Structures known as modular buildings are made in factories and then moved to construction sites, where they are assembled. The efficacy of modular structures under many uncertainties has to be thoroughly investigated as demand rises; fire is one such uncertainty. The purpose of this study is to ascertain how high temperature affects the components of modular constructions. In the current study, hollow steel columns and beams were taken into account as components of a modular construction. Using ABAQUS, several situations were examined depending on the span length to determine the important locations of the members. Experimental research was conducted on the critical regions identified by the analysis, and the results were contrasted with those of the analysis. A high-temperature localized heating furnace was used for the experimental testing. The findings demonstrated that for spans of 250 mm and 500 mm, the central area of the beams was essential, and the load-carrying capacity was six times less than that of heating at the extremities of the beams. Similar to the beams, columns exhibited less fluctuation than the beams and were weaker in the bottom area when exposed to high temperature. When compared to other places, the capacity was reduced by 1.1 times, and in Case 1, the capacity reduction with regard to loading was 1.68 times greater. Doi: 10.28991/CEJ-2024-010-03-014 Full Text: PDF
{"title":"Experimental Study on Hollow Steel Sections Under Elevated Temperature","authors":"Prakash Murugan, Alireza Bahrami, Vishal Murugan, Ajish Kumaran","doi":"10.28991/cej-2024-010-03-014","DOIUrl":"https://doi.org/10.28991/cej-2024-010-03-014","url":null,"abstract":"Structures known as modular buildings are made in factories and then moved to construction sites, where they are assembled. The efficacy of modular structures under many uncertainties has to be thoroughly investigated as demand rises; fire is one such uncertainty. The purpose of this study is to ascertain how high temperature affects the components of modular constructions. In the current study, hollow steel columns and beams were taken into account as components of a modular construction. Using ABAQUS, several situations were examined depending on the span length to determine the important locations of the members. Experimental research was conducted on the critical regions identified by the analysis, and the results were contrasted with those of the analysis. A high-temperature localized heating furnace was used for the experimental testing. The findings demonstrated that for spans of 250 mm and 500 mm, the central area of the beams was essential, and the load-carrying capacity was six times less than that of heating at the extremities of the beams. Similar to the beams, columns exhibited less fluctuation than the beams and were weaker in the bottom area when exposed to high temperature. When compared to other places, the capacity was reduced by 1.1 times, and in Case 1, the capacity reduction with regard to loading was 1.68 times greater. Doi: 10.28991/CEJ-2024-010-03-014 Full Text: PDF","PeriodicalId":10233,"journal":{"name":"Civil Engineering Journal","volume":"138 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140279481","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 : 2024-03-01DOI: 10.28991/cej-2024-010-03-09
B. Kulbayev, Vladimir Lapin, Alexander Shakhnovich, Yeraly Shokbarov, T. Tuleyev, S. Aldakhov, Yerken Aldakhov, Alimzhan Ali
The purpose of the study is an experimental determination of the stress-related characteristics of the structural steel produced in the Republic of Kazakhstan for use in conventional and earthquake-resistive construction. Since 2015, the construction industry has been using European regulatory documents—Eurocodes—as a statutory framework. In particular, the Eurocode 1993 for steel structures and the Eurocode 1998 for the design of earthquake-resistant structures However, the study of stress-related properties of structural steel using experimental methods of ISO standards has not been performed. Therefore, in the construction industry of the Republic of Kazakhstan, steel-work structures have been used in fairly limited volume since 2015. The experimental studies were conducted on 7 types of structural steel with thicknesses of 8, 10, and 20 mm manufactured by Arcelor Mittal. The yield strength, ultimate tensile strength (breaking stress), and tensile strength at break were studied. The experimental studies were carried out on the basis of ISO standards. In each test run, 5 samples were used. In two series, 20 samples each were tested, which made it possible to estimate the yield strength and strength distribution functions. The correlation relationships between Brinell hardness and yield and strength