This study was conducted to investigate the physical and geo-mechanical properties such as specific gravity, porosity, uniaxial compressive strength (UCS) etc. of shale, hosting lead and zinc ore in Enyigba, Ebonyi State, Nigeria. The strength properties of the black shale were analyzed because the variability in the strength of rock masses must be properly accounted for, to determine their utility in engineering design. Several tests were carried out on the intact shale samples, and the results were converted to bulk mass strength values using the Hoek–Brown criterion. The results showed that the UCS of the black shale ranged from 38.3 to 43.7 MPa for a geological strength index (GSI) value of 75; and from 54.2 to 60.4 MPa for a GSI value of 80. The specific gravity was 2.89 while the bulk density and porosity values were 290.3 kg/m3 and 15.56% respectively. Also, it was determined that there is a strong correlation between the UCS and specific gravity of the rock, with negligible levels of correlation, both positive and negative, between the UCS and the other mechanical properties examined. In conclusion, the black shale sample from Enyigba is characterized as a medium to hard rock that is suitable for engineering and mining projects.
{"title":"Determination of Physical and Geomechanical Properties of Black Shale Hosting Lead and Zinc Ore in Eyingba, Ebonyi","authors":"Ige Ibukun","doi":"10.36937/ben.2023.4827","DOIUrl":"https://doi.org/10.36937/ben.2023.4827","url":null,"abstract":"This study was conducted to investigate the physical and geo-mechanical properties such as specific gravity, porosity, uniaxial compressive strength (UCS) etc. of shale, hosting lead and zinc ore in Enyigba, Ebonyi State, Nigeria. The strength properties of the black shale were analyzed because the variability in the strength of rock masses must be properly accounted for, to determine their utility in engineering design. Several tests were carried out on the intact shale samples, and the results were converted to bulk mass strength values using the Hoek–Brown criterion. The results showed that the UCS of the black shale ranged from 38.3 to 43.7 MPa for a geological strength index (GSI) value of 75; and from 54.2 to 60.4 MPa for a GSI value of 80. The specific gravity was 2.89 while the bulk density and porosity values were 290.3 kg/m3 and 15.56% respectively. Also, it was determined that there is a strong correlation between the UCS and specific gravity of the rock, with negligible levels of correlation, both positive and negative, between the UCS and the other mechanical properties examined. In conclusion, the black shale sample from Enyigba is characterized as a medium to hard rock that is suitable for engineering and mining projects.","PeriodicalId":512316,"journal":{"name":"October 2023","volume":"36 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139455647","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}
Geopolymer concrete, a sustainable and durable alternative to conventional Portland cement-based concrete, has gained significant attention in recent years. Its reduced carbon footprint and superior mechanical properties make it a viable option for various construction applications. However, acid resistance remains a critical area of concern, particularly in environments where exposure to acidic substances is prevalent. This review paper delves into the acid resistance of geopolymer concrete, providing a comprehensive overview of the latest research findings, methodologies, and advancements in the field. The paper commences by exploring the fundamental principles of geopolymer chemistry. Subsequently, the paper meticulously reviews the experimental results of studies investigating the acid resistance of geopolymer concrete. It focuses on the effects of various acids commonly encountered in industrial and environmental settings, such as sulfuric acid, hydrochloric acid, and organic acids. The paper summarizes the key findings from the reviewed literature, highlighting the strengths and limitations of geopolymer concrete in terms of acid resistance. It identifies the factors that contribute to enhanced acid resistance and suggests potential strategies for further improvement. Furthermore, the paper outlines future research directions, emphasizing the need for long-term studies, the development of standardized testing methods, and the exploration of novel geopolymer formulations with superior acid resistance.
