Successful people utilize their time judiciously. The challenge of completing construction projects within the estimated time frame is the biggest concern among practitioners. In this research two aspects have been highlighted, first; the most significant factor of time overrun in construction projects performed by Erbil Municipality during road construction. The second aspect is the time management methods held by the project team. A random sampling technique was used to administer 126 questionnaires to professionals such as Project managers, Engineers, and contractors working on road construction projects for Erbil municipality. On the other hand, a case study has been conducted for 70 constructed projects during 2018-2022 for the evaluation of time management techniques in road construction projects by identifying the process of monitoring, software packages that are used for that, the progress of work, and investigating how progress records are kept in Erbil City municipality projects. The results revealed that the most significant factor for time overrun was the economic crisis which led to the failure to pay contractors' dues in a timely manner, followed by the unreasonable time frame for the completion of projects. Used techniques and software packages for time management were identified It is revealed that there is no specific method for managing time. Multiple methods are used depending on the situation.
{"title":"EVALUATION OF TIME OVERRUNS AND TIME MANAGEMENT TECHNIQUES IN ROAD CONSTRUCTION PROJECTS IN ERBIL CITY","authors":"Aksana Jihad Mohammed","doi":"10.31272/jeasd.27.4.7","DOIUrl":"https://doi.org/10.31272/jeasd.27.4.7","url":null,"abstract":"Successful people utilize their time judiciously. The challenge of completing construction projects within the estimated time frame is the biggest concern among practitioners. In this research two aspects have been highlighted, first; the most significant factor of time overrun in construction projects performed by Erbil Municipality during road construction. The second aspect is the time management methods held by the project team. A random sampling technique was used to administer 126 questionnaires to professionals such as Project managers, Engineers, and contractors working on road construction projects for Erbil municipality. On the other hand, a case study has been conducted for 70 constructed projects during 2018-2022 for the evaluation of time management techniques in road construction projects by identifying the process of monitoring, software packages that are used for that, the progress of work, and investigating how progress records are kept in Erbil City municipality projects. The results revealed that the most significant factor for time overrun was the economic crisis which led to the failure to pay contractors' dues in a timely manner, followed by the unreasonable time frame for the completion of projects. Used techniques and software packages for time management were identified It is revealed that there is no specific method for managing time. Multiple methods are used depending on the situation.","PeriodicalId":33282,"journal":{"name":"Journal of Engineering and Sustainable Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47381471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The usage of polymer-modified asphalt binders has increased as a result of the significant increase in the number of conventional cars operating on Iraqi roads in recent years. This has resulted in increased strains being placed on pavement structures and materials. Global exploration has focused on the development of stabilizing Stone Mastic Asphalt mixtures for improved pavement behavior. Numerous effective efforts were made to stabilize stone mastic asphalt mixes with polymers and fibers. Iraq produces a considerable amount of waste polymer materials each year. Usually, they are sent to landfills for disposal. These wastes are dumped, occupying a sizable portion of landfill space and creating various serious environmental issues. The study focuses on how waste polymer additions, such as recycled plastic bottles, shopping boxes, and tire crumb rubber, affect the mechanical performance and durability of stone mastic asphalt mixtures. The mechanical performance attributes were assessed. It is evident from the findings that the drain-down amounts were within the permissible requirement range. The findings also showed that the indirect tensile strength, Marshall Stability, moisture damage resistance, and resistance for permanent deformation of stone mastic asphalt mixtures have all increased as a result of the use of waste polymer components. The recycled polymer-modified mixes are the combinations that are most resistant to rutting, according to the results of the repeated load axial creep tests. Iraq may have new options to employ the significant volumes of recycled polymers that are becoming accessible as a result of recycling waste polymers.
