N. Ahmed, Faten Kamil, Adnan Ali Hasso, A. N. Abduljawaad, Thekra Fadel Saleh, S. Mahmood
Abstract Avian eggshell is a natural biomaterial that has been used as an alternative natural source of CaCO3 and is accessible in big amounts from egg manufacturing. This study was planned to estimate CaCO3 in quail’s eggshell because it has a probable use in the progress of a novel choice of many applications. Physical properties: mineralogical documentation of the natural eggshell nanoparticles were approved using XRD and FTIR to explore the chemical bond or molecular structure of the materials. Micrographs were obtained using FESEM/EDX and TEM to identify the morphology and size of nanoparticles. The results showed that quail eggshell was soft, with white to light sand color, and a smooth texture which allows good deposition of different color spots, from black to brown spots. The resulted of eggshells signifies almost 8.4% w/w of the overall weight (12.2) gram of quail egg and 91.60% w/w of the micropowder to the full weight of (0.94) gram of quail eggshell. The results presented that calcium is the main element in an eggshell; frequently occurs in a formula of CaCO3 and the crystal construction was almost pure calcite. FTIR spectra for quail eggshell demonstrated the existence of the out of plane bending, the asymmetric stretching, and the plane bending styles of the carbonate groups, specific of normal dolomite, situated at 873 cm–1, 1405 cm–1, and 710 cm–1, respectively. The FESEM and TEM for nanoparticles were shown calcite CaCO3 nanoparticles with an ordinary size of ≤ 100 nm for FESEM and with a variety size of ≤ 50 nm for TEM. Unfortunately, eggshell is an egg product manufacturing deposit. These incomes will let fast developments in proportional studies of the organic elements of avian eggshell and their purposeful consequences by usages of eggshell in nourishment and medicine which can be applied for many resolutions that diminish their consequence on environmental contamination.
{"title":"Calcium carbonate nanoparticles of quail’s egg shells: Synthesis and characterizations","authors":"N. Ahmed, Faten Kamil, Adnan Ali Hasso, A. N. Abduljawaad, Thekra Fadel Saleh, S. Mahmood","doi":"10.1515/jmbm-2022-0001","DOIUrl":"https://doi.org/10.1515/jmbm-2022-0001","url":null,"abstract":"Abstract Avian eggshell is a natural biomaterial that has been used as an alternative natural source of CaCO3 and is accessible in big amounts from egg manufacturing. This study was planned to estimate CaCO3 in quail’s eggshell because it has a probable use in the progress of a novel choice of many applications. Physical properties: mineralogical documentation of the natural eggshell nanoparticles were approved using XRD and FTIR to explore the chemical bond or molecular structure of the materials. Micrographs were obtained using FESEM/EDX and TEM to identify the morphology and size of nanoparticles. The results showed that quail eggshell was soft, with white to light sand color, and a smooth texture which allows good deposition of different color spots, from black to brown spots. The resulted of eggshells signifies almost 8.4% w/w of the overall weight (12.2) gram of quail egg and 91.60% w/w of the micropowder to the full weight of (0.94) gram of quail eggshell. The results presented that calcium is the main element in an eggshell; frequently occurs in a formula of CaCO3 and the crystal construction was almost pure calcite. FTIR spectra for quail eggshell demonstrated the existence of the out of plane bending, the asymmetric stretching, and the plane bending styles of the carbonate groups, specific of normal dolomite, situated at 873 cm–1, 1405 cm–1, and 710 cm–1, respectively. The FESEM and TEM for nanoparticles were shown calcite CaCO3 nanoparticles with an ordinary size of ≤ 100 nm for FESEM and with a variety size of ≤ 50 nm for TEM. Unfortunately, eggshell is an egg product manufacturing deposit. These incomes will let fast developments in proportional studies of the organic elements of avian eggshell and their purposeful consequences by usages of eggshell in nourishment and medicine which can be applied for many resolutions that diminish their consequence on environmental contamination.","PeriodicalId":17354,"journal":{"name":"Journal of the Mechanical Behavior of Materials","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43840309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract With the spread of the use of liquefied petroleum gas (LPG) in developing countries for use in domestic cooking with the increase in the expansion and distribution of gas pipelines for residential buildings, the 2002 World Summit focused on sustainable development in clean energy for natural gas (NG) and LPG. The research aims to focus on the important aspects of design sustainability from an environmental point of view to reduce gas leakage, accidents, and explosions that occur socially to expand the distribution of LPG and motivate the consumers to use it instead of natural gas and other fuels, and from an economic point of view to take into account the annual cost and aesthetic impact of maintaining on the view of the building and the design of the pipes in ways that do not distort the public view. The study area was a building in a residential complex in Baghdad and the gas pipelines were connected to the building completely for studying. The axes of sustainability were applied to the building in an analysis method using the goals achievement matrix, which is divided into main goals and secondary goals. The results showed that the environmental and aesthetic sustainability were well applied to the building, but from a social point of view, in the dissemination of safety instructions to the consumer, and from a financial point of view, there were shortcomings in them, and this could lead to long-term damage to the building.
