","url":null,"abstract":"Abstract This study evaluates the performance of concrete under the effect of the addition of non-straight fibers recovered during the machining of steel parts and then studies the effect of the addition of corrugated fibers (chips) on their behavior in direct traction of the fiber concrete. In order to characterize the mechanical behavior and tearing of these fibers, three lengths of fibers were used (4 cm, 5 cm, and 6 cm); for each length we varied the percentage by volume (0.3%, 0.5%, 0.8%, 1%, and 1.2%). To make a comparative study, a second series of tests was carried out with control concrete (BT) without any fibers of the same composition. The results of the tests carried out indicate that the resistance and stiffness are significantly improved and that the fibers imparted significant ductility to the material compared to the control concrete. It was also observed that the percentage of fibers significantly influences the appearance of cracks. Moreover, with an increase in the percentage of fibers from 0.3% to 0.8%, the resistance increases, but beyond a content of 0.8%, the mechanical characteristics decrease.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"292 7","pages":"26 - 33"},"PeriodicalIF":0.4,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139193005","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 Reinforcing soft soils with good drainage and load-bearing material is a common practice in the construction of embankments. Stone columns are among the granular materials that accelerate consolidation settlements due to their high drainage capacities. This study aims to investigate the behavior of an embankment on stone column-reinforced soft soil. The embankment was analyzed using the Plaxis 2D Finite Element Method. The columns were converted into equivalent walls using the plane strain conversion method. This method was validated with field measurement results from previous studies and showed good agreement. According to the research findings, stone columns significantly reduced deformations and improved consolidation. For instance, the ultimate settlement was decreased from 54.3 mm to 33.1 mm for 10% and 20% area replacement ratios, respectively. As the safety analysis verified, basal geosynthetics contributed substantially to the embankment’s stability. Furthermore, the safety factor values increased for all stages of the construction, and the global safety factor increased at the end of the construction. Stone columns and basal geogrid-reinforced soft soil can reduce settlement and increase the stability of an embankment.
{"title":"Behavior of an Embankment on Stone Column-Reinforced Soft Soil","authors":"T. A. Wassie, Gökhan Demir","doi":"10.2478/sjce-2023-0022","DOIUrl":"https://doi.org/10.2478/sjce-2023-0022","url":null,"abstract":"Abstract Reinforcing soft soils with good drainage and load-bearing material is a common practice in the construction of embankments. Stone columns are among the granular materials that accelerate consolidation settlements due to their high drainage capacities. This study aims to investigate the behavior of an embankment on stone column-reinforced soft soil. The embankment was analyzed using the Plaxis 2D Finite Element Method. The columns were converted into equivalent walls using the plane strain conversion method. This method was validated with field measurement results from previous studies and showed good agreement. According to the research findings, stone columns significantly reduced deformations and improved consolidation. For instance, the ultimate settlement was decreased from 54.3 mm to 33.1 mm for 10% and 20% area replacement ratios, respectively. As the safety analysis verified, basal geosynthetics contributed substantially to the embankment’s stability. Furthermore, the safety factor values increased for all stages of the construction, and the global safety factor increased at the end of the construction. Stone columns and basal geogrid-reinforced soft soil can reduce settlement and increase the stability of an embankment.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"56 5","pages":"9 - 15"},"PeriodicalIF":0.4,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139190743","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 Algeria is currently undergoing an evolution in civil engineering, which has resulted in a higher use of aggregates, especially sand. This study contributes to the development of locally produced materials. Its goal is to explore how the type of sand and waste marble powder (WMP), which can be used as a partial replacement of cement and aluminum powder (Al) with different percentages as an expansive agent, can affect physico-mechanical properties such as the bulk density and mechanical strength at 28 and 90 days, as well as the thermal conductivity of lightweight cellular concrete. Non-autoclaved cellular concretes (CC) were investigated based on three types of sand, i.e., sea sand (SS), river sand (RS), and waste marble sand (WMS); a hydraulic binder (a mix of cement and waste marble powder), and aluminum powder. The experimental results indicate that the nature and particle size distribution of the sand used had an impact on the properties of the CCs. Furthermore, it can be seen that the increased aluminum contents decrease the density, mechanical strength, and thermal characteristics of the CCs. Using 10-15% WMP as a cement substitute improves the mechanical strength, offers better thermal conductivity values, and contributes to sustainable development by developing a new class of environmentally friendly cellular concrete.