{"title":"INVESTIGATION OF THE MECHANICAL PERFORMANCE OF STONE MASTIC ASPHALT MIXTURES MODIFIED BY RECYCLED WASTE POLYMERS","authors":"S. Tayh, Doua Yousif Khalif Khalif","doi":"10.31272/jeasd.27.4.2","DOIUrl":"https://doi.org/10.31272/jeasd.27.4.2","url":null,"abstract":"The usage of polymer-modified asphalt binders has increased as a result of the significant increase in the number of conventional cars operating on Iraqi roads in recent years. This has resulted in increased strains being placed on pavement structures and materials. Global exploration has focused on the development of stabilizing Stone Mastic Asphalt mixtures for improved pavement behavior. Numerous effective efforts were made to stabilize stone mastic asphalt mixes with polymers and fibers. Iraq produces a considerable amount of waste polymer materials each year. Usually, they are sent to landfills for disposal. These wastes are dumped, occupying a sizable portion of landfill space and creating various serious environmental issues. The study focuses on how waste polymer additions, such as recycled plastic bottles, shopping boxes, and tire crumb rubber, affect the mechanical performance and durability of stone mastic asphalt mixtures. The mechanical performance attributes were assessed. It is evident from the findings that the drain-down amounts were within the permissible requirement range. The findings also showed that the indirect tensile strength, Marshall Stability, moisture damage resistance, and resistance for permanent deformation of stone mastic asphalt mixtures have all increased as a result of the use of waste polymer components. The recycled polymer-modified mixes are the combinations that are most resistant to rutting, according to the results of the repeated load axial creep tests. Iraq may have new options to employ the significant volumes of recycled polymers that are becoming accessible as a result of recycling waste polymers.","PeriodicalId":33282,"journal":{"name":"Journal of Engineering and Sustainable Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45786435","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}
Asphalt concrete is widely known to be a self-healing material, by repeated loading the micro-cracks have appearing and disappeared when both faces of a fissure touch. This process is applied until the crack is completely gone and the material regains its prior resistance. In this study, two strategies are presented to boost of healing rate and applied in porous asphalt, one of them is induction heating. This method is used by mixing 1.1% of steel wool fiber to speed up this phenome, with 20mm aggregate size for porous asphalt mixture and 21% air voids content. Another approach is self-healing by 0.5% encapsulated agents using. These capsulate are incorporated within the asphalt mixture, then the capsules break when subjected to repeating loading on the asphalt surface. It has been discovered that there is a moment in the lifespan of an asphalt road where the capsules or induction heating applied can successfully self-heal the existing crack damage.
{"title":"MICROCAPSULES AND INDUCTION HEATING: TWO METHODS FOR CLOSING CRACKS IN ASPHALT POROUS PAVEMENTS","authors":"Siham Idan Salih, Alvaro Garcia, J. Contreras,","doi":"10.31272/jeasd.27.4.3","DOIUrl":"https://doi.org/10.31272/jeasd.27.4.3","url":null,"abstract":"Asphalt concrete is widely known to be a self-healing material, by repeated loading the micro-cracks have appearing and disappeared when both faces of a fissure touch. This process is applied until the crack is completely gone and the material regains its prior resistance. In this study, two strategies are presented to boost of healing rate and applied in porous asphalt, one of them is induction heating. This method is used by mixing 1.1% of steel wool fiber to speed up this phenome, with 20mm aggregate size for porous asphalt mixture and 21% air voids content. Another approach is self-healing by 0.5% encapsulated agents using. These capsulate are incorporated within the asphalt mixture, then the capsules break when subjected to repeating loading on the asphalt surface. It has been discovered that there is a moment in the lifespan of an asphalt road where the capsules or induction heating applied can successfully self-heal the existing crack damage.","PeriodicalId":33282,"journal":{"name":"Journal of Engineering and Sustainable Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46943305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The current research is dedicated to studying the flexural behavior of composite box beams with corroded bottom flanges. Six simply supported beam specimens were manufactured and tested. The composite box beams were fabricated with steel box beams of 1100mm, 100mm, and 100mm for length, width, and height, respectively, while the concrete deck slabs were made with dimensions of 1100mm, 400mm, and 50mm for length, width, and thickness, respectively. The composite sections were formed by connecting the RC deck slabs with the steel box beams by using a headed shear connector. Three main variables were considered; the load type (monotonic or repeated), bottom flange thickness (with or without corrosion), and whether to consider or ignore the strengthening by CFRP strip. Experimental results indicated that the ultimate loads were decreased by 29-33% for the corroded bottom flange beam specimens; while the ultimate loads for the strengthened beam specimens were increased by 60-67% as compared with the un-strengthened corroded corresponding beam specimens. Also, the change of the applied loads from monotonic to repeated leads to a reduction of the ultimate load by 17-22%.
