Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 56 5 2024 07 22 Laboratory investigation of the effect of plastic packaging belt fibers and iron oxide on the mechanical properties of self-compacting concrete Laboratory investigation of the effect of plastic packaging belt fibers and iron oxide on the mechanical properties of self-compacting concrete 517 550 5409 10.22060/ceej.2024.23070.8099 FA Amir Hossein Derakhshan Nezhad Master's student in Civil-Structural Engineering, Technical and Engineering Faculty, Behbahan Khatam Alanbia University of Technology, Behbahan, Iran. 0009-0008-0994-8590 Mahbobeh Mirzaie Aliabadi Assistant Professor, Technical and Engineering Faculty, Behbahan Khatam Alanbia University of Technology, Behbahan, Iran. Mohammad Sadegh Shahidzadeh Assistant Professor, Technical and Engineering Faculty, Behbahan Khatam Alanbia University of Technology, Behbahan, Iran. Journal Article 2024 03 20 Self-compacting concrete is one of the newest types of concrete due to its durability, efficiency, viscosity, stability, flowability, and resistance. Nowadays, one of the most important concerns in the environment is solid waste disposal. Plastic packaging belts are one of the plastic materials that are thrown away after use and are known as waste, also iron smelting factories are the main source of iron oxide waste production. This research is based on the idea of using plastic packing belts and iron oxide waste in the design of self-compacting concrete mix with different percentages (0, 0.5, 1, 1.5, 2 percent compared to the weight of cement) and ( 0, 5, 10, 15, 20% relative to the weight of sand) was added as an additive. For fresh and hardened properties of self-compacting concrete tests with and without fibers and iron oxide, slump flow tests, V funnel, L box, J ring, U box and compressive strength, tensile strength, ultrasonic pulse speed, Schmidt hammer, temperature effect They were evaluated on compressive strength and permeability. The results of the tests showed that with the increase in the percentage of fibers and iron oxide waste in self-compacting concrete for cubic samples, respectively, the compressive strength, ultrasonic pulse speed, Schmidt hammer and the effect of temperature on the 1-day compressive strength in 28-day processing from the range of 1.61% - 72.57%, 10% - 57.5%, 3.27% - 9.27% and 5.22 – 20.64% increased compared to self-compacting concrete (control) and also the tensile strength of cylindrical samples in 28 days processing. It increased from the range of 21.09%-72.57% compared to self-density (control). Self-compacting concrete is one of the newest types of concrete due to its durability, efficiency, viscosity, stability, flowability, and resistance. Nowadays, one of the most important concerns in the environment is solid waste disposal. Plastic packaging belts are one of the plastic materials that are thrown away after use and are known as waste, also iron smelting factories are the main source of iron oxide waste production. This research is based on the idea of using plastic packing belts and iron oxide waste in the design of self-compacting concrete mix with different percentages (0, 0.5, 1, 1.5, 2 percent compared to the weight of cement) and ( 0, 5, 10, 15, 20% relative to the weight of sand) was added as an additive. For fresh and hardened properties of self-compacting concrete tests with and without fibers and iron oxide, slump flow tests, V funnel, L box, J ring, U box and compressive strength, tensile strength, ultrasonic pulse speed, Schmidt hammer, temperature effect They were evaluated on compressive strength and permeability. The results of the tests showed that with the increase in the percentage of fibers and iron oxide waste in self-compacting concrete for cubic samples, respectively, the compressive strength, ultrasonic pulse speed, Schmidt hammer and the effect of temperature on the 1-day compressive strength in 28-day processing from the range of 1.61% - 72.57%, 10% - 57.5%, 3.27% - 9.27% and 5.22 – 20.64% increased compared to self-compacting concrete (control) and also the tensile strength of cylindrical samples in 28 days processing. It increased from the range of 21.09%-72.57% compared to self-density (control).

