Pub Date : 2023-07-01DOI: 10.28991/cej-2023-09-07-01
M. Al-Ansari, M. Afzal
This paper presents an analytical method for generating the interaction diagrams of uniaxially reinforced concrete (RC) columns that are subjected to four-face heating. Twenty-one (21) specimens obtained from previous case studies that were subjected to four-face heating (with different fire test times ranging from 63 to 356 fire minutes) are used to validate the proposed uniaxial interaction charts. The results obtained from the case studies and from the proposed charts are also compared with the finite element software (FIN EC). The 500°C isotherm as well as the zone method are used in the computer software program to find the required load capacities. The proposed method's values fall within the range of values obtained from laboratory tests and computer software, which suggests its validity. Also, the zone method in FIN-EC software is reliable for evaluating load-bearing capacity, while the 500°C method is useful in situations with shorter fire times. The results obtained provide a valuable tool for designing and evaluating structures that may be exposed to fire. Nonetheless, the study is restricted by its concentration on a particular type of column under four-face heating, which may reduce its relevance to other types of structures and heating situations. Doi: 10.28991/CEJ-2023-09-07-01 Full Text: PDF
{"title":"Four-Face Heated Uniaxial Reinforced Concrete Columns Interaction Charts","authors":"M. Al-Ansari, M. Afzal","doi":"10.28991/cej-2023-09-07-01","DOIUrl":"https://doi.org/10.28991/cej-2023-09-07-01","url":null,"abstract":"This paper presents an analytical method for generating the interaction diagrams of uniaxially reinforced concrete (RC) columns that are subjected to four-face heating. Twenty-one (21) specimens obtained from previous case studies that were subjected to four-face heating (with different fire test times ranging from 63 to 356 fire minutes) are used to validate the proposed uniaxial interaction charts. The results obtained from the case studies and from the proposed charts are also compared with the finite element software (FIN EC). The 500°C isotherm as well as the zone method are used in the computer software program to find the required load capacities. The proposed method's values fall within the range of values obtained from laboratory tests and computer software, which suggests its validity. Also, the zone method in FIN-EC software is reliable for evaluating load-bearing capacity, while the 500°C method is useful in situations with shorter fire times. The results obtained provide a valuable tool for designing and evaluating structures that may be exposed to fire. Nonetheless, the study is restricted by its concentration on a particular type of column under four-face heating, which may reduce its relevance to other types of structures and heating situations. Doi: 10.28991/CEJ-2023-09-07-01 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84750396","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}
Pub Date : 2023-07-01DOI: 10.28991/cej-2023-09-07-03
Wisam Hamzah Mohammed, S. Shambina, H. Ammash
The target of this study is to reduce the impact of initial imperfection on the nonlinear dynamical performance of laminated composite plates by taking advantage of the orthotropic characteristics of laminated composite plates by changing carbon fiber sawing in the mass matrix and fiber orientation with different patterns and studying the effect of this optimization without and with initial imperfection (Wo) and different aspect ratios (W/L) and various boundary conditions through analyzing the load-displacement responses for plates under axial in-plane compressive loads by using the FORTRAN 94 programming language. Von-Karman's assumptions are utilized to include geometric nonlinearity for nine node isoperimetric quadrilateral components with five degrees of freedom into the structural model, which is based on first-order shear deformation theory. The Newmark’s implicit time integration method and Newton-Raphson iteration concurrently are employed to solve the nonlinear governing equation in conjunction. The study proved the effectiveness of the carbon fiber's varying geometric distribution and the difference in its directions in reducing the negative effects of the initial imperfection on the large elastic-plastic displacement and critical buckling. To highlight the veracity of the results, some of them have been validated against those found in the literature review. Doi: 10.28991/CEJ-2023-09-07-03 Full Text: PDF