{"title":"STRUCTURAL PERFORMANCE OF COMPOSITE BOX BEAMS WITH CORRODED BOTTOM FLANGE UNDER MONOTONIC AND REPEATED LOADS","authors":"Ghufran Khudair Abbass, Ali Hameed Aziz","doi":"10.31272/jeasd.27.4.10","DOIUrl":"https://doi.org/10.31272/jeasd.27.4.10","url":null,"abstract":"The current research is dedicated to studying the flexural behavior of composite box beams with corroded bottom flanges. Six simply supported beam specimens were manufactured and tested. The composite box beams were fabricated with steel box beams of 1100mm, 100mm, and 100mm for length, width, and height, respectively, while the concrete deck slabs were made with dimensions of 1100mm, 400mm, and 50mm for length, width, and thickness, respectively. The composite sections were formed by connecting the RC deck slabs with the steel box beams by using a headed shear connector. Three main variables were considered; the load type (monotonic or repeated), bottom flange thickness (with or without corrosion), and whether to consider or ignore the strengthening by CFRP strip. Experimental results indicated that the ultimate loads were decreased by 29-33% for the corroded bottom flange beam specimens; while the ultimate loads for the strengthened beam specimens were increased by 60-67% as compared with the un-strengthened corroded corresponding beam specimens. Also, the change of the applied loads from monotonic to repeated leads to a reduction of the ultimate load by 17-22%.","PeriodicalId":33282,"journal":{"name":"Journal of Engineering and Sustainable Development","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69348986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The problem of computing the set of prime implicants to represent a Boolean function is a classical problem that is still considered a running problem for research because all known approaches have limitations. The article reviews existing methods for computing prime implicants and highlights their limitations, particularly for multi-output functions and limited scalability due to the growth in memory required to complete the computation. Then it proposes a recursive ternary-based minimization algorithm to compute the prime implicants of multi-output Boolean functions. The algorithm is based on the concept of Programmable Logic Array (PLA) tables, which provide a structured and efficient representation of Boolean functions. The algorithm takes advantage of the ternary logic system to efficiently compute the prime implicants while maintaining scalability for large and complex functions, which has significant implications for digital circuit design and optimization.
{"title":"RECURSIVE TERNARY-BASED ALGORITHM FOR COMPUTING PRIME IMPLICANTS OF MULTI-OUTPUT BOOLEAN FUNCTIONS","authors":"Zaid Al-Wardi, Osama Al-Wardi","doi":"10.31272/jeasd.27.3.2","DOIUrl":"https://doi.org/10.31272/jeasd.27.3.2","url":null,"abstract":"The problem of computing the set of prime implicants to represent a Boolean function is a classical problem that is still considered a running problem for research because all known approaches have limitations. The article reviews existing methods for computing prime implicants and highlights their limitations, particularly for multi-output functions and limited scalability due to the growth in memory required to complete the computation. Then it proposes a recursive ternary-based minimization algorithm to compute the prime implicants of multi-output Boolean functions. The algorithm is based on the concept of Programmable Logic Array (PLA) tables, which provide a structured and efficient representation of Boolean functions. The algorithm takes advantage of the ternary logic system to efficiently compute the prime implicants while maintaining scalability for large and complex functions, which has significant implications for digital circuit design and optimization.","PeriodicalId":33282,"journal":{"name":"Journal of Engineering and Sustainable Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47003530","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}
With the rapid development of wireless communication, 5G is gradually growing into a large-scale basic Internet that supports various industries in the whole society. The substantial expansion of its service scope poses many challenges for the underlying technology, especially for the crucial component of the physical Layer-Orthogonal Frequency Division Multiplexing (OFDM). Recently, Neural Networks (NNs) have attracted extensive attention due to their excellent performance in computing vision and natural language processing. Its strong universality also provides new development space for traditional communications. This manuscript conducts an in-depth study on channel estimation for OFDM systems and explores the possible application of a Generalized Regression Neural Network (GRNN) to estimate the Channel Impulse Response (CIR) attenuated by AWGN and Rayleigh fading system. Moreover, three traditional channel estimation algorithms, i.e., LS, MMSE, and LMMSE, are derived by mathematics. In addition, this thesis illustrates several typical neural networks in detail, including their internal structure, parameter updating process, and related optimization algorithms.