https://ceej.aut.ac.ir/article_5409_0ec7871afff20c4c9e8be8e6380d197b.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 56 5 2024 07 22 An Experimental Analysis of the Impact of the Transverse Distance of Cubic Obstacles on the Hydraulic Characteristics of Transverse Waves in Staggered Arrangements An Experimental Analysis of the Impact of the Transverse Distance of Cubic Obstacles on the Hydraulic Characteristics of Transverse Waves in Staggered Arrangements 551 568 5410 10.22060/ceej.2024.22137.7913 FA Kimiya Kamaei Department of Water Structures, Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran Mehdi Ghomeshi Department of Water Structures, Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran 0000-0002-8361-1645 Mehdi Daryaee Department of Water Structures, Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran Seyed Mahmoud Kashefipour Department of Water Structures, Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran Journal Article 2023 01 29 Transverse waves are formed by obstacles such as vegetation, bridge piers, and docks in the flow path. the present study investigated the effect of the transversal distance of cubic obstacles on the hydraulic characterization of transverse waves with four-wave modes in resonance. The obstacles were arranged staggered at two transversal distances and a constant longitudinal distance. All experiments were performed in a flume with a length of 16 m, a width of 1.25 m, and a height of 0.6 m. The flow discharge was varied between 30 and 38 lit/s in the experiments. The results showed that the flow regime was turbulent and sub-critical in experiments. In resonance, the Obstacle Reynolds Number and Froude Number were within the range of 2319<Re<5627 and 0.055<Fr<0.210 respectively. In resonance, the relative amplitude of the wave increases by increasing the transversal distance of obstacles (decreasing the density of obstacles), and the highest relative amplitude of 33% was obtained for T/D=9.6, wave mode IV, and Q=30 lit/s. With the increase in discharge, the relative amplitude of the wave in each transversal distance and all four wave modes decreased. Transverse waves are formed by obstacles such as vegetation, bridge piers, and docks in the flow path. the present study investigated the effect of the transversal distance of cubic obstacles on the hydraulic characterization of transverse waves with four-wave modes in resonance. The obstacles were arranged staggered at two transversal distances and a constant longitudinal distance. All experiments were performed in a flume with a length of 16 m, a width of 1.25 m, and a height of 0.6 m. The flow discharge was varied between 30 and 38 lit/s in the experiments. The results showed that the flow regime was turbulent and sub-critical in experiments. In resonance, the Obstacle Reynolds Number and Froude Number were within the range of 2319<Re<5627 and 0.055<Fr<0.210 respectively. In resonance, the relative amplitude of the wave increases by increasing the transversal distance of obstacles (decreasing the density of obstacles), and the highest relative amplitude of 33% was obtained for T/D=9.6, wave mode IV, and Q=30 lit/s. With the increase in discharge, the relative amplitude of the wave in each transversal distance and all four wave modes decreased.