{"title":"Acid Resistance of Geopolymer Concrete – Literature Review, Knowledge Gaps, and Future Development","authors":"Md. Ibrahim Mostazid","doi":"10.36937/ben.2023.4875","DOIUrl":"https://doi.org/10.36937/ben.2023.4875","url":null,"abstract":"Geopolymer concrete, a sustainable and durable alternative to conventional Portland cement-based concrete, has gained significant attention in recent years. Its reduced carbon footprint and superior mechanical properties make it a viable option for various construction applications. However, acid resistance remains a critical area of concern, particularly in environments where exposure to acidic substances is prevalent. This review paper delves into the acid resistance of geopolymer concrete, providing a comprehensive overview of the latest research findings, methodologies, and advancements in the field. The paper commences by exploring the fundamental principles of geopolymer chemistry. Subsequently, the paper meticulously reviews the experimental results of studies investigating the acid resistance of geopolymer concrete. It focuses on the effects of various acids commonly encountered in industrial and environmental settings, such as sulfuric acid, hydrochloric acid, and organic acids. The paper summarizes the key findings from the reviewed literature, highlighting the strengths and limitations of geopolymer concrete in terms of acid resistance. It identifies the factors that contribute to enhanced acid resistance and suggests potential strategies for further improvement. Furthermore, the paper outlines future research directions, emphasizing the need for long-term studies, the development of standardized testing methods, and the exploration of novel geopolymer formulations with superior acid resistance.","PeriodicalId":512316,"journal":{"name":"October 2023","volume":"117 40","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139453711","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}
Refractory materials are indispensable for industries working with high temperatures. Magnesite spinel refractory bricks are used in the cement industry, and calcium lignosulfonate is used as a binder in their production. Due to forest fires and similar reasons in recent years, there is a problem in the supply of calcium lignosulfonate raw materials. In this study, research was conducted on alternative binders to be used in the production of magnesite spinel bricks and the optimum conditions for production with the selected binder were determined. Some of the binders are calcium naphthalene sulfonate, sodium naphthalene sulfonate, magnesium oxide, magnesium sulfate, and molasses. As a result of preliminary tests, it was observed that the most successful results were obtained with calcium naphthalene sulfonate. The optimum conditions for the production of magnesite spinel refractory bricks using calcium naphthalene sulfonate were found by the Taguchi method. As parameters, seawater sintered magnesite in 4 different fractions (A: 3-5 mm, B: 1-3 mm, C: 0-1 mm and D: Powder) and Sinter Spinel in 2 different fractions (E: 3-5 mm and F: 1-3 mm) in total, 6 parameters were selected and an L16 (44x22) Taguchi orthogonal array design was created for this. Volume weight, water absorption, porosity, and strength tests were performed on the samples obtained. Accordingly, taking into account the strength values, the optimum conditions were determined as A1, B1, C2, D4, E1 and F2. Under these conditions, the estimated strength value was calculated as 84.24 N/mm2 and the experimental value was 83.85 N/mm2.
{"title":"Investigation of The Use of Calcium Naphthalene Sulfonate as A Binder in Magnesite Spinel Brick Production and Determination of Optimum Conditions","authors":"Özkan Küçük","doi":"10.36937/ben.2023.4890","DOIUrl":"https://doi.org/10.36937/ben.2023.4890","url":null,"abstract":"Refractory materials are indispensable for industries working with high temperatures. Magnesite spinel refractory bricks are used in the cement industry, and calcium lignosulfonate is used as a binder in their production. Due to forest fires and similar reasons in recent years, there is a problem in the supply of calcium lignosulfonate raw materials. In this study, research was conducted on alternative binders to be used in the production of magnesite spinel bricks and the optimum conditions for production with the selected binder were determined. Some of the binders are calcium naphthalene sulfonate, sodium naphthalene sulfonate, magnesium oxide, magnesium sulfate, and molasses. As a result of preliminary tests, it was observed that the most successful results were obtained with calcium naphthalene sulfonate. The optimum conditions for the production of magnesite spinel refractory bricks using calcium naphthalene sulfonate were found by the Taguchi method. As parameters, seawater sintered magnesite in 4 different fractions (A: 3-5 mm, B: 1-3 mm, C: 0-1 mm and D: Powder) and Sinter Spinel in 2 different fractions (E: 3-5 mm and F: 1-3 mm) in total, 6 parameters were selected and an L16 (44x22) Taguchi orthogonal array design was created for this. Volume weight, water absorption, porosity, and strength tests were performed on the samples obtained. Accordingly, taking into account the strength values, the optimum conditions were determined as A1, B1, C2, D4, E1 and F2. Under these conditions, the estimated strength value was calculated as 84.24 N/mm2 and the experimental value was 83.85 N/mm2.","PeriodicalId":512316,"journal":{"name":"October 2023","volume":"108 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139454319","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 : 2024-01-01DOI: 10.36937/cebel.2023.1891
Elif Ağcakoca
In this article, experimental and finite element analysis studies were carried out at different impact heights of steel beams with different geometric cross-sections. The behavior of elements with varying cross-sectional properties was examined when subjected to hammer loads dropped from different heights. In the experimental study, boundary conditions were established using a 2000 mm long rectangular cross-section beam element with pin and roller supports. The behavior of the steel beam under impact load was analyzed using Abaqus Explicit three-dimensional finite element models. Subsequently, a validation process ensuring convergence was performed before conducting a parametric study. 6 finite element models were constructed for the parametric study, comprising circular and ellipse-section steel elements with approximately equivalent unit weights. The cross-sectional geometry and hammer height were varied while keeping the boundary conditions consistent with the samples examined. As the height of the hammer drop increased, the displacement value, Von-Mises stress, and PEEQ (plastic equivalent strain) values of the elements also increased. When transitioning the cross-sectional shape of the beam element from a circle to an ellipse at a constant hammer height, it resulted in a decrease in the displacement value, Von-Mises stress, and PEEQ values. The results indicate that the maximum displacement, highest stress, and PEEQ value are observed in the E#2000 scenario. Similarly, the smallest displacement, lowest stress, and PEEQ value are exhibited in the C#1400 case.