limits have been studied. As a result of experimental studies, it was found that the strength and deformability parameters fully comply with the requirements of Eurocode 1993. Based on the application of the Student's test, it is revealed that the distribution functions of yield strength and resistance correspond to the normal law (Gaussian function). The calculation of a three-story, two-span residential building with box section columns for construction in an area with a seismicity of 8 points is performed by the finite element method. The work results will significantly increase the scope of Kazakhstani structural steel use in seismic and conventional areas of the Republic of Kazakhstan. Doi: 10.28991/CEJ-2024-010-03-09 Full Text: PDF
{"title":"Strength and Deformability of Structural Steel for Use in Construction","authors":"B. Kulbayev, Vladimir Lapin, Alexander Shakhnovich, Yeraly Shokbarov, T. Tuleyev, S. Aldakhov, Yerken Aldakhov, Alimzhan Ali","doi":"10.28991/cej-2024-010-03-09","DOIUrl":"https://doi.org/10.28991/cej-2024-010-03-09","url":null,"abstract":"The purpose of the study is an experimental determination of the stress-related characteristics of the structural steel produced in the Republic of Kazakhstan for use in conventional and earthquake-resistive construction. Since 2015, the construction industry has been using European regulatory documents—Eurocodes—as a statutory framework. In particular, the Eurocode 1993 for steel structures and the Eurocode 1998 for the design of earthquake-resistant structures However, the study of stress-related properties of structural steel using experimental methods of ISO standards has not been performed. Therefore, in the construction industry of the Republic of Kazakhstan, steel-work structures have been used in fairly limited volume since 2015. The experimental studies were conducted on 7 types of structural steel with thicknesses of 8, 10, and 20 mm manufactured by Arcelor Mittal. The yield strength, ultimate tensile strength (breaking stress), and tensile strength at break were studied. The experimental studies were carried out on the basis of ISO standards. In each test run, 5 samples were used. In two series, 20 samples each were tested, which made it possible to estimate the yield strength and strength distribution functions. The correlation relationships between Brinell hardness and yield and strength limits have been studied. As a result of experimental studies, it was found that the strength and deformability parameters fully comply with the requirements of Eurocode 1993. Based on the application of the Student's test, it is revealed that the distribution functions of yield strength and resistance correspond to the normal law (Gaussian function). The calculation of a three-story, two-span residential building with box section columns for construction in an area with a seismicity of 8 points is performed by the finite element method. The work results will significantly increase the scope of Kazakhstani structural steel use in seismic and conventional areas of the Republic of Kazakhstan. Doi: 10.28991/CEJ-2024-010-03-09 Full Text: PDF","PeriodicalId":10233,"journal":{"name":"Civil Engineering Journal","volume":"56 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140271871","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 : 2024-03-01DOI: 10.28991/cej-2024-010-03-02
Anjeza Alaj, Nexhmi Krasniqi, T. Numao
Developing of green construction and reducing CO2emissions in the environment is a priority for industry in the coming years. Recycling fly ash in the concrete industry is a well-known way to reduce environmental impact. Aside from this benefit, there are numerous other positive effects of incorporating fly ash into concrete; however, in this research, the objective is to replace cement with a different percentage of non-class fly ash with high CaO, more than 42%. The analyzed variables are non-class fly ash properties, the effect of fly ash presence on the main properties of concrete and examining the optimum of non-class fly ash in ordinary concrete C-25/30 and high-performance concrete C-50/60. All investigations took place in the laboratory by producing 24 different mix designs and more than 1000 specimens to examine: consistency, setting time, shrinkage, and compressive strength in the short and long terms of curing. Recycling industrial waste in new construction, especially fly ash because of its non-uniform properties, still has some obstacles and is not a practical issue, but the future must be environmentally friendly, and this research proves that the objective of producing sustainable ordinary and high-performance concrete was achieved by replacing 40% of cement with non-class high CaO content fly ash. Doi: 10.28991/CEJ-2024-010-03-02 Full Text: PDF
