Pub Date : 2021-06-26DOI: 10.22075/JRCE.2021.21809.1454
S. Girish, T. Soumya, Sahana Girish
The aspects of the durability of concrete that need significant attention in the current world demand the intense focus towards inventions in self-repairable materials. Bioengineered concrete using Bacillus sphaericus is one such novel trial. One needs to arrive at such an optimum combination of materials that involve the contribution of bacteria to resolve the issues of repair and rehabilitation effectively. The inherent properties of Bacillus sphaericus paved the way to arrive at the compatible combination of bacteria with nutrients in concrete to achieve self-repairable bioengineered concrete. Since the repairing agent used here performs at a micro level to precipitate stable calcite there is an indeed study carried out through SEM, XRD, EDAX, and Digital microscopic images to come out with an ideal solution for concrete repair work at the micro-level along with standard tests such as compressive strength. The results of these different tests on the bioengineered concrete using four Bacillus species of bacteria show that the best performance both in strength and durability is attained by bacteria Bacillus sphaericus with calcium lactate as a nutrient medium.
{"title":"MICROSTRUCTURE ANALYSIS OF BIO ENGINEERED CONCRETE UNDER THE CONCEPT OF SELF HEALING","authors":"S. Girish, T. Soumya, Sahana Girish","doi":"10.22075/JRCE.2021.21809.1454","DOIUrl":"https://doi.org/10.22075/JRCE.2021.21809.1454","url":null,"abstract":"The aspects of the durability of concrete that need significant attention in the current world demand the intense focus towards inventions in self-repairable materials. Bioengineered concrete using Bacillus sphaericus is one such novel trial. One needs to arrive at such an optimum combination of materials that involve the contribution of bacteria to resolve the issues of repair and rehabilitation effectively. The inherent properties of Bacillus sphaericus paved the way to arrive at the compatible combination of bacteria with nutrients in concrete to achieve self-repairable bioengineered concrete. Since the repairing agent used here performs at a micro level to precipitate stable calcite there is an indeed study carried out through SEM, XRD, EDAX, and Digital microscopic images to come out with an ideal solution for concrete repair work at the micro-level along with standard tests such as compressive strength. The results of these different tests on the bioengineered concrete using four Bacillus species of bacteria show that the best performance both in strength and durability is attained by bacteria Bacillus sphaericus with calcium lactate as a nutrient medium.","PeriodicalId":52415,"journal":{"name":"Journal of Rehabilitation in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87681247","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 : 2021-05-04DOI: 10.22075/JRCE.2021.22466.1482
M. Adlparvar, M. A. Afshar, Sepehr Aghaeipour
ABSTRACTSeismic base isolators and dampers are commonly used as control tools in building frames to mitigate earthquake damage. This study proposes and investigates a structural system consisting of a central fixed core and an isolated section, the two parts of which are connected to each other by a damper. In new structures, called partially isolated (PI) structures, the interaction between conventional frames with fixed bases and frames equipped with control tools including isolators and dampers is measured using a three-mass model by three simplified differential equations of motion. Validating the proposed model provided good results. The model with various modes of partial isolation and certain mass ratios was subjected to seven near-fault and seven far-fault earthquakes to be evaluated. The mean displacement, acceleration, and shear responses of the structural-isolating-damping model were compared with those of fully isolated (FI) and fully fixed (FF) structures. The results showed that by connecting the two parts, responses of the fixed part to FF structure and those of the isolated part to FI structure significantly improved. Under near-fault earthquakes, the displacement response reduction of the fixed part to FF model was estimated to be about 20% and the response of the isolated part to FI model was about 50%. Due to the functional weaknesses observed in FI structures including large displacement of the structure base, poor performance of the isolator in near-fault earthquakes, and high costs of preparing and installing the isolation system, these points were significantly resolved in PI structures.
