Pub Date : 2023-06-01DOI: 10.28991/cej-2023-09-06-06
Yassine Razzouk, Mohamed Ahatri, K. Baba, Ahlam El Majid
This study aims to investigate the impact of soil-structure interaction (SSI) on the seismic behavior of reinforced concrete buildings. An advanced numerical model for SSI was developed and verified using ABAQUS software. The seismic response of a 12-story building on four types of soil (rock, dense soil, stiff soil, and soft soil) was examined using a Normalized Response Spectra based on the Moroccan paraseismic regulation RPS 2011. The global lateral displacement, inter-story drift, and period were compared for two types of bracing (column and shear wall). The results show that SSI has a significant impact on the seismic behavior of buildings, and the seismic responses of soil-structure systems with column and shear wall bracing are quite different. The research contributions of this paper include developing an advanced numerical model for SSI, examining the impact of SSI on the choice of bracing for reinforced concrete buildings, and providing guidance on the most reliable bracing method for structures of various heights and soil types. The study's findings have important implications for seismic design and can help improve the safety and reliability of buildings in earthquake-prone regions. The study also highlights the importance of considering SSI in seismic design and the need for guidelines that describe the bracing systems to be used based on the structure's height and type of soil. Doi: 10.28991/CEJ-2023-09-06-06 Full Text: PDF
{"title":"Optimal Bracing Type of Reinforced Concrete Buildings with Soil-Structure Interaction Taken into Consideration","authors":"Yassine Razzouk, Mohamed Ahatri, K. Baba, Ahlam El Majid","doi":"10.28991/cej-2023-09-06-06","DOIUrl":"https://doi.org/10.28991/cej-2023-09-06-06","url":null,"abstract":"This study aims to investigate the impact of soil-structure interaction (SSI) on the seismic behavior of reinforced concrete buildings. An advanced numerical model for SSI was developed and verified using ABAQUS software. The seismic response of a 12-story building on four types of soil (rock, dense soil, stiff soil, and soft soil) was examined using a Normalized Response Spectra based on the Moroccan paraseismic regulation RPS 2011. The global lateral displacement, inter-story drift, and period were compared for two types of bracing (column and shear wall). The results show that SSI has a significant impact on the seismic behavior of buildings, and the seismic responses of soil-structure systems with column and shear wall bracing are quite different. The research contributions of this paper include developing an advanced numerical model for SSI, examining the impact of SSI on the choice of bracing for reinforced concrete buildings, and providing guidance on the most reliable bracing method for structures of various heights and soil types. The study's findings have important implications for seismic design and can help improve the safety and reliability of buildings in earthquake-prone regions. The study also highlights the importance of considering SSI in seismic design and the need for guidelines that describe the bracing systems to be used based on the structure's height and type of soil. Doi: 10.28991/CEJ-2023-09-06-06 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"67 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86080430","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 : 2023-06-01DOI: 10.28991/cej-2023-09-06-03
Rokhaya Gueye, Makhaly Bâ, I. Mbaye, Ida Bibalo Josiane Ki
One of the main hydraulic properties of unsaturated soils is the Soil-Water Characteristic Curve (SWCC). It is essential to understand, predict soil water storage and determine the hydraulic and mechanical behaviour of soils. These curves can be obtained by direct and indirect measurements. The measurements to obtain these curves are expensive, delicate to perform and can be really slow for fine soils, so predictive models become necessary. In order to make a numerical model, a couple of identification tests were carried out to obtain the physical properties of each sample among the four subgrade materials collected in the regions of Dakar and Thies (Senegal). The measurement tests of the matric suction were then conducted depending on the nature of the material (fine-grained soil or coarse-grained soil) and allowed to draw the SWCC of each soil. Among numerous predictive models developed for SWCC in the last decades; this study used the Perera model to fit the SWCC of four (04) subgrade materials, which did not give a satisfactory coefficient of correlation (R2 = 58% and a relatively low sum of the squared residuals (SSR)). This leads to modifying the Perera model to better fit the SWCC on the basis of an understanding of the effect of each parameter on the shape of the SWCC. The proposed modified model was validated by checking the adjusted R2, minimizing the SSR in order to approach at most the experimental air entry value. The modified model works pretty well on coarse-grained and fine-grained soils. This modified model of Perera provided a very good correlation R2equal to 99.98, 98.74, 99.64, and 99.73 for the sandy soils (Sebikotane and Keur Mory) and the Marley and Clayey soils of Diamniadio, with a minimal SSR obtained compared to Perera’s and Hernandez model. Doi: 10.28991/CEJ-2023-09-06-03 Full Text: PDF