{"title":"Effect of Non-Class Fly Ash on Strength Properties of Concrete","authors":"Anjeza Alaj, Nexhmi Krasniqi, T. Numao","doi":"10.28991/cej-2024-010-03-02","DOIUrl":"https://doi.org/10.28991/cej-2024-010-03-02","url":null,"abstract":"Developing of green construction and reducing CO2emissions in the environment is a priority for industry in the coming years. Recycling fly ash in the concrete industry is a well-known way to reduce environmental impact. Aside from this benefit, there are numerous other positive effects of incorporating fly ash into concrete; however, in this research, the objective is to replace cement with a different percentage of non-class fly ash with high CaO, more than 42%. The analyzed variables are non-class fly ash properties, the effect of fly ash presence on the main properties of concrete and examining the optimum of non-class fly ash in ordinary concrete C-25/30 and high-performance concrete C-50/60. All investigations took place in the laboratory by producing 24 different mix designs and more than 1000 specimens to examine: consistency, setting time, shrinkage, and compressive strength in the short and long terms of curing. Recycling industrial waste in new construction, especially fly ash because of its non-uniform properties, still has some obstacles and is not a practical issue, but the future must be environmentally friendly, and this research proves that the objective of producing sustainable ordinary and high-performance concrete was achieved by replacing 40% of cement with non-class high CaO content fly ash. Doi: 10.28991/CEJ-2024-010-03-02 Full Text: PDF","PeriodicalId":10233,"journal":{"name":"Civil Engineering Journal","volume":"9 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140272050","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 : 2024-02-01DOI: 10.28991/cej-2024-010-02-05
F. Grajçevci, Armend Mujaj, D. Kryeziu, Elfrida Shehu
This study presents a comparison between numerical and experimental results for reinforced concrete columns subjected to axial compression. Depending on the columns support and their organization within the structure, columns primarily work under either concentric or eccentric compression, respectively, bending in situations where horizontal actions such as wind or/and earthquakes are present in the structure. Different countries have specific design codes, and in this study, the calculation of columns is based on the European design codes, specifically EN 1992-1-1. As a common practice in most cases during research, tests are conducted using computational models, and based on the obtained results through the application of similarity theory, an attempt is made to transition to the actual behavior of structural elements. Therefore, this paper applies a logic of "almost real" testing, where two columns with square cross-sections were produced and tested. The columns had a rectangular base with cross-section dimensions of 20/20 cm and a height (L) of 300 cm, with a concrete strength of fcm,cube=61.80 MPa. They were reinforced with longitudinal reinforcement (4Ø12 mm) and had a tensile strength of ftm=588.10 MPa. Additionally, stirrups of Ø8 mm were placed at every sw=25 cm. Experimental results show a closer alignment with software calculations using SEISMOSOFT with an accuracy of 96%, while results according to EN 1992-1-1, based on simplified methods, show 64% for the Nominal Stiffness Method and 59% for the Curvature Method. Doi: 10.28991/CEJ-2024-010-02-05 Full Text: PDF
{"title":"Experimental and Numerical Analysis of Concrete Columns under Axial Load Based on European Design Norms","authors":"F. Grajçevci, Armend Mujaj, D. Kryeziu, Elfrida Shehu","doi":"10.28991/cej-2024-010-02-05","DOIUrl":"https://doi.org/10.28991/cej-2024-010-02-05","url":null,"abstract":"This study presents a comparison between numerical and experimental results for reinforced concrete columns subjected to axial compression. Depending on the columns support and their organization within the structure, columns primarily work under either concentric or eccentric compression, respectively, bending in situations where horizontal actions such as wind or/and earthquakes are present in the structure. Different countries have specific design codes, and in this study, the calculation of columns is based on the European design codes, specifically EN 1992-1-1. As a common practice in most cases during research, tests are conducted using computational models, and based on the obtained results through the application of similarity theory, an attempt is made to transition to the actual behavior of structural elements. Therefore, this paper applies a logic of \"almost real\" testing, where two columns with square cross-sections were produced and