{"title":"Sustainability in the design of liquefied petroleum gas systems used in buildings","authors":"Amna Amer Farouq, B. Al-Obaidi","doi":"10.1515/jmbm-2022-0027","DOIUrl":"https://doi.org/10.1515/jmbm-2022-0027","url":null,"abstract":"Abstract With the spread of the use of liquefied petroleum gas (LPG) in developing countries for use in domestic cooking with the increase in the expansion and distribution of gas pipelines for residential buildings, the 2002 World Summit focused on sustainable development in clean energy for natural gas (NG) and LPG. The research aims to focus on the important aspects of design sustainability from an environmental point of view to reduce gas leakage, accidents, and explosions that occur socially to expand the distribution of LPG and motivate the consumers to use it instead of natural gas and other fuels, and from an economic point of view to take into account the annual cost and aesthetic impact of maintaining on the view of the building and the design of the pipes in ways that do not distort the public view. The study area was a building in a residential complex in Baghdad and the gas pipelines were connected to the building completely for studying. The axes of sustainability were applied to the building in an analysis method using the goals achievement matrix, which is divided into main goals and secondary goals. The results showed that the environmental and aesthetic sustainability were well applied to the building, but from a social point of view, in the dissemination of safety instructions to the consumer, and from a financial point of view, there were shortcomings in them, and this could lead to long-term damage to the building.","PeriodicalId":17354,"journal":{"name":"Journal of the Mechanical Behavior of Materials","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42522783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Public procurement in Iraq plays an essential function in the development and recovery of the country's economy as well as providing the essential infrastructure for the growth of the private sector. The Coalition Provisional Authority's Government Procurement Legislation No. 87 (2004) is the final procurement law in effect in Iraq. Preparations are underway for new procurement legislation as of Oct. 2021. The objective of the paper is to determine the effectiveness of the public procurement process used in a construction project in Iraq, there is also a lack of procurement methods and policy consistency between government agencies. procurement techniques, tender documentation information, Advertising deadlines, and document management procedures, for example, vary amongst federal contracting agencies. Furthermore, there is no mandatory process for the definition and disclosure of tender evaluation criteria, providing room for subjectivity in the tender award process. This paper's major conclusion that is competitive tendering is open to everyone, tendering is not mandated as Iraq's general rule, despite the fact that it is considered best practice elsewhere. Direct invitation techniques are widely used in the construction project process tendering of Iraq and if not adequately managed, they can lead to bias, fraud, and corruption.