{"title":"Reducing Effects of Initial Imperfection by Investment in the Orthotropic Characteristics of Laminated Composite Plate","authors":"Wisam Hamzah Mohammed, S. Shambina, H. Ammash","doi":"10.28991/cej-2023-09-07-03","DOIUrl":"https://doi.org/10.28991/cej-2023-09-07-03","url":null,"abstract":"The target of this study is to reduce the impact of initial imperfection on the nonlinear dynamical performance of laminated composite plates by taking advantage of the orthotropic characteristics of laminated composite plates by changing carbon fiber sawing in the mass matrix and fiber orientation with different patterns and studying the effect of this optimization without and with initial imperfection (Wo) and different aspect ratios (W/L) and various boundary conditions through analyzing the load-displacement responses for plates under axial in-plane compressive loads by using the FORTRAN 94 programming language. Von-Karman's assumptions are utilized to include geometric nonlinearity for nine node isoperimetric quadrilateral components with five degrees of freedom into the structural model, which is based on first-order shear deformation theory. The Newmark’s implicit time integration method and Newton-Raphson iteration concurrently are employed to solve the nonlinear governing equation in conjunction. The study proved the effectiveness of the carbon fiber's varying geometric distribution and the difference in its directions in reducing the negative effects of the initial imperfection on the large elastic-plastic displacement and critical buckling. To highlight the veracity of the results, some of them have been validated against those found in the literature review. Doi: 10.28991/CEJ-2023-09-07-03 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82461388","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}
Pub Date : 2023-07-01DOI: 10.28991/cej-2023-09-07-02
A. F. Setiawan, A. K. Santoso, M. F. Darmawan, A. D. Adi, S. Ismanti
Slab-on-pile SOP viaducts have been constructed on several highways and railways in Indonesia, but there are certain doubts about some practical structural seismic design concepts. Therefore, this study aims to investigate the seismic performance of a single spun pile column for the SOP viaduct using nonlinear analysis. The essential variables used include the effect of top pile reinforced concrete infill treatment, soil-pile structure interaction (SPSI), and different response modification factors (R). Moreover, the single spun pile column was designed as a macro model with a force-based beam-column element having a fiber section in the plastic hinge. The static pushover analysis and quasi-static cyclic were also conducted to determine the displacement limit state and the equal viscous damping, respectively. Furthermore, seven pairs of ground motion excitations were used to investigate seismic performance in line with ASCE 7-10 and ASCE 61-14. The results showed that the implementation of the top-pile reinforced concrete infill treatment slightly reduced seismic response but evoked more severe pile curvature in the embedded zone. In addition, the behavior and seismic performance were slightly better than those without treatment when considering the SPSI. This study recommends the spun pile column for the SOP viaduct with a response modification factor of 1.5 to avoid probable brittle failure occurrence under earthquake load. Doi: 10.28991/CEJ-2023-09-07-02 Full Text: PDF
{"title":"Nonlinear Analysis for Investigating Seismic Performance of a Spun Pile-Column of Viaduct Structure","authors":"A. F. Setiawan, A. K. Santoso, M. F. Darmawan, A. D. Adi, S. Ismanti","doi":"10.28991/cej-2023-09-07-02","DOIUrl":"https://doi.org/10.28991/cej-2023-09-07-02","url":null,"abstract":"Slab-on-pile SOP viaducts have been constructed on several highways and railways in Indonesia, but there are certain doubts about some practical structural seismic design concepts. Therefore, this study aims to investigate the seismic performance of a single spun pile column for the SOP viaduct using nonlinear analysis. The essential variables used include the effect of top pile reinforced concrete infill treatment, soil-pile structure interaction (SPSI), and different response modification factors (R). Moreover, the single spun pile column was designed as a macro model with a force-based beam-column element having a fiber section in the plastic hinge. The static pushover analysis and quasi-static cyclic were also conducted to determine the displacement limit state and the equal viscous damping, respectively. Furthermore, seven pairs of ground motion excitations were used to investigate seismic performance in line with ASCE 7-10 and ASCE 61-14. The results showed that the implementation of the top-pile reinforced concrete infill treatment slightly reduced seismic response but evoked more severe pile curvature in the embedded zone. In addition, the behavior and seismic performance were slightly better than those without treatment when considering the SPSI. This study recommends the spun pile column for the SOP viaduct with a response modification factor of 1.5 to avoid probable brittle failure occurrence under earthquake load. Doi: 10.28991/CEJ-2023-09-07-02 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91317476","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}