{"title":"RAYLEIGH FADING CHANNEL ESTIMATION BASED ON GENERALIZED REGRESSION NEURAL NETWORK","authors":"Emad Ahmed Hussien, Ghanim Abdulkareem","doi":"10.31272/jeasd.27.3.6","DOIUrl":"https://doi.org/10.31272/jeasd.27.3.6","url":null,"abstract":"With the rapid development of wireless communication, 5G is gradually growing into a large-scale basic Internet that supports various industries in the whole society. The substantial expansion of its service scope poses many challenges for the underlying technology, especially for the crucial component of the physical Layer-Orthogonal Frequency Division Multiplexing (OFDM). Recently, Neural Networks (NNs) have attracted extensive attention due to their excellent performance in computing vision and natural language processing. Its strong universality also provides new development space for traditional communications. This manuscript conducts an in-depth study on channel estimation for OFDM systems and explores the possible application of a Generalized Regression Neural Network (GRNN) to estimate the Channel Impulse Response (CIR) attenuated by AWGN and Rayleigh fading system. Moreover, three traditional channel estimation algorithms, i.e., LS, MMSE, and LMMSE, are derived by mathematics. In addition, this thesis illustrates several typical neural networks in detail, including their internal structure, parameter updating process, and related optimization algorithms.","PeriodicalId":33282,"journal":{"name":"Journal of Engineering and Sustainable Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43727568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The control of (PMSM) is the subject of this study and the torque ripple reduction in (PMSM) is the main goal of this work. Torque and flux are controlled using a predictive model and Vector Control. Because it is commonly employed in regulating electric motors. Space vector control and predictive control are two (PMSM) control approaches used in this study. Predictive control was determined to be more effective in terms of response and action after a Matlab simulation of the two approaches. MPC covers all potential switching states that decrease actual torque and flux ripples as well as Total Harmonic Distortion. The benefits of MPC include simple principles, an easy-to-use console, and the ability to implement limits quickly. However, there are some drawbacks to this technique, including the requirement for bigger accounts and faster machines. The fundamental principles of the control techniques discussed are provided A (PMSM) powered by a two-level power converter is then used to simulate the control approaches. Their performance in comparison is based on the obtained results.