{"title":"Procurement challenges analysis of Iraqi construction projects","authors":"Sadeq Abdul Hamza, Sawsan M. Rasheed, A. Hussein","doi":"10.1515/jmbm-2022-0012","DOIUrl":"https://doi.org/10.1515/jmbm-2022-0012","url":null,"abstract":"Abstract Public procurement in Iraq plays an essential function in the development and recovery of the country's economy as well as providing the essential infrastructure for the growth of the private sector. The Coalition Provisional Authority's Government Procurement Legislation No. 87 (2004) is the final procurement law in effect in Iraq. Preparations are underway for new procurement legislation as of Oct. 2021. The objective of the paper is to determine the effectiveness of the public procurement process used in a construction project in Iraq, there is also a lack of procurement methods and policy consistency between government agencies. procurement techniques, tender documentation information, Advertising deadlines, and document management procedures, for example, vary amongst federal contracting agencies. Furthermore, there is no mandatory process for the definition and disclosure of tender evaluation criteria, providing room for subjectivity in the tender award process. This paper's major conclusion that is competitive tendering is open to everyone, tendering is not mandated as Iraq's general rule, despite the fact that it is considered best practice elsewhere. Direct invitation techniques are widely used in the construction project process tendering of Iraq and if not adequately managed, they can lead to bias, fraud, and corruption.","PeriodicalId":17354,"journal":{"name":"Journal of the Mechanical Behavior of Materials","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42074821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Few studies have been conducted on the structural behavior of steel columns with branches that are called tree-like columns. These kinds of columns have been used in many structures around the world. The purpose of this study is to investigate the failure load, vertical and lateral displacement, and failure mode of tree-like columns subjected to a combination of axial and lateral loading. The ratio of lateral load to axial load has been selected as the design variable. A finite element model with one branching level and two branches within the level was first developed using ABAQUS/CAE 2017 software. The model was verified with experimental results. The axial failure load and axial and lateral displacement were determined and compared for different loading ratios. The failure mode was also studied for different loading conditions. The results showed that the axial failure load decreased significantly by 54, 42, and 28% when lateral/axial loading ratio increased by 20, 40, and 60%, respectively. There was no significant decrease when lateral/axial loading ratio was more than 60%, while axial and lateral displacements increased significantly by 24% for each 20% increase in the loading ratio. Local buckling was observed as a failure mode when only gravity load is applied, while combined load resulted in lateral buckling.
{"title":"Structural behavior of tree-like steel columns subjected to combined axial and lateral loads","authors":"Rabab C. Dekhn, K. Shadhan","doi":"10.1515/jmbm-2022-0030","DOIUrl":"https://doi.org/10.1515/jmbm-2022-0030","url":null,"abstract":"Abstract Few studies have been conducted on the structural behavior of steel columns with branches that are called tree-like columns. These kinds of columns have been used in many structures around the world. The purpose of this study is to investigate the failure load, vertical and lateral displacement, and failure mode of tree-like columns subjected to a combination of axial and lateral loading. The ratio of lateral load to axial load has been selected as the design variable. A finite element model with one branching level and two branches within the level was first developed using ABAQUS/CAE 2017 software. The model was verified with experimental results. The axial failure load and axial and lateral displacement were determined and compared for different loading ratios. The failure mode was also studied for different loading conditions. The results showed that the axial failure load decreased significantly by 54, 42, and 28% when lateral/axial loading ratio increased by 20, 40, and 60%, respectively. There was no significant decrease when lateral/axial loading ratio was more than 60%, while axial and lateral displacements increased significantly by 24% for each 20% increase in the loading ratio. Local buckling was observed as a failure mode when only gravity load is applied, while combined load resulted in lateral buckling.","PeriodicalId":17354,"journal":{"name":"Journal of the Mechanical Behavior of Materials","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42606211","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}
C. Rajarajan, P. Sivaraj, Tushar Sonar, S. Raja, N. Mathiazhagan
Abstract The main objective of this research paper is to study the microstructural features and mechanical properties of resistance spot welded advanced high-strength steel of dual phase grade in lap joint configuration which is mainly employed in sheet form for fabrication of the automotive structure. Resistance spot welding (RSW) being a solid-state welding (SSW) process is used to overcome the problems in fusion welding of AHSS-DP steel such as heat affected zone (HAZ) softening, solidification cracking and distortion which significantly deteriorates the mechanical properties of AHSS-DP800 steel joints. The straight lap (SL-TSFL) and cross lap tensile shear fracture load (CL-TSFL) of spot joints were evaluated. Optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques were used to characterize the weld nugget. The X-ray diffraction (XRD) results are also presented for phase identification in the weld nugget. The fracture surface of failed TSFL specimens was analyzed using SEM. The lap joints made using RSW disclosed superior SL-TSFL, CL-TSFL, and WNZH of 21.7 kN, 17.65 kN, and 589 HV0.5 The superior joint strength and hardness of the weld nugget zone are correlated to the evolution of lath martensite in the nugget zone.