tested. The columns had a rectangular base with cross-section dimensions of 20/20 cm and a height (L) of 300 cm, with a concrete strength of fcm,cube=61.80 MPa. They were reinforced with longitudinal reinforcement (4Ø12 mm) and had a tensile strength of ftm=588.10 MPa. Additionally, stirrups of Ø8 mm were placed at every sw=25 cm. Experimental results show a closer alignment with software calculations using SEISMOSOFT with an accuracy of 96%, while results according to EN 1992-1-1, based on simplified methods, show 64% for the Nominal Stiffness Method and 59% for the Curvature Method. Doi: 10.28991/CEJ-2024-010-02-05 Full Text: PDF","PeriodicalId":10233,"journal":{"name":"Civil Engineering Journal","volume":"300 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140468352","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 : 2024-02-01DOI: 10.28991/cej-2024-010-02-016
Fadoua Hattani, Bruce Menu, D. Allaoui, Mustapha Mouflih, Hassan Zanzoun, Hassan Hannache, Bouchaib Manoun
This paper aims to evaluate the influence of sand quality, water-to-cement ratio, binder properties, mix design methods, and mixing techniques on the fresh and hardened properties of concrete. The physicochemical characteristics of coarse aggregates, sands, and binders were analyzed. The experimental results show that the binders and coarse aggregates met standard specifications. However, none of the sands meet construction standards. Corrections were necessary for the dune sands to meet construction standards in terms of grain size distribution and fineness modulus. The results also show that the concretes formulated using the Dreux-Gorisse method exhibited higher quality than the locally formulated concretes. Furthermore, it was found that hand mixing resulted in inadequate mixing, material wastage, lower strength, and increased porosity, whereas machine mixing produced concretes with a more homogeneous microstructure, uniform particle distribution, lower porosity, and higher strength. The batch variability and compressive strength of the hand-mixed concretes were also found to be influenced by the expertise level of the batch mixer and the number of successive hand batches. It was also found that both the soluble silica and the inert methods are reliable for determining binder content in machine-mixed concrete. However, the soluble silica method occasionally exhibited significant variations in hand-mixed concrete compared to the inert method. A combined approach utilizing the average of both methods enhances the overall reliability of the binder content values. Observations on construction sites revealed widespread deviations from recommended guidelines. Issues such as lack of material inspection, proper stockpiling, ingredient contamination, and inadequate batch mixing contributed to variations in concrete workability, porosity, and compressive strength. Doi: 10.28991/CEJ-2024-010-02-016 Full Text: PDF
{"title":"Evaluating the Impact of Material Selections, Mixing Techniques, and On-site Practices on Performance of Concrete Mixtures","authors":"Fadoua Hattani, Bruce Menu, D. Allaoui, Mustapha Mouflih, Hassan Zanzoun, Hassan Hannache, Bouchaib Manoun","doi":"10.28991/cej-2024-010-02-016","DOIUrl":"https://doi.org/10.28991/cej-2024-010-02-016","url":null,"abstract":"This paper aims to evaluate the influence of sand quality, water-to-cement ratio, binder properties, mix design methods, and mixing techniques on the fresh and hardened properties of concrete. The physicochemical characteristics of coarse aggregates, sands, and binders were analyzed. The experimental results show that the binders and coarse aggregates met standard specifications. However, none of the sands meet construction standards. Corrections were necessary for the dune sands to meet construction standards in terms of grain size distribution and fineness modulus. The results also show that the concretes formulated using the Dreux-Gorisse method exhibited higher quality than the locally formulated concretes. Furthermore, it was found that hand mixing resulted in inadequate mixing, material wastage, lower strength, and increased porosity, whereas machine mixing produced concretes with a more homogeneous microstructure, uniform particle distribution, lower porosity, and higher strength. The batch variability and compressive strength of the hand-mixed concretes were also found to be influenced by the expertise level of the batch mixer and the number of successive hand batches. It was also found that both the soluble silica and the inert methods are reliable for determining binder content in machine-mixed concrete. However, the soluble silica method occasionally exhibited significant variations in hand-mixed concrete compared to the inert method. A combined approach utilizing the average of both methods enhances the overall reliability of the binder content values. Observations on construction sites revealed widespread deviations from recommended guidelines. Issues such as lack of material inspection, proper stockpiling, ingredient contamination, and inadequate batch mixing contributed to variations in concrete workability, porosity, and compressive strength. Doi: 10.28991/CEJ-2024-010-02-016 Full Text: PDF","PeriodicalId":10233,"journal":{"name":"Civil Engineering Journal","volume":"229 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140468644","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 : 2024-02-01DOI: 10.28991/cej-2024-010-02-018