{"title":"Prediction of Soil-Water Characteristic Curves of Four Subgrade Materials using a Modified Perera Model","authors":"Rokhaya Gueye, Makhaly Bâ, I. Mbaye, Ida Bibalo Josiane Ki","doi":"10.28991/cej-2023-09-06-03","DOIUrl":"https://doi.org/10.28991/cej-2023-09-06-03","url":null,"abstract":"One of the main hydraulic properties of unsaturated soils is the Soil-Water Characteristic Curve (SWCC). It is essential to understand, predict soil water storage and determine the hydraulic and mechanical behaviour of soils. These curves can be obtained by direct and indirect measurements. The measurements to obtain these curves are expensive, delicate to perform and can be really slow for fine soils, so predictive models become necessary. In order to make a numerical model, a couple of identification tests were carried out to obtain the physical properties of each sample among the four subgrade materials collected in the regions of Dakar and Thies (Senegal). The measurement tests of the matric suction were then conducted depending on the nature of the material (fine-grained soil or coarse-grained soil) and allowed to draw the SWCC of each soil. Among numerous predictive models developed for SWCC in the last decades; this study used the Perera model to fit the SWCC of four (04) subgrade materials, which did not give a satisfactory coefficient of correlation (R2 = 58% and a relatively low sum of the squared residuals (SSR)). This leads to modifying the Perera model to better fit the SWCC on the basis of an understanding of the effect of each parameter on the shape of the SWCC. The proposed modified model was validated by checking the adjusted R2, minimizing the SSR in order to approach at most the experimental air entry value. The modified model works pretty well on coarse-grained and fine-grained soils. This modified model of Perera provided a very good correlation R2equal to 99.98, 98.74, 99.64, and 99.73 for the sandy soils (Sebikotane and Keur Mory) and the Marley and Clayey soils of Diamniadio, with a minimal SSR obtained compared to Perera’s and Hernandez model. Doi: 10.28991/CEJ-2023-09-06-03 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87328345","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 : 2023-06-01DOI: 10.28991/cej-2023-09-06-013
Gia Thanh Nguyen, Trinh Thi Kieu Lam, N. Huynh
Reusing and recycling laptops has many positive benefits, both environmentally and economically. Therefore, this study was conducted with the objectives of assessing (1) the current state of ownership, (2) the current state of use and disposal, and (3) quantifying the potential reuse and recycling of laptops for students at Can Tho University, Vietnam. Based on data collected by document review and face-to-face interviews with students, with a usage rate of 1 laptop per student, it is estimated that the whole of Can Tho University has 42,918 laptops in use. The actual use lifespan of the laptop is 5.28 years, lower than the expected lifespan of 6.8 years. The results of the correlation analysis show that the actual usage life does not have any correlation with the consumption behavior of students. In addition, the study estimates that 96.67% of laptops will be disposed of before 2031. In which, the potential for direct reuse is 2.33%, reuse with support is 88.33%, and recycling is 9.33%. The results show that universities have great potential to implement safe e-waste collection and treatment activities. Doi: 10.28991/CEJ-2023-09-06-013 Full Text: PDF
{"title":"Assessment of E-Waste Management and Potential for Laptop Reuse and Recycling","authors":"Gia Thanh Nguyen, Trinh Thi Kieu Lam, N. Huynh","doi":"10.28991/cej-2023-09-06-013","DOIUrl":"https://doi.org/10.28991/cej-2023-09-06-013","url":null,"abstract":"Reusing and recycling laptops has many positive benefits, both environmentally and economically. Therefore, this study was conducted with the objectives of assessing (1) the current state of ownership, (2) the current state of use and disposal, and (3) quantifying the potential reuse and recycling of laptops for students at Can Tho University, Vietnam. Based on data collected by document review and face-to-face interviews with students, with a usage rate of 1 laptop per student, it is estimated that the whole of Can Tho University has 42,918 laptops in use. The actual use lifespan of the laptop is 5.28 years, lower than the expected lifespan of 6.8 years. The results of the correlation analysis show that the actual usage life does not have any correlation with the consumption behavior of students. In addition, the study estimates that 96.67% of laptops will be disposed of before 2031. In which, the potential for direct reuse is 2.33%, reuse with support is 88.33%, and recycling is 9.33%. The results show that universities have great potential to implement safe e-waste collection and treatment activities. Doi: 10.28991/CEJ-2023-09-06-013 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"90 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80471683","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 : 2023-06-01DOI: 10.28991/cej-2023-09-06-010