{"title":"Investigation on microstructural features and tensile shear fracture properties of resistance spot welded advanced high strength dual phase steel sheets in lap joint configuration for automotive frame applications","authors":"C. Rajarajan, P. Sivaraj, Tushar Sonar, S. Raja, N. Mathiazhagan","doi":"10.1515/jmbm-2022-0006","DOIUrl":"https://doi.org/10.1515/jmbm-2022-0006","url":null,"abstract":"Abstract The main objective of this research paper is to study the microstructural features and mechanical properties of resistance spot welded advanced high-strength steel of dual phase grade in lap joint configuration which is mainly employed in sheet form for fabrication of the automotive structure. Resistance spot welding (RSW) being a solid-state welding (SSW) process is used to overcome the problems in fusion welding of AHSS-DP steel such as heat affected zone (HAZ) softening, solidification cracking and distortion which significantly deteriorates the mechanical properties of AHSS-DP800 steel joints. The straight lap (SL-TSFL) and cross lap tensile shear fracture load (CL-TSFL) of spot joints were evaluated. Optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques were used to characterize the weld nugget. The X-ray diffraction (XRD) results are also presented for phase identification in the weld nugget. The fracture surface of failed TSFL specimens was analyzed using SEM. The lap joints made using RSW disclosed superior SL-TSFL, CL-TSFL, and WNZH of 21.7 kN, 17.65 kN, and 589 HV0.5 The superior joint strength and hardness of the weld nugget zone are correlated to the evolution of lath martensite in the nugget zone.","PeriodicalId":17354,"journal":{"name":"Journal of the Mechanical Behavior of Materials","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46642843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract This study aims to investigate the adequacy of composite cellular beams with lightweight reinforced concrete deck slab as a structural unit for harmonic loaded buildings. The experimental program involved three fixed-ends supported beams throughout 2140 mm. Three concrete types were included: Normal Weight Concrete (NWC), Lightweight Aggregate Concrete (LWAC), and Lightweight Fiber Reinforced Aggregate Concrete (LWACF). The considered frequencies were (5, 10, 15, 20, 25, and 30) Hz. It was indicated that the harmonic load caused a significant influence on LWAC response (64% greater than NWC) and lattice cracks were observed, especially at 30 Hz. As for LWACF slab, no cracks appeared, and the harmonic load had a minor effect on the vibration amplitude. Adding fiber to LWAC improved its behavior and made the amplitude no more than 11.11%, corresponding to NWC. So, the response variance for the LWACF was approximately negligible compared with NWC. It is worth mentioning that the study produced a lightweight structure that resists harmonic vibrations with a small strength reduction by using LWACF as a deck-slab for cellular specimens and provides a structural element with a smaller density of about 27%, which presents an advantage for the cellular beam that is adopted for low-loaded structures.
{"title":"Response of composite steel-concrete cellular beams of different concrete deck types under harmonic loads","authors":"Zahraa Hussien Dakhela, S. D. Mohammed","doi":"10.1515/jmbm-2022-0014","DOIUrl":"https://doi.org/10.1515/jmbm-2022-0014","url":null,"abstract":"Abstract This study aims to investigate the adequacy of composite cellular beams with lightweight reinforced concrete deck slab as a structural unit for harmonic loaded buildings. The experimental program involved three fixed-ends supported beams throughout 2140 mm. Three concrete types were included: Normal Weight Concrete (NWC), Lightweight Aggregate Concrete (LWAC), and Lightweight Fiber Reinforced Aggregate Concrete (LWACF). The considered frequencies were (5, 10, 15, 20, 25, and 30) Hz. It was indicated that the harmonic load caused a significant influence on LWAC response (64% greater than NWC) and lattice cracks were observed, especially at 30 Hz. As for LWACF slab, no cracks appeared, and the harmonic load had a minor effect on the vibration amplitude. Adding fiber to LWAC improved its behavior and made the amplitude no more than 11.11%, corresponding to NWC. So, the response variance for the LWACF was approximately negligible compared with NWC. It is worth mentioning that the study produced a lightweight structure that resists harmonic vibrations with a small strength reduction by using LWACF as a deck-slab for cellular specimens and provides a structural element with a smaller density of about 27%, which presents an advantage for the cellular beam that is adopted for low-loaded structures.","PeriodicalId":17354,"journal":{"name":"Journal of the Mechanical Behavior of Materials","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49093609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Measurement of construction performance is essential to a clear image of the present situation. This monitoring by the management team is necessary to identify locations where performance is exceptionally excellent or poor and to identify the primary reasons so that the lessons gained may be exported to the firm and its progress strengthened. This research attempts to construct an integrated mathematical model utilizing one of the recent methodologies for dealing with the fuzzy representation of experts’ knowledge and judgment considering hesitancy called spherical fuzzy analytic hierarchy process (SFAHP) method to assess the contractor’s performance per the project performance parameters (cost, schedule, quality, leadership, and change management). At the same time, most project control systems are currently applied through software like Primavera P6 or MS Project. These look at a project’s cost and schedule status by following the earned value analysis for finding the performance. Based on decision makers’ preferences, the analytic hierarchy process (AHP) may be used to arrive at the optimum conclusion. AHP approaches are discussed, including AHP, grey-AHP, fuzzy-AHP, and SFAHP weights comparison. Calculation results showed that the spherical fuzzy approach differs significantly from the other approaches where it considers the decision maker’s hesitation when making linguistic multicriteria decisions and then, as a result, recommends applying periodically for performance measurement. This model can be viewed as a valuable way to help the decision-making stakeholders in the construction sector do the best job about critical issues at a suitable time.