https://ceej.aut.ac.ir/article_5410_a36ad7be52d47b37a1ca400db1d4d9ad.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 56 5 2024 07 22 Evaluating the Capacity of the Multi-Plate Mechanical Anchors in Granular Soils Evaluating the Capacity of the Multi-Plate Mechanical Anchors in Granular Soils 569 588 5420 10.22060/ceej.2024.22361.7958 FA Hamid Reza Mohammadkhanifard B.Sc., M.Sc., Department of Civil Engineering, Faculty of Civil Engineering and Earth Resources, Islamic Azad University, Central Tehran Branch, Tehran, Iran, Amir Ali Zad Department of Civil Engineering, , Islamic Azad University, Central Tehran Branch Mahsa Amjadi B.Sc., M.Sc., Department of Civil Engineering, Faculty of Civil Engineering and Earth Resources, Islamic Azad University, Central Tehran Branch, Tehran, Iran, Journal Article 2023 04 28 Nowadays, humans have thought of creating structures and platforms onshore and offshore to provide energy. Until now, various anchors with different shapes have been introduced for strength and stability of platforms, for offshore and onshore applications. In this research, a new type of expendable multi-plate anchors is proposed with the ability to expand the plates in the soil with lower energy. As these anchors are recently introduced, their bearing capacity has not been extensively evaluated. In this research, the behavior of these anchors was investigated experimentally. The evaluated parameters are soil compaction and distance between plates on the maximum pull-out capacity of them. Firstly the performance of single plate anchors was compared with the double plate anchors with equivalent areas then the effect of above mentioned parameters was determined for double plate anchors Based on the experimental results, single-plate shows higher bearing capacity in high soil compaction, but in low soil compaction, the bearing capacity of the double plate capacity is increased. The effect of the distance between the plates on the final bearing capacity has been far greater than the effect of the change in soil density. Also, 4 different soil compaction and distance between two plates for a double plate were investigated. Overall the effects of distance between two plates have more impact on bearing capacity in comparison to soil compaction Nowadays, humans have thought of creating structures and platforms onshore and offshore to provide energy. Until now, various anchors with different shapes have been introduced for strength and stability of platforms, for offshore and onshore applications. In this research, a new type of expendable multi-plate anchors is proposed with the ability to expand the plates in the soil with lower energy. As these anchors are recently introduced, their bearing capacity has not been extensively evaluated. In this research, the behavior of these anchors was investigated experimentally. The evaluated parameters are soil compaction and distance between plates on the maximum pull-out capacity of them. Firstly the performance of single plate anchors was compared with the double plate anchors with equivalent areas then the effect of above mentioned parameters was determined for double plate anchors Based on the experimental results, single-plate shows higher bearing capacity in high soil compaction, but in low soil compaction, the bearing capacity of the double plate capacity is increased. The effect of the distance between the plates on the final bearing capacity has been far greater than the effect of the change in soil density. Also, 4 different soil compaction and distance between two plates for a double plate were investigated. Overall the effects of distance between two plates have more impact on bearing capacity in comparison to soil compaction

https://ceej.aut.ac.ir/article_5420_afcd7211d1a05d729c13b28efbc8e45b.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 56 5 2024 07 22 Dimension reduction of the remote sensing data to estimate soil organic carbon Dimension reduction of the remote sensing data to estimate soil organic carbon 589 606 5434 10.22060/ceej.2024.22053.7890 FA Niusha Mozafari Department of Geodesy and Surveying Engineering, Tafresh University, Tafresh, Iran Hadiseh Sadat Hasani Department of Geodesy and Surveying Engineering, Tafresh University, Tafresh, Iran Marzieh Jafari Department of Geodesy and Surveying Engineering, Tafresh University, Tafresh, Iran Journal Article 2022 12 25 Soil is a very complex phenomenon that includes organic materials, minerals, water, and air. The distribution of organic matter in the soil has a profound effect on biological activity, nutrient availability, soil and soil seed structure, and water holding capacity, and soil management in general. In this research, the relation between soil spectral reflectance using the Landsat 8 satellite data as well as the SRTM Elevation data and soil organic carbon has been investigated. In the proposed method, spectral reflection of data in the main bands of the Landsat 8 satellite is investigated and processed. In addition to the main bands, vegetation and lighting indices, and topographic features have been studied. In this study, a method for selecting effective indexes in increasing the accuracy of soil organic carbon modeling is presented. For this purpose, in the first step of modeling, Linear regression, Support Vector Machine regression, and Neural Network methods have been used for the connection between remote sensing data and soil organic carbon. To implement the proposed method, 100 soil samples in East Azerbaijan province have been used. According to RMSE and R2 statistical indices, which are the basis for evaluating the models, the neural network model was selected as the final model, and with the values of RMSE = 0.404, R2= 0.254, and RRMSE=46.597 is more accurate than the regression method. Due to the importance of dimensionality to increase accuracy and reduce the complexity of calculations, a