M. S. Shubber, T. Mohammed, K. M. Breesem
Concrete is a material that is strong in compression but weak in tension. To overcome this issue, reinforcement must be used to improve the tensile strength of the concrete. However, it is acknowledged that steel has its drawbacks, such as the fact that it has a high cost and corrosion potential, and the rebar is heavy, non-renewable, and non-environmentally friendly. Thus, this experimental study investigates the potential product of economical reinforced concrete slabs using eco-friendly materials. Firstly, to enhance the concrete properties, a compressive, tensile, and flexural test, also a concrete with the addition of polypropylene fiber outlasted the control mix design in terms of strength and durability. The results included the control mix (CM), F1 0.25%, F2 0.50%, F3 0.75%, and F4 1%. The specimen with the highest compression and tensile strength was 24.28 MPa and 3.15 MPa, respectively, for the F1 specimen with 0.25% short fibers. Secondly, the bending test was carried out on ten slabs to check the structural behavior of these slabs reinforced with reed rods as the eco-friendly material. The good results of the bearing capacity of a partially reinforced concrete slab with a reed have been obtained at 23.8 kN. Meanwhile, to obtain better results, this research has enhanced the behavior of the concrete slab by improving the concrete's properties by adding polypropylene synthetic microfiber to the mixed concrete. In addition, giant reeds treated with epoxy increase the bonding strength with concrete, improve tensile strength properties, and reduce the absorption of reeds. Therefore, the bearing capacity results of the reed-reinforced concrete slab became the best, which were 35.83 kN. Thus, reinforcement of one-way slabs by reed partially with appropriate diameters could be substituted to obtain good performance in the reconstruction of low-cost buildings. As a result, economical reinforced concrete slabs have been produced using eco-friendly materials. Doi: 10.28991/CEJ-2023-09-06-010 Full Text: PDF
{"title":"Production Economical Reinforced Concrete Slabs using Eco-Friendly Material","authors":"M. S. Shubber, T. Mohammed, K. M. Breesem","doi":"10.28991/cej-2023-09-06-010","DOIUrl":"https://doi.org/10.28991/cej-2023-09-06-010","url":null,"abstract":"Concrete is a material that is strong in compression but weak in tension. To overcome this issue, reinforcement must be used to improve the tensile strength of the concrete. However, it is acknowledged that steel has its drawbacks, such as the fact that it has a high cost and corrosion potential, and the rebar is heavy, non-renewable, and non-environmentally friendly. Thus, this experimental study investigates the potential product of economical reinforced concrete slabs using eco-friendly materials. Firstly, to enhance the concrete properties, a compressive, tensile, and flexural test, also a concrete with the addition of polypropylene fiber outlasted the control mix design in terms of strength and durability. The results included the control mix (CM), F1 0.25%, F2 0.50%, F3 0.75%, and F4 1%. The specimen with the highest compression and tensile strength was 24.28 MPa and 3.15 MPa, respectively, for the F1 specimen with 0.25% short fibers. Secondly, the bending test was carried out on ten slabs to check the structural behavior of these slabs reinforced with reed rods as the eco-friendly material. The good results of the bearing capacity of a partially reinforced concrete slab with a reed have been obtained at 23.8 kN. Meanwhile, to obtain better results, this research has enhanced the behavior of the concrete slab by improving the concrete's properties by adding polypropylene synthetic microfiber to the mixed concrete. In addition, giant reeds treated with epoxy increase the bonding strength with concrete, improve tensile strength properties, and reduce the absorption of reeds. Therefore, the bearing capacity results of the reed-reinforced concrete slab became the best, which were 35.83 kN. Thus, reinforcement of one-way slabs by reed partially with appropriate diameters could be substituted to obtain good performance in the reconstruction of low-cost buildings. As a result, economical reinforced concrete slabs have been produced using eco-friendly materials. Doi: 10.28991/CEJ-2023-09-06-010 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76704262","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 : 2023-06-01DOI: 10.28991/cej-2023-09-06-015