Pub Date : 2023-07-01DOI: 10.28991/cej-2023-09-07-015
D. R. Tama, L. Limantara, E. Suhartanto, Y. P. Devia
This research intends to predict the discharge (run-off) from rainfall for which the model is built using W-flow. The research location is in the Gajah Mungkur reservoir (Wonogiri) in Indonesia. The estimation of reservoir inflow has an important role, mainly in the scheme of reservoir operation and management. However, the heterogeneity of complex spatial and temporal patterns of rainfall and also the physiographic context of a watershed cause the development of a model of real-time run-off and rainfall that can accurately predict the reservoir inflow to become a challenge in the development of water resources. In relation to the analysis and prediction of rainfall, the constraint and problem that is still often faced is the minimal availability of observed rainfall data spatially as well as temporally; the time series of rainfall data is not long and complete enough; and the number of rainfall stations is less evenly distributed. The methodology consists of carrying out the literature study, collecting as much rainfall data as possible to build a W flow model, then carrying out the model calibration and analyzing the prediction of real-time reservoir inflow for operation. The result shows that the dependable discharge of the Wonogiri watershed shows that there are two peak discharges, which happened on February II (the second half of February) and December II (the second half of December). However, the discharge is decreasing in July and reaching its lowest level in October II (the second half of October). Doi: 10.28991/CEJ-2023-09-07-015 Full Text: PDF
{"title":"The Reliability of W-flow Run-off-Rainfall Model in Predicting Rainfall to the Discharge","authors":"D. R. Tama, L. Limantara, E. Suhartanto, Y. P. Devia","doi":"10.28991/cej-2023-09-07-015","DOIUrl":"https://doi.org/10.28991/cej-2023-09-07-015","url":null,"abstract":"This research intends to predict the discharge (run-off) from rainfall for which the model is built using W-flow. The research location is in the Gajah Mungkur reservoir (Wonogiri) in Indonesia. The estimation of reservoir inflow has an important role, mainly in the scheme of reservoir operation and management. However, the heterogeneity of complex spatial and temporal patterns of rainfall and also the physiographic context of a watershed cause the development of a model of real-time run-off and rainfall that can accurately predict the reservoir inflow to become a challenge in the development of water resources. In relation to the analysis and prediction of rainfall, the constraint and problem that is still often faced is the minimal availability of observed rainfall data spatially as well as temporally; the time series of rainfall data is not long and complete enough; and the number of rainfall stations is less evenly distributed. The methodology consists of carrying out the literature study, collecting as much rainfall data as possible to build a W flow model, then carrying out the model calibration and analyzing the prediction of real-time reservoir inflow for operation. The result shows that the dependable discharge of the Wonogiri watershed shows that there are two peak discharges, which happened on February II (the second half of February) and December II (the second half of December). However, the discharge is decreasing in July and reaching its lowest level in October II (the second half of October). Doi: 10.28991/CEJ-2023-09-07-015 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85850114","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}
Pub Date : 2023-07-01DOI: 10.28991/cej-2023-09-07-016
Nasser Khalaf, Thair Shareef, M. Al-Mukhtar
In arid and semi-arid regions particularly vulnerable to climate change, optimizing the long-term operation of multi-purpose reservoirs is paramount. This study derived an optimum two-dimensional rule curve to jointly operate the parallel reservoirs of Mosul and Dukan, Northern Iraq. A hybridized optimization technique combining conventional dynamic programming with the shuffled complex evolution algorithm (SCE-UA) was developed to solve this problem. The results showed that the proportion of normal water supply areas increased from the beginning of the flood season (October) to its highest levels in April (58.77% of the total water supply area). The proportion decreased to its lowest in September (25.04% of the total water supply area). The newly derived 2D rule cure was compared with the current operation policy and was found to optimize the amount of water shortage by 21.1% during the operational period. It also reduced the shortage period and avoided catastrophic water shortages during droughts. In addition, the developed model optimized the amounts of water more than the joint water requirements, suffering from a significant deficit in meeting the demand during some months of the operational years. As a result, the storage in each reservoir was improved and thence can be adapted to face water shortages during future climate changes. This study proved the new hybridized model's applicability and can serve as a tool for sustainable water management. Doi: 10.28991/CEJ-2023-09-07-016 Full Text: PDF