genetic algorithm was proposed in this study. This efficient algorithm increases the accuracy of soil organic carbon modeling and eliminates additional indicators. After applying the genetic algorithm (GA) to the neural network model, we were able to achieve better accuracy, and the values of the baseline statistical indices were changed to RMSE = 0.279, R2 = 0.718, and RRMSE=27.116. Also, to check the efficiency of the genetic algorithm, the PCA algorithm was also implemented on the data and the comparison results showed that the genetic algorithm was successful in reducing dimensions along with increasing accuracy. Soil is a very complex phenomenon that includes organic materials, minerals, water, and air. The distribution of organic matter in the soil has a profound effect on biological activity, nutrient availability, soil and soil seed structure, and water holding capacity, and soil management in general. In this research, the relation between soil spectral reflectance using the Landsat 8 satellite data as well as the SRTM Elevation data and soil organic carbon has been investigated. In the proposed method, spectral reflection of data in the main bands of the Landsat 8 satellite is investigated and processed. In addition to the main bands, vegetation and lighting indices, and topographic features have been studied. In this study, a method for selecting effective indexes in increasing the accuracy of soil organic carbon modeling is presented. For this purpose, in the first step of modeling, Linear regression, Support Vector Machine regression, and Neural Network methods have been used for the connection between remote sensing data and soil organic carbon. To implement the proposed method, 100 soil samples in East Azerbaijan province have been used. According to RMSE and R2 statistical indices, which are the basis for evaluating the models, the neural network model was selected as the final model, and with the values of RMSE = 0.404, R2= 0.254, and RRMSE=46.597 is more accurate than the regression method. Due to the importance of dimensionality to increase accuracy and reduce the complexity of calculations, a genetic algorithm was proposed in this study. This efficient algorithm increases the accuracy of soil organic carbon modeling and eliminates additional indicators. After applying the genetic algorithm (GA) to the neural network model, we were able to achieve better accuracy, and the values of the baseline statistical indices were changed to RMSE = 0.279, R2 = 0.718, and RRMSE=27.116. Also, to check the efficiency of the genetic algorithm, the PCA algorithm was also implemented on the data and the comparison results showed that the genetic algorithm was successful in reducing dimensions along with increasing accuracy.

https://ceej.aut.ac.ir/article_5434_0fe3094d8b20b823420cc3ee78c9e0b1.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 56 5 2024 07 22 Flowsheet development for low-grade manganese ores by physical and physicochemical methods Flowsheet development for low-grade manganese ores by physical and physicochemical methods 607 628 5435 10.22060/ceej.2024.22479.7979 FA Shima Rahimi Amirkabir University of Technology, Department of Mining Engineering, Tehran, Iran. Mehdi Irannajad Amirkabir University of Technology Akbar Mehdilo Faculty of Engineering University of Mohaghegh Ardabili Ardabil Iran Journal Article 2023 06 12 In this research, to achieve an appropriate flowsheet for the processing of low-grade manganese ore, some kinds of beneficiation methods have been investigated and compared. The used ore sample contains an average grade of 13.8% MnO. The valuable mineral containing manganese is pyrolusite, and calcite is the main gangue mineral in the ore. Gravity (jigging and tabling), high-intensity magnetic, and flotation (cationic and anionic) methods were examined in this study. Among the applied methods, cationic flotation has the highest manganese recovery in the concentrate (77.4%) with a selectivity index of 2.34. The highest grade of MnO in the concentrate is 52.6% with a selectivity index of 4.10, which is obtained using high-intensity wet magnetic separation. The highest separation efficiency (almost 54.2%) is also achieved by this method. For developing a suitable flowsheet, the combination of various methods including gravity-flotation (cationic and anionic), gravity-magnetic, and gravity-gravity was examined. Among the combined methods, the combination of tabling and cationic flotation methods has resulted in a concentrate containing 39.9% MnO with an acceptable recovery of 71.5%, which seems a more suitable flowsheet for development on the industrial scale. In this research, to achieve an appropriate flowsheet for the processing of low-grade manganese ore, some kinds of beneficiation methods have been investigated and compared. The used ore sample contains an average grade of 13.8% MnO. The valuable mineral containing manganese is pyrolusite, and calcite is the main gangue mineral in the ore. Gravity (jigging and tabling), high-intensity magnetic, and flotation (cationic and anionic) methods were examined in this study. Among the applied methods, cationic flotation has the highest manganese recovery in the concentrate (77.4%) with a selectivity index of 2.34. The highest grade of MnO in the concentrate is 52.6% with a selectivity index of 4.10, which is obtained using high-intensity wet magnetic separation. The highest separation efficiency (almost 54.2%) is also achieved by this method. For developing a suitable flowsheet, the combination of various methods including gravity-flotation (cationic and anionic), gravity-magnetic, and gravity-gravity was examined. Among the combined methods, the combination of tabling and cationic flotation methods has resulted in a concentrate containing 39.9% MnO with an acceptable recovery of 71.5%, which seems a more suitable flowsheet for development on the industrial scale.