E. Pakhomova, S. Emelyanov, Viktor Yartsev, V. Danilov, P. Monastyrev
The purpose of this work is to experimentally determine the climatic effects on the performance of wood-based panels using the methodology developed on the basis of the thermo-fluctuation concept of material aging. This methodology makes it possible to determine the durability of the material by taking into account the simultaneous action of temperature, time, and mechanical stress, as well as additional external influences. The experiments were conducted on particleboard, fiberboard, and plywood. The following climatic effects were studied experimentally in specialized laboratory facilities: high humidity, thermal aging, and UV-irradiation. As the evaluation indicators of the performance characteristics of wood boards were selected, water absorption, swelling rate, thermal expansion, penetration strength, and bending strength. From a theoretical point of view, the value of this work lies in demonstrating a methodology for determining the performance characteristics of particleboard, fiberboard, and plywood, which is highly accurate by considering these characteristics together rather than separately. From a practical point of view, this paper contains experimental results that allow us to judge the characteristics of the wood boards. It has been proven that exposure to UV rays and heat aging causes the binder between the filler particles to break down, and moisture is detrimental to the filler. The thermo-fluctuational constants obtained in the course of the study make it possible to predict the durability of the materials in question over a large range of operating parameters. Doi: 10.28991/CEJ-2023-09-06-015 Full Text: PDF
{"title":"The Influence of Climatic Aging on the Performance of Wood-Based Panels","authors":"E. Pakhomova, S. Emelyanov, Viktor Yartsev, V. Danilov, P. Monastyrev","doi":"10.28991/cej-2023-09-06-015","DOIUrl":"https://doi.org/10.28991/cej-2023-09-06-015","url":null,"abstract":"The purpose of this work is to experimentally determine the climatic effects on the performance of wood-based panels using the methodology developed on the basis of the thermo-fluctuation concept of material aging. This methodology makes it possible to determine the durability of the material by taking into account the simultaneous action of temperature, time, and mechanical stress, as well as additional external influences. The experiments were conducted on particleboard, fiberboard, and plywood. The following climatic effects were studied experimentally in specialized laboratory facilities: high humidity, thermal aging, and UV-irradiation. As the evaluation indicators of the performance characteristics of wood boards were selected, water absorption, swelling rate, thermal expansion, penetration strength, and bending strength. From a theoretical point of view, the value of this work lies in demonstrating a methodology for determining the performance characteristics of particleboard, fiberboard, and plywood, which is highly accurate by considering these characteristics together rather than separately. From a practical point of view, this paper contains experimental results that allow us to judge the characteristics of the wood boards. It has been proven that exposure to UV rays and heat aging causes the binder between the filler particles to break down, and moisture is detrimental to the filler. The thermo-fluctuational constants obtained in the course of the study make it possible to predict the durability of the materials in question over a large range of operating parameters. Doi: 10.28991/CEJ-2023-09-06-015 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89388786","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 : 2023-06-01DOI: 10.28991/cej-2023-09-06-08
K. Kanmani, Vasanthi P., P. Pari, N. S. S. Ahamed
Soil moisture is an essential factor that influences agricultural productivity and hydrological processes. Soil moisture estimation using field detection methods takes time and is challenging. However, using Remote Sensing (RS) and Geographic Information System (GIS) technology, soil moisture parameters become easier to detect. In microwave remote sensing, synthetic aperture radar (SAR) data helps to retrieve soil moisture from more considerable depths because of its high penetration capability and the illumination power of its light source. This study aims to process the SAR Sentinel-1A data and estimate soil moisture using the Water Cloud Model (WCM). Many physical and empirical models have been developed to determine soil moisture from