{"title":"A spherical fuzzy AHP model for contractor assessment during project life cycle","authors":"Hayder Ghazi Abdulkareem, K. R. Erzaij","doi":"10.1515/jmbm-2022-0042","DOIUrl":"https://doi.org/10.1515/jmbm-2022-0042","url":null,"abstract":"Abstract Measurement of construction performance is essential to a clear image of the present situation. This monitoring by the management team is necessary to identify locations where performance is exceptionally excellent or poor and to identify the primary reasons so that the lessons gained may be exported to the firm and its progress strengthened. This research attempts to construct an integrated mathematical model utilizing one of the recent methodologies for dealing with the fuzzy representation of experts’ knowledge and judgment considering hesitancy called spherical fuzzy analytic hierarchy process (SFAHP) method to assess the contractor’s performance per the project performance parameters (cost, schedule, quality, leadership, and change management). At the same time, most project control systems are currently applied through software like Primavera P6 or MS Project. These look at a project’s cost and schedule status by following the earned value analysis for finding the performance. Based on decision makers’ preferences, the analytic hierarchy process (AHP) may be used to arrive at the optimum conclusion. AHP approaches are discussed, including AHP, grey-AHP, fuzzy-AHP, and SFAHP weights comparison. Calculation results showed that the spherical fuzzy approach differs significantly from the other approaches where it considers the decision maker’s hesitation when making linguistic multicriteria decisions and then, as a result, recommends applying periodically for performance measurement. This model can be viewed as a valuable way to help the decision-making stakeholders in the construction sector do the best job about critical issues at a suitable time.","PeriodicalId":17354,"journal":{"name":"Journal of the Mechanical Behavior of Materials","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46785973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Construction of shallow foundations on weak cohesive soils have limited load-bearing capacity and excessive vertical displacement. This may cause structural damage and reduce the structure’s durability. Traditionally, weak cohesive soils are excavated and replaced with another stronger material layer, or the foundation is enlarged. These procedures are costly and time-consuming. However, these soils are also difficult to stabilize due to their low permeability and slow consolidation. Therefore, it has become necessary to use geosynthetic material. In this study, a square footing model with an eccentric load was tested in geogrid-reinforced clay. The adopted load eccentricity ratios were 0.05 to 0.1, 0.16, and 0.25. Twenty-one tests were executed to estimate the reinforcement influence and eccentricity on the ultimate bearing capacity (UBC). The geogrid improved the BC by 2.27 and 2.12 times compared to unreinforced soil for centrical and eccentrical loads, respectively. The best first layer ratio and the best number of reinforcements were found to be 0.35 and 4. A new equation for BCR with knowing the number of reinforcing layers was proposed and compared with other studies’ outcomes. It was concluded that the foundation tilts in a linear relationship with eccentricity, with a smaller rate inside the core than outside.