{"title":"Derivation of Optimal Two Dimensional Rule Curve for Dualistic Reservoir Water-Supply System","authors":"Nasser Khalaf, Thair Shareef, M. Al-Mukhtar","doi":"10.28991/cej-2023-09-07-016","DOIUrl":"https://doi.org/10.28991/cej-2023-09-07-016","url":null,"abstract":"In arid and semi-arid regions particularly vulnerable to climate change, optimizing the long-term operation of multi-purpose reservoirs is paramount. This study derived an optimum two-dimensional rule curve to jointly operate the parallel reservoirs of Mosul and Dukan, Northern Iraq. A hybridized optimization technique combining conventional dynamic programming with the shuffled complex evolution algorithm (SCE-UA) was developed to solve this problem. The results showed that the proportion of normal water supply areas increased from the beginning of the flood season (October) to its highest levels in April (58.77% of the total water supply area). The proportion decreased to its lowest in September (25.04% of the total water supply area). The newly derived 2D rule cure was compared with the current operation policy and was found to optimize the amount of water shortage by 21.1% during the operational period. It also reduced the shortage period and avoided catastrophic water shortages during droughts. In addition, the developed model optimized the amounts of water more than the joint water requirements, suffering from a significant deficit in meeting the demand during some months of the operational years. As a result, the storage in each reservoir was improved and thence can be adapted to face water shortages during future climate changes. This study proved the new hybridized model's applicability and can serve as a tool for sustainable water management. Doi: 10.28991/CEJ-2023-09-07-016 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"568 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79679831","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}
Pub Date : 2023-07-01DOI: 10.28991/cej-2023-09-07-07
O. Al-Omari, Ahmad Alkhdor, M. Al-Rawashdeh, M. R. Al-Ruwaishedi, S. AL-Rawashdeh
The construction industry is a significant source of greenhouse gas emissions, and there is a growing global interest in reducing the environmental impact of carbon dioxide emissions associated with building construction and operation. Concrete, the most commonly used material in construction, is known to release a substantial amount of environmentally harmful waste throughout its life cycle, including production, construction, operation, and demolition. The worldwide production and consumption of concrete contribute to approximately 5% of all human-related CO2 emissions each year. To assess the carbon footprint of concrete manufacturing and its application in construction projects, a comprehensive approach called life cycle assessment (LCA) is necessary. This paper presents a new process-based LCA approach to analyze carbon emissions and evaluate the carbon footprint of concrete from raw material extraction to the end-of-life stage. To address carbon emissions throughout the life cycle of concrete structures in the Middle East, the study adopts a case study approach, focusing on selected concrete structures in Jordan. The findings from these case studies highlight that the operational phase of concrete structures is the primary contributor to carbon emissions. By thoroughly examining the carbon cycle within structures and their interactions with the surrounding ecosystem, significant reductions in CO2 emissions, environmental deterioration, and its consequences can be achieved. Doi: 10.28991/CEJ-2023-09-07-07 Full Text: PDF
{"title":"Evaluating Carbon Footprint in the Life Cycle Design of Residential Concrete Structures in Jordan","authors":"O. Al-Omari, Ahmad Alkhdor, M. Al-Rawashdeh, M. R. Al-Ruwaishedi, S. AL-Rawashdeh","doi":"10.28991/cej-2023-09-07-07","DOIUrl":"https://doi.org/10.28991/cej-2023-09-07-07","url":null,"abstract":"The construction industry is a significant source of greenhouse gas emissions, and there is a growing global interest in reducing the environmental impact of carbon dioxide emissions associated with building construction and operation. Concrete, the most commonly used material in construction, is known to release a substantial amount of environmentally harmful waste throughout its life cycle, including