microwave remote sensing platforms. However, the Water Cloud Model gives more accurate results. In this study, the WCM model is used for mixed crop types. The experimental soil moisture was determined from in-situ soil samples collected from various agricultural areas. The soil backscattering values corresponding to the different soil sampling locations were derived from Sentinel SAR data. Using linear regression analysis, the laboratory's soil moisture results and soil backscattering values were correlated to arrive at a model. The model was validated using a secondary set of in-situ moisture content values taken during the same period. The R2 and RMSE of the model were observed to be 0.825 and 0.0274, respectively, proving a strong correlation between the experimental soil moisture and satellite-derived soil moisture for mixed crop field types. This paper explains the methodology for arriving at a model for soil moisture estimation. This model helps to recommend suitable crop types in large, complex areas based on predicted moisture content. Doi: 10.28991/CEJ-2023-09-06-08 Full Text: PDF
{"title":"Estimation of Soil Moisture for Different Crops Using SAR Polarimetric Data","authors":"K. Kanmani, Vasanthi P., P. Pari, N. S. S. Ahamed","doi":"10.28991/cej-2023-09-06-08","DOIUrl":"https://doi.org/10.28991/cej-2023-09-06-08","url":null,"abstract":"Soil moisture is an essential factor that influences agricultural productivity and hydrological processes. Soil moisture estimation using field detection methods takes time and is challenging. However, using Remote Sensing (RS) and Geographic Information System (GIS) technology, soil moisture parameters become easier to detect. In microwave remote sensing, synthetic aperture radar (SAR) data helps to retrieve soil moisture from more considerable depths because of its high penetration capability and the illumination power of its light source. This study aims to process the SAR Sentinel-1A data and estimate soil moisture using the Water Cloud Model (WCM). Many physical and empirical models have been developed to determine soil moisture from microwave remote sensing platforms. However, the Water Cloud Model gives more accurate results. In this study, the WCM model is used for mixed crop types. The experimental soil moisture was determined from in-situ soil samples collected from various agricultural areas. The soil backscattering values corresponding to the different soil sampling locations were derived from Sentinel SAR data. Using linear regression analysis, the laboratory's soil moisture results and soil backscattering values were correlated to arrive at a model. The model was validated using a secondary set of in-situ moisture content values taken during the same period. The R2 and RMSE of the model were observed to be 0.825 and 0.0274, respectively, proving a strong correlation between the experimental soil moisture and satellite-derived soil moisture for mixed crop field types. This paper explains the methodology for arriving at a model for soil moisture estimation. This model helps to recommend suitable crop types in large, complex areas based on predicted moisture content. Doi: 10.28991/CEJ-2023-09-06-08 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"55 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83340916","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 : 2023-06-01DOI: 10.28991/cej-2023-09-06-04
B. Al-Abbas, Z. M. A. Abdul Rasoul, Dhafer M. Hasan, Sajjad E. Rasheed
Composite concrete Filled Tubular Steel (CFT) members, which have excellent deformability due to the well-known confined and constrained interaction between steel tube and concrete, have largely been utilized as bridge piers or columns in high-rise buildings, resulting in increased strength and decreased column size. This study examined the experimental performance of steel tube columns filled with reactive powder concrete (RPC) under axial compression. Three sets of columns were used in the experiment, each with variations in shape (square, rectangular, and circular), length-to-diameter ratio, and compressive strength of the RPC. The first set consisted of five columns, while the second and third sets each had seven columns with three different lengths (750 mm, 600 mm, and 450 mm) and two different compressive strengths (54 and 92 MPa). A new numerical model was developed to calculate the ultimate failure load of the columns by considering factors such as the yield strength of steel, the compressive strength of concrete, the column shape, and the ratio of concrete to steel. This model was validated by comparing the results obtained from the experiments to those predicted by the model, as well as by designing equations from various codes. The results showed that the proposed numerical model accurately predicted the ultimate failure load for columns filled with different types of concrete, especially for RPC, while maintaining conservatism compared to the ACI, AISC, and EN codes equations. Doi: 10.28991/CEJ-2023-09-06-04 Full Text: PDF