{"title":"PERMANENT MAGNET SYNCHRONOUS MOTOR TORQUE RIPPLE REDUCTION USING PREDICTIVE TORQUE CONTROL","authors":"Saif T. Bahar, Riyadh Ghanem Omar","doi":"10.31272/jeasd.27.3.9","DOIUrl":"https://doi.org/10.31272/jeasd.27.3.9","url":null,"abstract":"The control of (PMSM) is the subject of this study and the torque ripple reduction in (PMSM) is the main goal of this work. Torque and flux are controlled using a predictive model and Vector Control. Because it is commonly employed in regulating electric motors. Space vector control and predictive control are two (PMSM) control approaches used in this study. Predictive control was determined to be more effective in terms of response and action after a Matlab simulation of the two approaches. MPC covers all potential switching states that decrease actual torque and flux ripples as well as Total Harmonic Distortion. The benefits of MPC include simple principles, an easy-to-use console, and the ability to implement limits quickly. However, there are some drawbacks to this technique, including the requirement for bigger accounts and faster machines. The fundamental principles of the control techniques discussed are provided A (PMSM) powered by a two-level power converter is then used to simulate the control approaches. Their performance in comparison is based on the obtained results.","PeriodicalId":33282,"journal":{"name":"Journal of Engineering and Sustainable Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46617355","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}
S. AL-khyat, D. Naji, Huda T. Hamad, Helen Onyeaka
Soil contamination produced by improper management of various petroleum and industrial products causes potential risks to the environment and soil engineering properties. Such contamination causes environmental deterioration and adversely affects soil engineering performance, altering almost all geotechnical properties. Several remediation techniques have been proposed to decontaminate the polluted soils. Choosing the best technique depends on both the energy consumption during operation and the treatment efficiency. The lack of a universally appropriate treatment method and the unavoidable expansion of contaminated land have justified the sake of reviewing the behavior of contaminated soils to develop both environmentally and geotechnically suitable soils for construction projects. The present paper reviewed some soil contamination sources’ backgrounds, effects, and remediation methods. Soils influenced by petroleum hydrocarbons and industrial effluents were evaluated. According to the reviewed studies, contaminants are evidenced to have a negative impact on soils' geotechnical characteristics by increasing settlement and swelling, reducing shear strength, and decreasing permeability. The need to restore the engineering characteristics of soils suggest the necessity to use remediation or stabilization technique. The electrochemical method, bioremediation, and stabilizing by additives are revealed to be efficient in improving the engineering properties and performance of contaminated soils.
{"title":"A REVIEW ON SOIL CONTAMINATION SOURCES: IMPACT ON ENGINEERING PROPERTIES AND REMEDIATION TECHNIQUES","authors":"S. AL-khyat, D. Naji, Huda T. Hamad, Helen Onyeaka","doi":"10.31272/jeasd.27.3.1","DOIUrl":"https://doi.org/10.31272/jeasd.27.3.1","url":null,"abstract":"Soil contamination produced by improper management of various petroleum and industrial products causes potential risks to the environment and soil engineering properties. Such contamination causes environmental deterioration and adversely affects soil engineering performance, altering almost all geotechnical properties. Several remediation techniques have been proposed to decontaminate the polluted soils. Choosing the best technique depends on both the energy consumption during operation and the treatment efficiency. The lack of a universally appropriate treatment method and the unavoidable expansion of contaminated land have justified the sake of reviewing the behavior of contaminated soils to develop both environmentally and geotechnically suitable soils for construction projects. The present paper reviewed some soil contamination sources’ backgrounds, effects, and remediation methods. Soils influenced by petroleum hydrocarbons and industrial effluents were evaluated. According to the reviewed studies, contaminants are evidenced to have a negative impact on soils' geotechnical characteristics by increasing settlement and swelling, reducing shear strength, and decreasing permeability. The need to restore the engineering characteristics of soils suggest the necessity to use remediation or stabilization technique. The electrochemical method, bioremediation, and stabilizing by additives are revealed to be efficient in improving the engineering properties and performance of contaminated soils.","PeriodicalId":33282,"journal":{"name":"Journal of Engineering and Sustainable Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47266918","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}
For several decades, calcium chloride has been widely used as a cheap and effective accelerator. Calcium chloride is remarkably decreasing the initial and final setting times of concrete. It is mainly used at low-temperature concreting because it allows for earlier finishing and reduces the effects of water freezing inside fresh concrete. The use of calcium chloride in reinforced concrete has been decreased after identifying its effect on reinforcement corrosion. However, calcium chloride is still widely used in ordinary concrete and some reinforced concrete in specific proportions. This paper reviews the most important mechanical and chemical effects of calcium chloride on concrete mixtures, its effects on reinforcement corrosion, the conditions of its use, and its mechanism of action. This review study highlights the need for a detailed study to verify calcium chloride’s exact role in reinforcement corrosion and the maximum permissible limits for its use in reinforced concrete. In addition, there is a need to study the compatibility of calcium chloride with other concrete admixtures.