Arief A. Soebroto, L. Limantara, E. Suhartanto, Moh. Sholichin
Early warning of flood hazards needs to be carried out comprehensively to avoid a higher risk of disaster. Every decision on early warning of a flood hazard is carried out in part by one party, namely the government or water resource managers. This research aims to provide a collaborative decision-making model for early warning of flood hazards through a Group Decision Support System Model (GDSS), especially in Indonesia. The novelty of this research is that the GDSS model involves more than one decision-maker and multi-criteria decision-making for early warning of flood hazards in the downstream Kali Sadar River, Mojokerto Regency, East Java Province, Indonesia. The GDSS model was developed using a hybrid method, namely the Analytical Network Process (ANP) and VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR). There was more than one decision result; voting was carried out using the BORDA method to produce the decision. The test results of GDSS were obtained using a Spearman rank correlation coefficient of 0.8425 and matrix confusion, an accuracy value of 86.7%, a precision value of 86.7%, a recall value of 86.7%, and an f-measure of 86.7%. Based on the test results, good results were obtained from the GDSS model. Doi: 10.28991/CEJ-2024-010-02-018 Full Text: PDF
{"title":"Modelling of Flood Hazard Early Warning Group Decision Support System","authors":"Arief A. Soebroto, L. Limantara, E. Suhartanto, Moh. Sholichin","doi":"10.28991/cej-2024-010-02-018","DOIUrl":"https://doi.org/10.28991/cej-2024-010-02-018","url":null,"abstract":"Early warning of flood hazards needs to be carried out comprehensively to avoid a higher risk of disaster. Every decision on early warning of a flood hazard is carried out in part by one party, namely the government or water resource managers. This research aims to provide a collaborative decision-making model for early warning of flood hazards through a Group Decision Support System Model (GDSS), especially in Indonesia. The novelty of this research is that the GDSS model involves more than one decision-maker and multi-criteria decision-making for early warning of flood hazards in the downstream Kali Sadar River, Mojokerto Regency, East Java Province, Indonesia. The GDSS model was developed using a hybrid method, namely the Analytical Network Process (ANP) and VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR). There was more than one decision result; voting was carried out using the BORDA method to produce the decision. The test results of GDSS were obtained using a Spearman rank correlation coefficient of 0.8425 and matrix confusion, an accuracy value of 86.7%, a precision value of 86.7%, a recall value of 86.7%, and an f-measure of 86.7%. Based on the test results, good results were obtained from the GDSS model. Doi: 10.28991/CEJ-2024-010-02-018 Full Text: PDF","PeriodicalId":10233,"journal":{"name":"Civil Engineering Journal","volume":"1159 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140467269","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 : 2024-02-01DOI: 10.28991/cej-2024-010-02-017
Ahlam A. Abbood, Nazar Oukaili
The paper presents a novel method of reinforcing concrete columns using small-diameter steel tubes instead of traditional steel bars. The researchers conducted experimental investigations on twelve mid-scale circular concrete column specimens, which were divided into two groups consisting of six specimens each: short and long columns. Two of the specimens in each group were reinforced with steel bars, while the remaining four were reinforced with steel tubes filled with cementitious grouting material. The study proposed two concepts for cementitious grouted steel-tube reinforcement. The first concept utilized steel tubes with equivalent net areas to the steel bar areas used in the reference column, while the second concept used steel-tube reinforcement with the same diameter as the steel bars in the reference column. Nonlinear Finite Element (FE) analyses were conducted on experimental specimens