production, construction, operation, and demolition. The worldwide production and consumption of concrete contribute to approximately 5% of all human-related CO2 emissions each year. To assess the carbon footprint of concrete manufacturing and its application in construction projects, a comprehensive approach called life cycle assessment (LCA) is necessary. This paper presents a new process-based LCA approach to analyze carbon emissions and evaluate the carbon footprint of concrete from raw material extraction to the end-of-life stage. To address carbon emissions throughout the life cycle of concrete structures in the Middle East, the study adopts a case study approach, focusing on selected concrete structures in Jordan. The findings from these case studies highlight that the operational phase of concrete structures is the primary contributor to carbon emissions. By thoroughly examining the carbon cycle within structures and their interactions with the surrounding ecosystem, significant reductions in CO2 emissions, environmental deterioration, and its consequences can be achieved. Doi: 10.28991/CEJ-2023-09-07-07 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"224 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85436898","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}
Pub Date : 2023-07-01DOI: 10.28991/cej-2023-09-07-013
S. B. Kharmale, Pramod S. Sathe, Y. Kolekar
Concrete has a high degree of fire resistance at moderate temperatures. High temperatures, however, cause concrete to lose its stiffness and strength. The effects of cooling techniques and retrofitting on the strength of concrete exposed to high temperatures have not been synchronized in previous studies. This experimental research aims to evaluate the effect of cooling conditions and the effectiveness of retrofitting concrete subjected to elevated temperatures. Four types of concrete: M 20 normal concrete (NC); M 20 metakaolin concrete (MC); M 40 standard concrete (SC); and M 40 self-compacting concrete (SCC) are considered in this study. A total of 864 samples consisting of cube, beam, and cylinder specimens are subjected to sustained elevated temperatures of 400oC, 600oC, and 800oC for 2 hours rating. The weight and strength of half of the heat-damaged samples are assessed following natural air cooling (NAC) and water jet cooling (WJC). The remaining 50% of samples retrofitted with carbon fiber reinforced polymer (CFRP) are tested to evaluate the upgraded strength. The experimental findings demonstrate that water jet cooling (WJC) causes more strength degradation, and CFRP proves to be effective in restoring the strength of heat-deteriorated specimens. Overall, self-compacting concrete (SCC) has shown high resistance to elevated temperatures. Doi: 10.28991/CEJ-2023-09-07-013 Full Text: PDF
{"title":"Effect of Cooling Conditions, Retrofitting on Strength of Concrete Subjected to Elevated Temperature","authors":"S. B. Kharmale, Pramod S. Sathe, Y. Kolekar","doi":"10.28991/cej-2023-09-07-013","DOIUrl":"https://doi.org/10.28991/cej-2023-09-07-013","url":null,"abstract":"Concrete has a high degree of fire resistance at moderate temperatures. High temperatures, however, cause concrete to lose its stiffness and strength. The effects of cooling techniques and retrofitting on the strength of concrete exposed to high temperatures have not been synchronized in previous studies. This experimental research aims to evaluate the effect of cooling conditions and the effectiveness of retrofitting concrete subjected to elevated temperatures. Four types of concrete: M 20 normal concrete (NC); M 20 metakaolin concrete (MC); M 40 standard concrete (SC); and M 40 self-compacting concrete (SCC) are considered in this study. A total of 864 samples consisting of cube, beam, and cylinder specimens are subjected to sustained elevated temperatures of 400oC, 600oC, and 800oC for 2 hours rating. The weight and strength of half of the heat-damaged samples are assessed following natural air cooling (NAC) and water jet cooling (WJC). The remaining 50% of samples retrofitted with carbon fiber reinforced polymer (CFRP) are tested to evaluate the upgraded strength. The experimental findings demonstrate that water jet cooling (WJC) causes more strength degradation, and CFRP proves to be effective in restoring the strength of heat-deteriorated specimens. Overall, self-compacting concrete (SCC) has shown high resistance to elevated temperatures. Doi: 10.28991/CEJ-2023-09-07-013 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80262515","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}
Pub Date : 2023-07-01DOI: 10.28991/cej-2023-09-07-05
Vu Nguyen Nguyen, V. Cao