摘要 阿尔及利亚目前正在经历土木工程的演变，这导致了对集料，尤其是沙子的更多使用。这项研究有助于开发本地生产的材料。砂和废大理石粉（WMP）可部分替代水泥，铝粉（Al）可作为膨胀剂，其不同的比例会影响轻质蜂窝混凝土的物理机械性能，如 28 天和 90 天的体积密度和机械强度，以及导热性能。研究了基于三种砂（即海砂（SS）、河砂（RS）和废大理石砂（WMS））、水力粘结剂（水泥和废大理石粉的混合物）和铝粉的非蒸压蜂窝混凝土（CC）。实验结果表明，所用沙子的性质和粒度分布对 CC 的性能有影响。此外，还可以看出铝含量的增加会降低 CC 的密度、机械强度和热特性。使用 10-15% 的 WMP 作为水泥替代品可以提高机械强度，提供更好的导热值，并通过开发新型环保蜂窝混凝土促进可持续发展。
{"title":"Experimental Contribution to Study the Physico-Mechanical and Thermal Properties of Lightweight Cellular Concrete Prepared With Different Types of Sand and Waste Marble Powder","authors":"Moufida Bourema, I. Goual, A. Ferhat","doi":"10.2478/sjce-2023-0023","DOIUrl":"https://doi.org/10.2478/sjce-2023-0023","url":null,"abstract":"Abstract Algeria is currently undergoing an evolution in civil engineering, which has resulted in a higher use of aggregates, especially sand. This study contributes to the development of locally produced materials. Its goal is to explore how the type of sand and waste marble powder (WMP), which can be used as a partial replacement of cement and aluminum powder (Al) with different percentages as an expansive agent, can affect physico-mechanical properties such as the bulk density and mechanical strength at 28 and 90 days, as well as the thermal conductivity of lightweight cellular concrete. Non-autoclaved cellular concretes (CC) were investigated based on three types of sand, i.e., sea sand (SS), river sand (RS), and waste marble sand (WMS); a hydraulic binder (a mix of cement and waste marble powder), and aluminum powder. The experimental results indicate that the nature and particle size distribution of the sand used had an impact on the properties of the CCs. Furthermore, it can be seen that the increased aluminum contents decrease the density, mechanical strength, and thermal characteristics of the CCs. Using 10-15% WMP as a cement substitute improves the mechanical strength, offers better thermal conductivity values, and contributes to sustainable development by developing a new class of environmentally friendly cellular concrete.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"27 9","pages":"16 - 25"},"PeriodicalIF":0.4,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139192493","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 Precast reinforced concrete constructions meet the requirements of industrialization, high manufacturability, and cost-effectiveness at a reasonably high level. The ribs in constructions perform load-bearing functions, and the slab part performs enclosing functions. Often before the installation of such structures at a construction site, they are mounted from assembly elements. The overall dimensions of the elements are limited by transportation requirements. During such an aggregated mounting, the assembly units work according to a calculation scheme that differs from an operational scheme. The structural nonlinearity of ribbed reinforced concrete slabs during transportation, mounting, and installation, and the operation of a combined spatial covering panel were investigated in this paper. The effects were identified, and a rational design of nodes connecting the individual prefabricated units into a spatial structure was developed. With the help of these nodes, it is possible to create unloading support moments, which will reduce the internal forces in the design cross-sections. The effects of changes in the width of the reinforced concrete slab shelves on the internal forces of the load-bearing ribs of a wall and a roof panel were investigated.