using ABAQUS software. The results showed that using steel tubes with an area equivalent to that of steel bars instead of conventional columns increased the bearing capacity of reinforced concrete columns by 17%. Moreover, using steel tubes whose area matched 30% of the steel bar area achieved a bearing capacity of about 81% of the conventional concrete columns. The experimental and FE analysis findings indicate that this methodology can increase the bearing capacity of reinforced concrete columns when compared to traditional methods. The axial load-axial displacement curves, axial load-axial strain curves, and failure load of the FE model all demonstrated good convergence with the experimental data. Doi: 10.28991/CEJ-2024-010-02-017 Full Text: PDF
{"title":"Behavior of Axially Loaded Concrete Columns Reinforced with Steel Tubes Infilled with Cementitious Grouting Material","authors":"Ahlam A. Abbood, Nazar Oukaili","doi":"10.28991/cej-2024-010-02-017","DOIUrl":"https://doi.org/10.28991/cej-2024-010-02-017","url":null,"abstract":"The paper presents a novel method of reinforcing concrete columns using small-diameter steel tubes instead of traditional steel bars. The researchers conducted experimental investigations on twelve mid-scale circular concrete column specimens, which were divided into two groups consisting of six specimens each: short and long columns. Two of the specimens in each group were reinforced with steel bars, while the remaining four were reinforced with steel tubes filled with cementitious grouting material. The study proposed two concepts for cementitious grouted steel-tube reinforcement. The first concept utilized steel tubes with equivalent net areas to the steel bar areas used in the reference column, while the second concept used steel-tube reinforcement with the same diameter as the steel bars in the reference column. Nonlinear Finite Element (FE) analyses were conducted on experimental specimens using ABAQUS software. The results showed that using steel tubes with an area equivalent to that of steel bars instead of conventional columns increased the bearing capacity of reinforced concrete columns by 17%. Moreover, using steel tubes whose area matched 30% of the steel bar area achieved a bearing capacity of about 81% of the conventional concrete columns. The experimental and FE analysis findings indicate that this methodology can increase the bearing capacity of reinforced concrete columns when compared to traditional methods. The axial load-axial displacement curves, axial load-axial strain curves, and failure load of the FE model all demonstrated good convergence with the experimental data. Doi: 10.28991/CEJ-2024-010-02-017 Full Text: PDF","PeriodicalId":10233,"journal":{"name":"Civil Engineering Journal","volume":"10 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140468042","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 : 2024-02-01DOI: 10.28991/cej-2024-010-02-04
N. Muhaisen, T. Khayyun, Mustafa Al-Mukhtar
A two-dimensional operation chart is commonly used to manage the operation of a dual-reservoir system, where the water storage in each reservoir is accurately considered in the water-supply decision. The dual reservoir chart should be combined with one allocation rule to better represent water supply distribution between reservoirs. In this study, the 2D rule curve was coupled with three allocation rules: variable allocation ratios, fixed allocation ratios, and compensation regulation, to identify the efficiency of using these rules with the 2D rule curve in operating the dual reservoirs. Mosul-Dukan dual reservoirs in Iraq were implemented as a study area using monthly data extended from 2001 to 2020. The Shuffled Complex Evolution Algorithm was used to optimize the water allocation ratios. The results revealed that the variable allocation ratios were superior to the other two rules in terms of water deficit, in which the total water shortage of the variable allocation ratios rule was 56590 Mm3. The total shortage was less than that obtained by the fixed allocation ratio and compensation regulation rules by 0.9% and 56%, respectively. Finally, the variable allocation ratio was more suitable for application with a 2D reservoir rule curve than the two remaining rules (fixed allocation ratio and compensation regulation rules). The variable allocation ratios sustainably manage reservoirs in the regions that suffer from water scarcity and represent the most vulnerable to the impact of climate change. Doi: 10.28991/CEJ-2024-010-02-04 Full Text: PDF