钢管混凝土组合构件由于钢管与混凝土之间的约束相互作用而具有优异的变形性能,已广泛用于高层建筑的桥墩或柱,从而提高了强度,减小了柱尺寸。研究了活性粉末混凝土(RPC)填充钢管柱在轴压作用下的试验性能。实验中使用了三组柱,每组柱的形状(方形、矩形和圆形)、长径比和RPC的抗压强度都有变化。第一组由五根柱子组成,第二组和第三组各有七根柱子,三种不同的长度(750 mm, 600 mm和450 mm)和两种不同的抗压强度(54和92 MPa)。考虑钢的屈服强度、混凝土的抗压强度、柱形和混凝土与钢的比例等因素,建立了计算柱的极限破坏荷载的数值模型。通过将实验结果与模型预测结果进行比较,并通过设计不同代码的方程,验证了该模型的正确性。结果表明,本文提出的数值模型能够较准确地预测不同类型混凝土填充柱(尤其是RPC)的极限破坏荷载,且与ACI、AISC和EN规范方程相比保持保守性。Doi: 10.28991/CEJ-2023-09-06-04全文:PDF
{"title":"Experimental Study on Ultimate Strength of Steel Tube Column Filled with Reactive Powder Concrete","authors":"B. Al-Abbas, Z. M. A. Abdul Rasoul, Dhafer M. Hasan, Sajjad E. Rasheed","doi":"10.28991/cej-2023-09-06-04","DOIUrl":"https://doi.org/10.28991/cej-2023-09-06-04","url":null,"abstract":"Composite concrete Filled Tubular Steel (CFT) members, which have excellent deformability due to the well-known confined and constrained interaction between steel tube and concrete, have largely been utilized as bridge piers or columns in high-rise buildings, resulting in increased strength and decreased column size. This study examined the experimental performance of steel tube columns filled with reactive powder concrete (RPC) under axial compression. Three sets of columns were used in the experiment, each with variations in shape (square, rectangular, and circular), length-to-diameter ratio, and compressive strength of the RPC. The first set consisted of five columns, while the second and third sets each had seven columns with three different lengths (750 mm, 600 mm, and 450 mm) and two different compressive strengths (54 and 92 MPa). A new numerical model was developed to calculate the ultimate failure load of the columns by considering factors such as the yield strength of steel, the compressive strength of concrete, the column shape, and the ratio of concrete to steel. This model was validated by comparing the results obtained from the experiments to those predicted by the model, as well as by designing equations from various codes. The results showed that the proposed numerical model accurately predicted the ultimate failure load for columns filled with different types of concrete, especially for RPC, while maintaining conservatism compared to the ACI, AISC, and EN codes equations. Doi: 10.28991/CEJ-2023-09-06-04 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84929283","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 : 2023-06-01DOI: 10.28991/cej-2023-09-06-017
F. Aneke, Joy Tuoyo Adu
The heavy metals (HMs) and metalloids such as Cr(VI), As(Ill), and Pb(II) in contaminated water are toxic even at trace levels and have caused devastating negative health impacts on human beings. Hence, the effective adsorption of these heavy metals from contaminated water is important to protect biodiversity, hydrosphere ecosystems, and human beings. In this study, a leachate modular tower (LMT) was developed for the singular purpose of adsorbing HMs. The LMT contained nano-slag as a liner, which was synthesized from slag. The nano-slag was blended in different proportions of 90:10; 80:20, 70:30, 60:40, and 50:50 to the combined mass of clay and nano-slag, to evaluate the most efficient ratio of the blends capable of adsorbing HMs and metalloids with 100% efficiency. A series of leachate tests were performed to evaluate the adsorption capacity of LMT with different embedded liners. Attenuation periods of 2, 5, 7, and 10 days with a temperature of 500 °C were also selected to improve the sorption rate and uptake of HMs. Subsequently, the effluents were subjected to inductive coupled plasma mass spectrometry (ICP-MS) tests to evaluate the concentrations and percentages of adsorbed HMs, which were calculated using a pseudo-first-order adsorption model. The results revealed that the removal of 98%As, 99%Cd, and 99.9% Pb was achieved with a 50%:50% ratio of soil and nano-slag as the liner at 10 days equilibrium period. Furthermore, 98%Zn, 95.45%Cu, 93.3%Fe, 97%Ni, and 89% Hg were achieved upon further investigation using the same dosage of soil and nano-slag and equilibrium conditions. The scanning electron microscopy (SEM) tests demonstrated that some traces of the absorbed HMs and metalloids were found on the liner surfaces, indicating significant changes in microstructure. The results indicated the sorption rate increased significantly due to the elevated temperature, aluminosilicate structure, and prolonged attenuation period, which are also associated with an elevated pH level and higher cation exchange capacity (CEC), of the liner. Doi: 10.28991/CEJ-2023-09-06-017 Full Text: PDF