{"title":"Behavior of Steel Sections with Different Geometries Under Impact Load","authors":"Elif Ağcakoca","doi":"10.36937/cebel.2023.1891","DOIUrl":"https://doi.org/10.36937/cebel.2023.1891","url":null,"abstract":"In this article, experimental and finite element analysis studies were carried out at different impact heights of steel beams with different geometric cross-sections. The behavior of elements with varying cross-sectional properties was examined when subjected to hammer loads dropped from different heights. In the experimental study, boundary conditions were established using a 2000 mm long rectangular cross-section beam element with pin and roller supports. The behavior of the steel beam under impact load was analyzed using Abaqus Explicit three-dimensional finite element models. Subsequently, a validation process ensuring convergence was performed before conducting a parametric study. 6 finite element models were constructed for the parametric study, comprising circular and ellipse-section steel elements with approximately equivalent unit weights. The cross-sectional geometry and hammer height were varied while keeping the boundary conditions consistent with the samples examined. As the height of the hammer drop increased, the displacement value, Von-Mises stress, and PEEQ (plastic equivalent strain) values of the elements also increased. When transitioning the cross-sectional shape of the beam element from a circle to an ellipse at a constant hammer height, it resulted in a decrease in the displacement value, Von-Mises stress, and PEEQ values. The results indicate that the maximum displacement, highest stress, and PEEQ value are observed in the E#2000 scenario. Similarly, the smallest displacement, lowest stress, and PEEQ value are exhibited in the C#1400 case.","PeriodicalId":512316,"journal":{"name":"October 2023","volume":"13 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140524529","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}
Understanding local conditions is crucial for applying soil stabilization principles from other regions to a specific country for effective and sustainable stabilization methods. This investigative study delves into the suitability of locally available Rice Husk Ash (RHA) for incorporation into local building construction practices at Dinajpur, Bangladesh, aiming to minimize the volume of waste disposed of in the environment, thereby mitigating environmental pollution. Conventional soil stabilization techniques are becoming increasingly expensive due to the rising costs of stabilizing agents such as cement. Replacing a portion of the stabilizing agent with RHA could potentially reduce the cost of stabilization while also minimizing environmental harm. RHA comprises 85-90% silica, making it an excellent substitute for silica in soil stabilization. Silica is recognized as an effective binding agent alongside cement. The soil sample selected for this research is a highly plastic clay (CH), which necessitates significant strength enhancement. Three soil samples were stabilized with varying percentages of RHA and a minimal amount of cement. Observations were made to assess the changes in soil properties, including Maximum Dry Density (MDD), Optimum Moisture Content (OMC), and Unconfined Compressive Strength (UCS). The results obtained indicate that increasing RHA content leads to an increase in MDD but a decrease in OMC. Additionally, the UCS of the soil exhibits substantial improvement to up to 88% with increasing RHA content up to 10%. Based on the observed maximum strength enhancement, a 10% RHA content combined with 6% cement is recommended as the optimal combination for practical applications.