{"title":"Ultimate bearing capacity of eccentrically loaded square footing over geogrid-reinforced cohesive soil","authors":"Hussam Aldeen J. Hassan, R. R. Shakir","doi":"10.1515/jmbm-2022-0035","DOIUrl":"https://doi.org/10.1515/jmbm-2022-0035","url":null,"abstract":"Abstract Construction of shallow foundations on weak cohesive soils have limited load-bearing capacity and excessive vertical displacement. This may cause structural damage and reduce the structure’s durability. Traditionally, weak cohesive soils are excavated and replaced with another stronger material layer, or the foundation is enlarged. These procedures are costly and time-consuming. However, these soils are also difficult to stabilize due to their low permeability and slow consolidation. Therefore, it has become necessary to use geosynthetic material. In this study, a square footing model with an eccentric load was tested in geogrid-reinforced clay. The adopted load eccentricity ratios were 0.05 to 0.1, 0.16, and 0.25. Twenty-one tests were executed to estimate the reinforcement influence and eccentricity on the ultimate bearing capacity (UBC). The geogrid improved the BC by 2.27 and 2.12 times compared to unreinforced soil for centrical and eccentrical loads, respectively. The best first layer ratio and the best number of reinforcements were found to be 0.35 and 4. A new equation for BCR with knowing the number of reinforcing layers was proposed and compared with other studies’ outcomes. It was concluded that the foundation tilts in a linear relationship with eccentricity, with a smaller rate inside the core than outside.","PeriodicalId":17354,"journal":{"name":"Journal of the Mechanical Behavior of Materials","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45265993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Serial tendering is better than other types of tendering when it comes to cost reduction, where civil infrastructure projects need a significant increase in the amount of tough planning, financial expenditures, engineering work, and resources of a different character than other types of construction projects. The effects of a lack of funding cause decrease in the completion speed of the project on time. The need to reduce the cost of bidding on recurrent civil infrastructure projects is critical. To achieve the desired goals of this research, this article will provide an overview of the type of bids used in the construction of schools implemented in the current financial perspective in Iraq, the extent of benefit, and the amount of possible reduction if continuous and serial tendering are used.
{"title":"Utilization of serial tendering to reduce the value project","authors":"Arshed Abbas Mohammed, K. R. Erzaij","doi":"10.1515/jmbm-2022-0034","DOIUrl":"https://doi.org/10.1515/jmbm-2022-0034","url":null,"abstract":"Abstract Serial tendering is better than other types of tendering when it comes to cost reduction, where civil infrastructure projects need a significant increase in the amount of tough planning, financial expenditures, engineering work, and resources of a different character than other types of construction projects. The effects of a lack of funding cause decrease in the completion speed of the project on time. The need to reduce the cost of bidding on recurrent civil infrastructure projects is critical. To achieve the desired goals of this research, this article will provide an overview of the type of bids used in the construction of schools implemented in the current financial perspective in Iraq, the extent of benefit, and the amount of possible reduction if continuous and serial tendering are used.","PeriodicalId":17354,"journal":{"name":"Journal of the Mechanical Behavior of Materials","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47012561","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}
P. Manik, Samuel Samuel, T. Tuswan, S. Jokosisworo, Rossy Kristia Nadapdap
Abstract With the increased emphasis on the need to use recyclable bio-based materials and a better understanding of the mechanical properties of laminated bamboo, there is currently a great deal of interest in developing a new generation of low-cost bamboo-based composites for use in fishing vessels. Laminated bamboo composites (LBCs) comprised of Apus bamboo (Gigantochloa apus) and fibreglass mats were investigated to obtain the mechanical characteristics. The LBC with 45°/−45° cross-fibre directions combined with chopped strand mat fibreglass was developed under different layers and mass fractions with the same composite thickness. The influence of different numbers of laminated bamboo layers (3–7 layers) on several mechanical testings, including impact tests using ASTM D256, bending tests using ASTM D7264, tensile tests using ASTM D3039, V-notched beam test using ASTM D7078, and lap shear tests using ASTM D5868 standard, were carried out. The result showed that the strategy in improving the strength properties of LBCs could be achieved by using a thinner bamboo lamina with a higher number of bamboo layers. It was found that bamboo composites with 7 layers with a higher epoxy mass matrix had superior mechanical properties than those with 3 and 5 layers at the same thickness. Another finding revealed that adding fibreglass mat to current LBCs improved mechanical properties compared to previous research, explicitly bending strength increased by about 4.02–7.56% and tensile strength in the range of 12.44–17.73%. It can be found that only specimen with 7 layers fulfils the Indonesian Bureau Classification’s bending and tensile strength threshold.
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