{"title":"Adsorption of Heavy Metals from Contaminated Water using Leachate Modular Tower","authors":"F. Aneke, Joy Tuoyo Adu","doi":"10.28991/cej-2023-09-06-017","DOIUrl":"https://doi.org/10.28991/cej-2023-09-06-017","url":null,"abstract":"The heavy metals (HMs) and metalloids such as Cr(VI), As(Ill), and Pb(II) in contaminated water are toxic even at trace levels and have caused devastating negative health impacts on human beings. Hence, the effective adsorption of these heavy metals from contaminated water is important to protect biodiversity, hydrosphere ecosystems, and human beings. In this study, a leachate modular tower (LMT) was developed for the singular purpose of adsorbing HMs. The LMT contained nano-slag as a liner, which was synthesized from slag. The nano-slag was blended in different proportions of 90:10; 80:20, 70:30, 60:40, and 50:50 to the combined mass of clay and nano-slag, to evaluate the most efficient ratio of the blends capable of adsorbing HMs and metalloids with 100% efficiency. A series of leachate tests were performed to evaluate the adsorption capacity of LMT with different embedded liners. Attenuation periods of 2, 5, 7, and 10 days with a temperature of 500 °C were also selected to improve the sorption rate and uptake of HMs. Subsequently, the effluents were subjected to inductive coupled plasma mass spectrometry (ICP-MS) tests to evaluate the concentrations and percentages of adsorbed HMs, which were calculated using a pseudo-first-order adsorption model. The results revealed that the removal of 98%As, 99%Cd, and 99.9% Pb was achieved with a 50%:50% ratio of soil and nano-slag as the liner at 10 days equilibrium period. Furthermore, 98%Zn, 95.45%Cu, 93.3%Fe, 97%Ni, and 89% Hg were achieved upon further investigation using the same dosage of soil and nano-slag and equilibrium conditions. The scanning electron microscopy (SEM) tests demonstrated that some traces of the absorbed HMs and metalloids were found on the liner surfaces, indicating significant changes in microstructure. The results indicated the sorption rate increased significantly due to the elevated temperature, aluminosilicate structure, and prolonged attenuation period, which are also associated with an elevated pH level and higher cation exchange capacity (CEC), of the liner. Doi: 10.28991/CEJ-2023-09-06-017 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79830492","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 : 2023-06-01DOI: 10.28991/cej-2023-09-06-011
A. Youssef, M. Hegazy, Hatem Mostafa
This research aims to illustrate the corrosion process and its effect on the deterioration of reinforced concrete (RC) isolated footings using a small-scale model (1/8) and present the results of a prototype-scale study using a numerical model with different concrete depths and corrosion levels under axial load. The experimental program consisted of testing five small-scale (1/8) model RC isolated footings under axial loading after subjecting them to accelerated corrosion tests with a constant current. The main variable in the small-scale sample test was the corrosion level. This study presents an experimental approach, using the constant current method and the finite element method (FEM) with the ABAQUS package, to examine its effect on the axial load behavior under different corrosion ratios, which were 0%, 4.21%, 9.11%, 24.56%, and 30.67%. On the prototype scale, the variables were the corrosion level and the RC depths of 300 mm, 400 mm, and 500 mm. The results indicated that the average deviation in ultimate load between the experimental and FEM outcomes for the small-scale was below 5.6%, while the average deflection deviation was 6.8%. Also, the study found that an increase in the depth of the RC footing and corrosion ratio led to a more pronounced impact of the cracking pattern in the concrete and corroded bars, as well as a greater difference in the failure load. The experimental results suggest that the proposed numerical model is accurate and effective. These findings have important implications for the evaluation of isolated footings affected by corrosion damage using FEM, and can help inform decisions related to their design and maintenance. The failure loads of non-corroded footings with different depths were compared with the ECP-203 provisions of the 2018 Egyptian Code, and how corrosion ratios can be simulated by numerical models. The percentage variation between the design loads by code and the numerical loads by ABAQUS for controlled footings with thicknesses of 300, 400, and 500 mm was found to be 73%, 80%, and 78%, respectively. Using the derived relationship, the equivalent corrosion ratio percentages were 23.8%, 20.2%, and 32%, respectively. Doi: 10.28991/CEJ-2023-09-06-011 Full Text: PDF