{"title":"Calculation of the Constructive Nonlinearity of Ribbed Reinforced Concrete Slabs of Self-Stressed Covering Panels","authors":"Anton Hasenko, Volodymyr Semko, Serhii Skliarenko","doi":"10.2478/sjce-2023-0016","DOIUrl":"https://doi.org/10.2478/sjce-2023-0016","url":null,"abstract":"Abstract Precast reinforced concrete constructions meet the requirements of industrialization, high manufacturability, and cost-effectiveness at a reasonably high level. The ribs in constructions perform load-bearing functions, and the slab part performs enclosing functions. Often before the installation of such structures at a construction site, they are mounted from assembly elements. The overall dimensions of the elements are limited by transportation requirements. During such an aggregated mounting, the assembly units work according to a calculation scheme that differs from an operational scheme. The structural nonlinearity of ribbed reinforced concrete slabs during transportation, mounting, and installation, and the operation of a combined spatial covering panel were investigated in this paper. The effects were identified, and a rational design of nodes connecting the individual prefabricated units into a spatial structure was developed. With the help of these nodes, it is possible to create unloading support moments, which will reduce the internal forces in the design cross-sections. The effects of changes in the width of the reinforced concrete slab shelves on the internal forces of the load-bearing ribs of a wall and a roof panel were investigated.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135588658","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 production of plastics and the associated increasing amount of plastic waste is currently a serious environmental problem that has a negative impact on the environment. It is necessary to develop new methods of recycling and also solutions for the further use of already recycled plastics. Thus far, a lot of research has been devoted to this issue, which focuses on the effective recycling and reuse of recycled plastic in the construction sector. One of the possibilities is the application of a filler substitute in concrete, which is an economically and ecologically advantageous solution that ensures optimal thermal insulation and acoustic properties. The aim of this study was to analyze the potential replacement of conventional aggregates in lightweight concrete, with a filler made of recycled plastic with a lower bulk density. In the research, wood chips were used in combination with recycled waste fillers including polystyrene (SE), polyethene (SP), and polyurethane foam (SU) in ratios of 1:3, 1:1, and 3:1 as an alternative to conventional filler. Concrete composites from these materials were prepared and characterized by their bulk density, thermal conductivity and compressive strength parameters.
{"title":"Preparation and Modification of Chip-Cement Wooden Composites Based on Recycled Plastics","authors":"Terézia Cabanová","doi":"10.2478/sjce-2023-0020","DOIUrl":"https://doi.org/10.2478/sjce-2023-0020","url":null,"abstract":"Abstract The production of plastics and the associated increasing amount of plastic waste is currently a serious environmental problem that has a negative impact on the environment. It is necessary to develop new methods of recycling and also solutions for the further use of already recycled plastics. Thus far, a lot of research has been devoted to this issue, which focuses on the effective recycling and reuse of recycled plastic in the construction sector. One of the possibilities is the application of a filler substitute in concrete, which is an economically and ecologically advantageous solution that ensures optimal thermal insulation and acoustic properties. The aim of this study was to analyze the potential replacement of conventional aggregates in lightweight concrete, with a filler made of recycled plastic with a lower bulk density. In the research, wood chips were used in combination with recycled waste fillers including polystyrene (SE), polyethene (SP), and polyurethane foam (SU) in ratios of 1:3, 1:1, and 3:1 as an alternative to conventional filler. Concrete composites from these materials were prepared and characterized by their bulk density, thermal conductivity and compressive strength parameters.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135588670","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 article presents a method for the intensification of a tailings pond. A tailings pond serves for the hydraulic storage of silt-sand waste arising during a flotation treatment and the processing of polymetallic ores. The intensification of the tailings pond consisted of raising its dam system to increase its accumulation space. The total proposed height of the tailings pond dam system after its elevation will be 60 m. The structural and shape arrangement of the dam in the dam system of the tailings pond was the result of a stability analysis of the state of the tailings pond before and after the dam system was raised. The article presents the results of experimental verifications of the geomaterial properties that form quasi-homogeneous units of the tailings pond (subsoil, dam system, and sediment) that serve as the inputs for stability analyses. New limiting and critical water levels are modelled based on the stability analysis for the intensified dam system of the tailings pond, taking into account the standard requirements for its overall stability.
{"title":"Raising of Embankment of an Ore Tailings Pond and an Analysis of its Stability","authors":"Dagmar Chropeňová, Ivan Slávik","doi":"10.2478/sjce-2023-0017","DOIUrl":"https://doi.org/10.2478/sjce-2023-0017","url":null,"abstract":"Abstract The article presents a method for the intensification of a tailings pond. A tailings pond serves for the hydraulic storage of silt-sand waste arising during a flotation treatment and the processing of polymetallic ores. The intensification of the tailings pond consisted of raising its dam system to increase its accumulation space. The total proposed height of the tailings pond dam system after its elevation will be 60 m. The structural and shape arrangement of the dam in the dam system of the tailings pond was the result of a stability analysis of the state of the tailings pond before and after the dam system was raised. The article presents the results of experimental verifications of the geomaterial properties that form quasi-homogeneous units of the tailings pond (subsoil, dam system, and sediment) that serve as the inputs for stability analyses. New limiting and critical water levels are modelled based on the stability analysis for the intensified dam system of the tailings pond, taking into account the standard requirements for its overall stability.","PeriodicalId":43574,"journal":{"name":"Slovak Journal of Civil Engineering","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135588672","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：