https://ceej.aut.ac.ir/article_5435_18cef2ff7b8efa2d2a44bbfb5b244ce8.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 56 5 2024 07 22 Numerical modeling and analysis of the effect of surface groundwater flow and natural convection on the heat exchange of energy pile Numerical modeling and analysis of the effect of surface groundwater flow and natural convection on the heat exchange of energy pile 629 650 5441 10.22060/ceej.2024.23014.8089 FA Makan Fattahian MSc, Geotechnical Group, Civil Engineering Faculty, Tarbiat Modares University, Tehran, Iran Mohammad Hosain Sobhdam Professor, Geotechnical Group, Civil Engineering Faculty, Sharif University of Technology, Tehran, Iran Mohammad Mehdi Ahmadi Professor, Geotechnical Group, Civil Engineering Faculty, Sharif University of Technology, Tehran, Iran Journal Article 2024 02 22 The use of renewable energy, particularly shallow geothermal energy, for heating and cooling various spaces during both hot and cold seasons has received considerable attention. Therefore, investigating the natural factors affecting the efficiency of this system, especially the groundwater flow, is of particular importance. The presence of groundwater flow significantly increases the efficiency of shallow geothermal systems. It has been found that the existence of groundwater flow significantly improves the efficiency of the shallow geothermal energy system. However, the assessment of system efficiency under the influence of groundwater flow is often subjected to error and has been inadequately addressed in the literature. In this study, an energy pile was modeled for a period of 90 days using COMSOL Multiphysics software and the finite element method, taking into account surface groundwater flow. The modeling assumes constant soil and inlet fluid temperature. The analysis was carried out for heating and cooling scenarios with various U-shaped pipe existence of groundwater flow. The results indicate that the presence of surface groundwater flow due to natural convection, independent of soil temperature, leads to a significant reduction in system performance. The use of renewable energy, particularly shallow geothermal energy, for heating and cooling various spaces during both hot and cold seasons has received considerable attention. Therefore, investigating the natural factors affecting the efficiency of this system, especially the groundwater flow, is of particular importance. The presence of groundwater flow significantly increases the efficiency of shallow geothermal systems. It has been found that the existence of groundwater flow significantly improves the efficiency of the shallow geothermal energy system. However, the assessment of system efficiency under the influence of groundwater flow is often subjected to error and has been inadequately addressed in the literature. In this study, an energy pile was modeled for a period of 90 days using COMSOL Multiphysics software and the finite element method, taking into account surface groundwater flow. The modeling assumes constant soil and inlet fluid temperature. The analysis was carried out for heating and cooling scenarios with various U-shaped pipe existence of groundwater flow. The results indicate that the presence of surface groundwater flow due to natural convection, independent of soil temperature, leads to a significant reduction in system performance.

https://ceej.aut.ac.ir/article_5441_b40077b6e7c0a8516d57085f5073610e.pdf