{"title":"Optimization of Dualistic Reservoir System Two-Dimensional Rule Curve with Three Allocation Rules","authors":"N. Muhaisen, T. Khayyun, Mustafa Al-Mukhtar","doi":"10.28991/cej-2024-010-02-04","DOIUrl":"https://doi.org/10.28991/cej-2024-010-02-04","url":null,"abstract":"A two-dimensional operation chart is commonly used to manage the operation of a dual-reservoir system, where the water storage in each reservoir is accurately considered in the water-supply decision. The dual reservoir chart should be combined with one allocation rule to better represent water supply distribution between reservoirs. In this study, the 2D rule curve was coupled with three allocation rules: variable allocation ratios, fixed allocation ratios, and compensation regulation, to identify the efficiency of using these rules with the 2D rule curve in operating the dual reservoirs. Mosul-Dukan dual reservoirs in Iraq were implemented as a study area using monthly data extended from 2001 to 2020. The Shuffled Complex Evolution Algorithm was used to optimize the water allocation ratios. The results revealed that the variable allocation ratios were superior to the other two rules in terms of water deficit, in which the total water shortage of the variable allocation ratios rule was 56590 Mm3. The total shortage was less than that obtained by the fixed allocation ratio and compensation regulation rules by 0.9% and 56%, respectively. Finally, the variable allocation ratio was more suitable for application with a 2D reservoir rule curve than the two remaining rules (fixed allocation ratio and compensation regulation rules). The variable allocation ratios sustainably manage reservoirs in the regions that suffer from water scarcity and represent the most vulnerable to the impact of climate change. Doi: 10.28991/CEJ-2024-010-02-04 Full Text: PDF","PeriodicalId":10233,"journal":{"name":"Civil Engineering Journal","volume":"69 13","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140463136","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 : 2024-02-01DOI: 10.28991/cej-2024-010-02-08
Petar Praštalo, Mato Uljarević, R. Vukomanovic
Understanding the failure mechanisms of embankment dams due to overtopping is vital for flood protection, covering planning, design, and flood defence zone management. Typically, dam failure-induced flood wave propagation is modeled in 1D using Saint-Venant's equations. The breach itself is often simplified as a trapezoid defined by its final height, average width, side slopes, and the time required for complete formation. Often overlooked is the dynamic process of breach formation and its correlation with the outflow hydrograph during dam failure. This research scrutinizes the impact of breach parameters and progression curves on the outflow hydrograph. Two approaches were formulated: one crafting new equations for average breach width and formation time using global dam failure data and regression analysis, and the other employing these equations in 2D HEC-RAS dam failure modeling, comparing them with literature recommendations. The derived equations yield results similar to those in the literature. This study introduces a novel aspect by examining the mutual influence of results and floodplain areas on the outflow hydrograph, offering a comprehensive perspective on dam failure dynamics and its hydraulic consequences. Doi: 10.28991/CEJ-2024-010-02-08 Full Text: PDF
{"title":"Effect of Breach Parameters and Progression Curves on Dam Failure Hydrograph","authors":"Petar Praštalo, Mato Uljarević, R. Vukomanovic","doi":"10.28991/cej-2024-010-02-08","DOIUrl":"https://doi.org/10.28991/cej-2024-010-02-08","url":null,"abstract":"Understanding the failure mechanisms of embankment dams due to overtopping is vital for flood protection, covering planning, design, and flood defence zone management. Typically, dam failure-induced flood wave propagation is modeled in 1D using Saint-Venant's equations. The breach itself is often simplified as a trapezoid defined by its final height, average width, side slopes, and the time required for complete formation. Often overlooked is the dynamic process of breach formation and its correlation with the outflow hydrograph during dam failure. This research scrutinizes the impact of breach parameters and progression curves on the outflow hydrograph. Two approaches were formulated: one crafting new equations for average breach width and formation time using global dam failure data and regression analysis, and the other employing these equations in 2D HEC-RAS dam failure modeling, comparing them with literature recommendations. The derived equations yield results similar to those in the literature. This study introduces a novel aspect by examining the mutual influence of results and floodplain areas on the outflow hydrograph, offering a comprehensive perspective on dam failure dynamics and its hydraulic consequences. Doi: 10.28991/CEJ-2024-010-02-08 Full Text: PDF","PeriodicalId":10233,"journal":{"name":"Civil Engineering Journal","volume":"1050 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140467340","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 : 2024-02-01DOI: 10.28991/cej-2024-010-02-011