In this study, experiments were performed on carbon fiber reinforced polymer (CFRP) retrofitted postfire reinforced concrete (RC) beams, followed by theoretical analyzes. Experiments were conducted on eleven RC beams, which were exposed to different fire durations and retrofitted with CFRP in flexure and shear. The experimental results indicated that fire shifted the flexure failure to the flexure-shear failure of postfire RC beams. CFRP retrofitted postfire RC beams experienced progressive peeling-off failure. FRP retrofitting significantly increased the yield deflection by 58.2−97.3% but decreased the ultimate deflection by 43.0−55.5% compared with that of the control beam. Consequently, the ductility was reduced by 69.7−74.7%, categorized as low ductility. CFRP retrofitting successfully increased the strengths of 30-min postfire beams by up to 23.1% higher than those of the control beam. Fire significantly decreased the stiffness of postfire beams by 46.4−49.2% compared with that of the control beam, whereas CFRP retrofitting did not fully recover the stiffness of postfire beams. Finally, a simple model of the moment capacity of postfire beams without/with CFRP retrofits was developed based on the practicability of limited data feasibly obtained from real fires. The proposed model, with its simplicity, practicability, and reasonable accuracy, can be a useful tool for structural engineers in the FRP retrofitting of postfire RC structures. Doi: 10.28991/CEJ-2023-09-07-05 Full Text: PDF
{"title":"Experimental and Analytical Study on Postfire Reinforced Concrete Beams Retrofitted with CFRP in Flexure and Shear","authors":"Vu Nguyen Nguyen, V. Cao","doi":"10.28991/cej-2023-09-07-05","DOIUrl":"https://doi.org/10.28991/cej-2023-09-07-05","url":null,"abstract":"In this study, experiments were performed on carbon fiber reinforced polymer (CFRP) retrofitted postfire reinforced concrete (RC) beams, followed by theoretical analyzes. Experiments were conducted on eleven RC beams, which were exposed to different fire durations and retrofitted with CFRP in flexure and shear. The experimental results indicated that fire shifted the flexure failure to the flexure-shear failure of postfire RC beams. CFRP retrofitted postfire RC beams experienced progressive peeling-off failure. FRP retrofitting significantly increased the yield deflection by 58.2−97.3% but decreased the ultimate deflection by 43.0−55.5% compared with that of the control beam. Consequently, the ductility was reduced by 69.7−74.7%, categorized as low ductility. CFRP retrofitting successfully increased the strengths of 30-min postfire beams by up to 23.1% higher than those of the control beam. Fire significantly decreased the stiffness of postfire beams by 46.4−49.2% compared with that of the control beam, whereas CFRP retrofitting did not fully recover the stiffness of postfire beams. Finally, a simple model of the moment capacity of postfire beams without/with CFRP retrofits was developed based on the practicability of limited data feasibly obtained from real fires. The proposed model, with its simplicity, practicability, and reasonable accuracy, can be a useful tool for structural engineers in the FRP retrofitting of postfire RC structures. Doi: 10.28991/CEJ-2023-09-07-05 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"216 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77433855","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}
Pub Date : 2023-07-01DOI: 10.28991/cej-2023-09-07-06
Arban Berisha
In the last two decades, in the Kosovo area, we have seen extraordinary climate changes and their consequences, such as flash floods, empty reservoirs, and forest burning. So, the objective of this article is to analyze the main drivers of climate change due to global warming, like Temperatures, Precipitation, River flows (TPQ), Human Activity (HA) on one side and the extraterritorial factor of sunspot number NS on the other side. The methodology of the approach is statistical, with trend detection, comparison, and calculation of significance for each factor. There are data in state institutions, daily and monthly, for TPQ from 1963–2022 and Sunspots from 1954–2006. Three Highland HL, two Lowland LL rivers, and two Temperature and Precipitation Meteorological stations were considered for analysis. For river LL1, the data needed to be completed, and correlation, calibration, and validation methods were applied to fill the gaps. Results indicate that sunspot numbers show a decrease of -18% from the average value, Temperature +24%, Precipitation +5%, HL1 flow -31%, HL2 -0.5%, HL3 -7.5%, LL1 -22%, and LL2 -13%. The significance of the impact of Sunspots on the air temperature approximates 75%, while the impact of human activity approximates 25%. This will be an excellent contribution to future water resource management plans. Doi: 10.28991/CEJ-2023-09-07-06 Full Text: PDF