{"title":"Performance of Isolated Footing with Several Corrosion Levels under Axial Loading","authors":"A. Youssef, M. Hegazy, Hatem Mostafa","doi":"10.28991/cej-2023-09-06-011","DOIUrl":"https://doi.org/10.28991/cej-2023-09-06-011","url":null,"abstract":"This research aims to illustrate the corrosion process and its effect on the deterioration of reinforced concrete (RC) isolated footings using a small-scale model (1/8) and present the results of a prototype-scale study using a numerical model with different concrete depths and corrosion levels under axial load. The experimental program consisted of testing five small-scale (1/8) model RC isolated footings under axial loading after subjecting them to accelerated corrosion tests with a constant current. The main variable in the small-scale sample test was the corrosion level. This study presents an experimental approach, using the constant current method and the finite element method (FEM) with the ABAQUS package, to examine its effect on the axial load behavior under different corrosion ratios, which were 0%, 4.21%, 9.11%, 24.56%, and 30.67%. On the prototype scale, the variables were the corrosion level and the RC depths of 300 mm, 400 mm, and 500 mm. The results indicated that the average deviation in ultimate load between the experimental and FEM outcomes for the small-scale was below 5.6%, while the average deflection deviation was 6.8%. Also, the study found that an increase in the depth of the RC footing and corrosion ratio led to a more pronounced impact of the cracking pattern in the concrete and corroded bars, as well as a greater difference in the failure load. The experimental results suggest that the proposed numerical model is accurate and effective. These findings have important implications for the evaluation of isolated footings affected by corrosion damage using FEM, and can help inform decisions related to their design and maintenance. The failure loads of non-corroded footings with different depths were compared with the ECP-203 provisions of the 2018 Egyptian Code, and how corrosion ratios can be simulated by numerical models. The percentage variation between the design loads by code and the numerical loads by ABAQUS for controlled footings with thicknesses of 300, 400, and 500 mm was found to be 73%, 80%, and 78%, respectively. Using the derived relationship, the equivalent corrosion ratio percentages were 23.8%, 20.2%, and 32%, respectively. Doi: 10.28991/CEJ-2023-09-06-011 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"119 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77453588","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 : 2023-06-01DOI: 10.28991/cej-2023-09-06-014
Muhamet Ahmeti, M. Ahmetaj, V. Krelani
Objective: This study investigated the possibility of using recycled asphalt for road construction and maintenance in Kosovo. Methods: By analyzing statistical data from the Ministry of Infrastructure based on the status of infrastructure, the life cycle of asphalt, and investments in this area, this study determined the amount of asphalt that needs to be recycled. Results: The results showed that 1454008.5 m3 of asphalt needs to be recycled in Kosovo. We studied using 10%, 15%, and 20% recycled asphalt in asphalt base courses. We determined the benefits of recycled asphalt in terms of environmental protection, energy savings, and low cost. Depending on the percentage of recycled asphalt, the savings in mineral mix ranged from 11% to 23% and the road bitumen dosage from 6 to 8.5%. Novelty/Improvement: The proposed method of reusing recycled materials can reduce the consumption of natural resources, energy, and financial costs and help protect the environment. Doi: 10.28991/CEJ-2023-09-06-014 Full Text: PDF
{"title":"Evaluating the Potential of Recycled Asphalt for Sustainable Road Construction: An Environmental and Economic Analysis","authors":"Muhamet Ahmeti, M. Ahmetaj, V. Krelani","doi":"10.28991/cej-2023-09-06-014","DOIUrl":"https://doi.org/10.28991/cej-2023-09-06-014","url":null,"abstract":"Objective: This study investigated the possibility of using recycled asphalt for road construction and maintenance in Kosovo. Methods: By analyzing statistical data from the Ministry of Infrastructure based on the status of infrastructure, the life cycle of asphalt, and investments in this area, this study determined the amount of asphalt that needs to be recycled. Results: The results showed that 1454008.5 m3 of asphalt needs to be recycled in Kosovo. We studied using 10%, 15%, and 20% recycled asphalt in asphalt base courses. We determined the benefits of recycled asphalt in terms of environmental protection, energy savings, and low cost. Depending on the percentage of recycled asphalt, the savings in mineral mix ranged from 11% to 23% and the road bitumen dosage from 6 to 8.5%. Novelty/Improvement: The proposed method of reusing recycled materials can reduce the consumption of natural resources, energy, and financial costs and help protect the environment. Doi: 10.28991/CEJ-2023-09-06-014 Full Text: PDF","PeriodicalId":53612,"journal":{"name":"Open Civil Engineering Journal","volume":"106 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86971625","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}