Musa AbdulMuttalib Issa, A. Allawi, Nazar Oukaili
This study investigates the impact of varying glass fiber-reinforced polymer (GFRP) stirrup spacing on the performance of doubly GFRP-reinforced concrete beams. The research focuses on assessing the behavior of GFRP-reinforced concrete beams, including load-carrying capacity, cracking, and deformability. It explores the feasibility and effectiveness of GFRP bars as an alternative to traditional steel reinforcement in concrete structures. Six concrete beams with a cross-section of 300 mm (wide) × 250 mm (deep), simply supported on a 2100 mm span, were tested. The beams underwent four-point bending with two concentrated loads applied symmetrically at one-third of the span length, resulting in a shear span (a)-to-depth (h) ratio of 2.8. The experimental findings reveal that altering the GFRP stirrup spacing along the longitudinal axis of the beams, from 200 mm (equivalent to the effective depth (d)) to 50 mm (equal to (d⁄4)), altered the mode of failure from flexure-shear to flexure-compression. However, when the spacing was equal to or less than (d⁄3), there was no significant improvement in load-carrying capacity, as the contribution of GFRP bars in resisting shear loads was limited. Under service loads, the GFRP-reinforced beams exhibited wider cracks, but reducing the stirrup spacing helped restrain crack widening. Incorporating GFRP bars in the compression zone had a positive effect on reducing crack width in the tension zone. Additionally, using GFRP stirrups with spacing varying between (d) and (d⁄2) in the pure bending region increased the deflection ductility indexes. To enhance the ductility of GFRP-reinforced concrete beams, it is recommended to use GFRP stirrups in the pure bending region with spacing greater than the spacing between GFRP stirrups in the shear spans. The study highlights that the current ACI code overestimates the shear capacity provided by GFRP stirrups, particularly when the spacing is less than or equal to (d⁄3). Doi: 10.28991/CEJ-2024-010-02-011 Full Text: PDF
{"title":"Effects of GFRP Stirrup Spacing on the Behavior of Doubly GFRP-Reinforced Concrete Beams","authors":"Musa AbdulMuttalib Issa, A. Allawi, Nazar Oukaili","doi":"10.28991/cej-2024-010-02-011","DOIUrl":"https://doi.org/10.28991/cej-2024-010-02-011","url":null,"abstract":"This study investigates the impact of varying glass fiber-reinforced polymer (GFRP) stirrup spacing on the performance of doubly GFRP-reinforced concrete beams. The research focuses on assessing the behavior of GFRP-reinforced concrete beams, including load-carrying capacity, cracking, and deformability. It explores the feasibility and effectiveness of GFRP bars as an alternative to traditional steel reinforcement in concrete structures. Six concrete beams with a cross-section of 300 mm (wide) × 250 mm (deep), simply supported on a 2100 mm span, were tested. The beams underwent four-point bending with two concentrated loads applied symmetrically at one-third of the span length, resulting in a shear span (a)-to-depth (h) ratio of 2.8. The experimental findings reveal that altering the GFRP stirrup spacing along the longitudinal axis of the beams, from 200 mm (equivalent to the effective depth (d)) to 50 mm (equal to (d⁄4)), altered the mode of failure from flexure-shear to flexure-compression. However, when the spacing was equal to or less than (d⁄3), there was no significant improvement in load-carrying capacity, as the contribution of GFRP bars in resisting shear loads was limited. Under service loads, the GFRP-reinforced beams exhibited wider cracks, but reducing the stirrup spacing helped restrain crack widening. Incorporating GFRP bars in the compression zone had a positive effect on reducing crack width in the tension zone. Additionally, using GFRP stirrups with spacing varying between (d) and (d⁄2) in the pure bending region increased the deflection ductility indexes. To enhance the ductility of GFRP-reinforced concrete beams, it is recommended to use GFRP stirrups in the pure bending region with spacing greater than the spacing between GFRP stirrups in the shear spans. The study highlights that the current ACI code overestimates the shear capacity provided by GFRP stirrups, particularly when the spacing is less than or equal to (d⁄3). Doi: 10.28991/CEJ-2024-010-02-011 Full Text: PDF","PeriodicalId":10233,"journal":{"name":"Civil Engineering Journal","volume":"127 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140470452","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：