{"title":"Solar and Human Activity Impact on High and Low Land River Flows","authors":"Arban Berisha","doi":"10.28991/cej-2023-09-07-06","DOIUrl":"https://doi.org/10.28991/cej-2023-09-07-06","url":null,"abstract":"In the last two decades, in the Kosovo area, we have seen extraordinary climate changes and their consequences, such as flash floods, empty reservoirs, and forest burning. So, the objective of this article is to analyze the main drivers of climate change due to global warming, like Temperatures, Precipitation, River flows (TPQ), Human Activity (HA) on one side and the extraterritorial factor of sunspot number NS on the other side. The methodology of the approach is statistical, with trend detection, comparison, and calculation of significance for each factor. There are data in state institutions, daily and monthly, for TPQ from 1963–2022 and Sunspots from 1954–2006. Three Highland HL, two Lowland LL rivers, and two Temperature and Precipitation Meteorological stations were considered for analysis. For river LL1, the data needed to be completed, and correlation, calibration, and validation methods were applied to fill the gaps. Results indicate that sunspot numbers show a decrease of -18% from the average value, Temperature +24%, Precipitation +5%, HL1 flow -31%, HL2 -0.5%, HL3 -7.5%, LL1 -22%, and LL2 -13%. The significance of the impact of Sunspots on the air temperature approximates 75%, while the impact of human activity approximates 25%. This will be an excellent contribution to future water resource management plans. Doi: 10.28991/CEJ-2023-09-07-06 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75428189","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}
The objective of this research was to develop a mathematical and statistical model for long-term prediction. The Extreme Value Theory (EVT) was applied to analyze the appropriate distribution model by using the peak-over-threshold approach with Generalized Pareto Distribution (GPD) to predict daily extreme precipitation and extreme temperatures in eight provinces located in the upper northeastern region of Thailand. Generally, each province has only 1–2 meteorological stations, so spatial analysis cannot be performed comprehensively. Therefore, the reanalysis data were obtained from the NOAA Physical Sciences Laboratory. The precipitation data were used for spatial analysis at the level of 25 square kilometers, which comprises 71 grid points, whereas the temperature data were used for spatial analysis at the level of 50 square kilometers, which includes 19 grid points. According to the analysis results, GPD was appropriate for the goodness of fit test with Kolmogorov-Smirnov Statistics (KS Test) according to the estimation for the return level in the annual return periods of 2 years, 5 years, 10 years, 25 years, 50 years, and 100 years, indicating the areas with daily extreme precipitation and extreme temperatures. The analysis results would be useful for supplementing decision-making in planning to cope with risk areas as well as in effective planning for resources and prevention. Doi: 10.28991/CEJ-2023-09-07-014 Full Text: PDF
{"title":"Climate Forecasting Models for Precise Management Using Extreme Value Theory","authors":"Pannarat Guayjarernpanishk, Monchaya Chiangpradit, Butsakorn Kong-ied, Nipaporn Chutiman","doi":"10.28991/cej-2023-09-07-014","DOIUrl":"https://doi.org/10.28991/cej-2023-09-07-014","url":null,"abstract":"The objective of this research was to develop a mathematical and statistical model for long-term prediction. The Extreme Value Theory (EVT) was applied to analyze the appropriate distribution model by using the peak-over-threshold approach with Generalized Pareto Distribution (GPD) to predict daily extreme precipitation and extreme temperatures in eight provinces located in the upper northeastern region of Thailand. Generally, each province has only 1–2 meteorological stations, so spatial analysis cannot be performed comprehensively. Therefore, the reanalysis data were obtained from the NOAA Physical Sciences Laboratory. The precipitation data were used for spatial analysis at the level of 25 square kilometers, which comprises 71 grid points, whereas the temperature data were used for spatial analysis at the level of 50 square kilometers, which includes 19 grid points. According to the analysis results, GPD was appropriate for the goodness of fit test with Kolmogorov-Smirnov Statistics (KS Test) according to the estimation for the return level in the annual return periods of 2 years, 5 years, 10 years, 25 years, 50 years, and 100 years, indicating the areas with daily extreme precipitation and extreme temperatures. The analysis results would be useful for supplementing decision-making in planning to cope with risk areas as well as in effective planning for resources and prevention. Doi: 10.28991/CEJ-2023-09-07-014 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"59 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90054989","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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