{"title":"A REVIEW STUDY OF THE USE OF CALCIUM CHLORIDE IN CONCRETE","authors":"Haitham Saeed","doi":"10.31272/jeasd.27.3.4","DOIUrl":"https://doi.org/10.31272/jeasd.27.3.4","url":null,"abstract":"For several decades, calcium chloride has been widely used as a cheap and effective accelerator. Calcium chloride is remarkably decreasing the initial and final setting times of concrete. It is mainly used at low-temperature concreting because it allows for earlier finishing and reduces the effects of water freezing inside fresh concrete. The use of calcium chloride in reinforced concrete has been decreased after identifying its effect on reinforcement corrosion. However, calcium chloride is still widely used in ordinary concrete and some reinforced concrete in specific proportions. This paper reviews the most important mechanical and chemical effects of calcium chloride on concrete mixtures, its effects on reinforcement corrosion, the conditions of its use, and its mechanism of action. This review study highlights the need for a detailed study to verify calcium chloride’s exact role in reinforcement corrosion and the maximum permissible limits for its use in reinforced concrete. In addition, there is a need to study the compatibility of calcium chloride with other concrete admixtures.","PeriodicalId":33282,"journal":{"name":"Journal of Engineering and Sustainable Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46124298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The influence of friction pressure on welding quality when friction stud welding 1017 low carbon steel with AISI 304 austenitic stainless steel is investigated in this study. friction stud welding is employed in industrial applications instead of conventional welding processes Due to the friction welding process didn't need to reach the melting point of welded metals. Welding is performed on these dissimilar metals by utilizing a lathe machine with a load cell connected to a weight indicator and a manufacturing grip to fasten the plate at a rotating speed of 1600 RPM, a friction time of 20 seconds, and a friction pressure of (15, 20, and 25) MPa. After the welding procedure is completed, the specimens are subjected to tensile, torque, and hardness tests to evaluate the welding quality. In addition, optical microscope research was carried out to determine the microstructural aspects. The effect of friction pressure on welding quality was investigated based on the information generated from the results. The increase of friction pressure during the process from 15 MPa to 25 MPa leads to an increasing ultimate tensile strength from 203 MPa to 210 MPa approximately. Also, the torque values raised from 179 N.m to 198 N.m in the same case.
{"title":"INVESTIGATION OF FRICTION PRESSURE EFFECT ON WELDING QUALITY IN FRICTION STUD WELDING PROCESS","authors":"Mustafa Saad Kadhim, K. K. Resan","doi":"10.31272/jeasd.27.3.8","DOIUrl":"https://doi.org/10.31272/jeasd.27.3.8","url":null,"abstract":"The influence of friction pressure on welding quality when friction stud welding 1017 low carbon steel with AISI 304 austenitic stainless steel is investigated in this study. friction stud welding is employed in industrial applications instead of conventional welding processes Due to the friction welding process didn't need to reach the melting point of welded metals. Welding is performed on these dissimilar metals by utilizing a lathe machine with a load cell connected to a weight indicator and a manufacturing grip to fasten the plate at a rotating speed of 1600 RPM, a friction time of 20 seconds, and a friction pressure of (15, 20, and 25) MPa. After the welding procedure is completed, the specimens are subjected to tensile, torque, and hardness tests to evaluate the welding quality. In addition, optical microscope research was carried out to determine the microstructural aspects. The effect of friction pressure on welding quality was investigated based on the information generated from the results. The increase of friction pressure during the process from 15 MPa to 25 MPa leads to an increasing ultimate tensile strength from 203 MPa to 210 MPa approximately. Also, the torque values raised from 179 N.m to 198 N.m in the same case.","PeriodicalId":33282,"journal":{"name":"Journal of Engineering and Sustainable Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46553888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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