{"title":"Effect of rice husk ash on soil stabilization at Dinajpur City","authors":"Md. Ibrahim Mostazid","doi":"10.36937/ben.2023.4885","DOIUrl":"https://doi.org/10.36937/ben.2023.4885","url":null,"abstract":"Understanding local conditions is crucial for applying soil stabilization principles from other regions to a specific country for effective and sustainable stabilization methods. This investigative study delves into the suitability of locally available Rice Husk Ash (RHA) for incorporation into local building construction practices at Dinajpur, Bangladesh, aiming to minimize the volume of waste disposed of in the environment, thereby mitigating environmental pollution. Conventional soil stabilization techniques are becoming increasingly expensive due to the rising costs of stabilizing agents such as cement. Replacing a portion of the stabilizing agent with RHA could potentially reduce the cost of stabilization while also minimizing environmental harm. RHA comprises 85-90% silica, making it an excellent substitute for silica in soil stabilization. Silica is recognized as an effective binding agent alongside cement. The soil sample selected for this research is a highly plastic clay (CH), which necessitates significant strength enhancement. Three soil samples were stabilized with varying percentages of RHA and a minimal amount of cement. Observations were made to assess the changes in soil properties, including Maximum Dry Density (MDD), Optimum Moisture Content (OMC), and Unconfined Compressive Strength (UCS). The results obtained indicate that increasing RHA content leads to an increase in MDD but a decrease in OMC. Additionally, the UCS of the soil exhibits substantial improvement to up to 88% with increasing RHA content up to 10%. Based on the observed maximum strength enhancement, a 10% RHA content combined with 6% cement is recommended as the optimal combination for practical applications.","PeriodicalId":512316,"journal":{"name":"October 2023","volume":" 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139391733","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}
Today, cancer diagnosis and treatment with the THz radiation model (THz wave ablation) is a subject of interest to researchers. The design performance of THz ablation systems depends on the design of a waveguide that will provide low-loss transmission of radiation from the antenna to the tissue. In this study, first of all, the superiority of graphene over noble metal is demonstrated. Then, the performance of THz rectangular waveguides which use graphene cladding and different core materials such as Silicon (Si), Silica (SiO2), Zeonex, Teflon, and PMMA (Polymethyl methacrylate) are comparatively investigated. The electromagnetic field distribution, transmission coefficients (S21), attenuation constant (dB/mm), and effective refractive index (neff) are analyzed in Computer Simulation Technology Studio Suit software to see the effect of various core materials on the characteristic of rectangular waveguides. Obtained simulation results show that Si, Teflon, and Zeonex have high transmission performance with ≈-0.5 dB. In addition, in the wavelength range where the operating performance of the waveguide is examined, Teflon and Zeonex perform well with an attenuation constant of less than 0.096 dB/mm. Electric field distributions of Teflon and Zeonex confirm that the transmission performance is better than others. In conclusion, Teflon and Zeonex materials are handy and promising for the 1.65 THz ablation system.
{"title":"A Comparative Analysis of Graphene Cladding Rectangular Waveguides Filled with Various Materials for 1.65 THz Ablation System","authors":"H. K. Polat","doi":"10.36937/ben.2023.4880","DOIUrl":"https://doi.org/10.36937/ben.2023.4880","url":null,"abstract":"Today, cancer diagnosis and treatment with the THz radiation model (THz wave ablation) is a subject of interest to researchers. The design performance of THz ablation systems depends on the design of a waveguide that will provide low-loss transmission of radiation from the antenna to the tissue. In this study, first of all, the superiority of graphene over noble metal is demonstrated. Then, the performance of THz rectangular waveguides which use graphene cladding and different core materials such as Silicon (Si), Silica (SiO2), Zeonex, Teflon, and PMMA (Polymethyl methacrylate) are comparatively investigated. The electromagnetic field distribution, transmission coefficients (S21), attenuation constant (dB/mm), and effective refractive index (neff) are analyzed in Computer Simulation Technology Studio Suit software to see the effect of various core materials on the characteristic of rectangular waveguides. Obtained simulation results show that Si, Teflon, and Zeonex have high transmission performance with ≈-0.5 dB. In addition, in the wavelength range where the operating performance of the waveguide is examined, Teflon and Zeonex perform well with an attenuation constant of less than 0.096 dB/mm. Electric field distributions of Teflon and Zeonex confirm that the transmission performance is better than others. In conclusion, Teflon and Zeonex materials are handy and promising for the 1.65 THz ablation system.","PeriodicalId":512316,"journal":{"name":"October 2023","volume":"3 20","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139457799","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：