{"title":"Three-mass Structural-isolating-damping Model Subjected to Near- and Far-fault Earthquakes","authors":"M. Adlparvar, M. A. Afshar, Sepehr Aghaeipour","doi":"10.22075/JRCE.2021.22466.1482","DOIUrl":"https://doi.org/10.22075/JRCE.2021.22466.1482","url":null,"abstract":"ABSTRACTSeismic base isolators and dampers are commonly used as control tools in building frames to mitigate earthquake damage. This study proposes and investigates a structural system consisting of a central fixed core and an isolated section, the two parts of which are connected to each other by a damper. In new structures, called partially isolated (PI) structures, the interaction between conventional frames with fixed bases and frames equipped with control tools including isolators and dampers is measured using a three-mass model by three simplified differential equations of motion. Validating the proposed model provided good results. The model with various modes of partial isolation and certain mass ratios was subjected to seven near-fault and seven far-fault earthquakes to be evaluated. The mean displacement, acceleration, and shear responses of the structural-isolating-damping model were compared with those of fully isolated (FI) and fully fixed (FF) structures. The results showed that by connecting the two parts, responses of the fixed part to FF structure and those of the isolated part to FI structure significantly improved. Under near-fault earthquakes, the displacement response reduction of the fixed part to FF model was estimated to be about 20% and the response of the isolated part to FI model was about 50%. Due to the functional weaknesses observed in FI structures including large displacement of the structure base, poor performance of the isolator in near-fault earthquakes, and high costs of preparing and installing the isolation system, these points were significantly resolved in PI structures.","PeriodicalId":52415,"journal":{"name":"Journal of Rehabilitation in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87388611","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 : 2021-05-04DOI: 10.22075/JRCE.2021.21760.1452
Seyyed Hamed Farhang, O. Rezaifar, M. Sharbatdar, Alireza Ahmady Fard
The application of Digital Image Processing (DIP) and computer vision is increasing in civil engineering branches nowadays. By implementing DIP methods, analyzation, and detection of intended objects and elements on the images will be done. So, these methods can be used for automatic inspection and decreasing manpower's direct controls on structures and infrastructures. This paper will study the application of DIP such as health monitoring and damage detection in structures. After reviewing various researches in this field, a classification including five classes was done. These classes including 1-identification and evaluation of the crack, 2-identification and evaluation of defects in steel structures, 3-identification and evaluation of other imperfections and defects, 4-deflection, deformation, and vibration assessment, and 5-identification of texture, dimensions, elements, and components. The researches also are classified based on various aspects such as the implemented methods, specification of images, the performance of the method, and so on. Finally, after investigating the shortage of researches, the future suggestion for researchers was made.
{"title":"Evaluation of Different Methods of Machine Vision in Health Monitoring and Damage Detection of Structures","authors":"Seyyed Hamed Farhang, O. Rezaifar, M. Sharbatdar, Alireza Ahmady Fard","doi":"10.22075/JRCE.2021.21760.1452","DOIUrl":"https://doi.org/10.22075/JRCE.2021.21760.1452","url":null,"abstract":"The application of Digital Image Processing (DIP) and computer vision is increasing in civil engineering branches nowadays. By implementing DIP methods, analyzation, and detection of intended objects and elements on the images will be done. So, these methods can be used for automatic inspection and decreasing manpower's direct controls on structures and infrastructures. This paper will study the application of DIP such as health monitoring and damage detection in structures. After reviewing various researches in this field, a classification including five classes was done. These classes including 1-identification and evaluation of the crack, 2-identification and evaluation of defects in steel structures, 3-identification and evaluation of other imperfections and defects, 4-deflection, deformation, and vibration assessment, and 5-identification of texture, dimensions, elements, and components. The researches also are classified based on various aspects such as the implemented methods, specification of images, the performance of the method, and so on. Finally, after investigating the shortage of researches, the future suggestion for researchers was made.","PeriodicalId":52415,"journal":{"name":"Journal of Rehabilitation in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77620761","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 : 2021-05-02DOI: 10.22075/JRCE.2021.22347.1474
M. Bilema, M. Aman, N. Hassan, Z. Al-Saffar, K. Rogo, N. Abdullah
The compacting and mixing processes involving hot mix asphalt during asphalt production can lead to air pollution as a result of a high volatile organic compound. An alternative solution that can reduce greenhouse gas emissions is by using warm-mix asphalt (WMA). A proper application of additives to the WMA can improve the asphalt mixture's strength, durability, and workability. In this study, a 60/70 grade asphalt binder was added with 5% of crumb rubber (CR) and three different WMA additives at the recommended dosages, namely Sasobit, Cecabase, and Rediset. The wet method was used to blend the additives with virgin asphalt binders. The mixing and compacting temperatures were set at 135°C and 125°C, respectively, to mix the asphalt mixture. Mechanical performance tests were performed to evaluate the impact of WAM additives with CR on asphalt mixture. Based on the results, all the modified asphalt mixtures showed a better mechanical performance than the virgin asphalt mixture in terms of indirect tensile strength, moisture resistance, permanent deformation, and stiffness. Among all the WMA additives, Sasobit with CR showed the most significant impact on the asphalt mixture's performance.
{"title":"Influence of crumb rubber incorporating different warm mix asphalt additives on the mechanical performance of the WMA mixture","authors":"M. Bilema, M. Aman, N. Hassan, Z. Al-Saffar, K. Rogo, N. Abdullah","doi":"10.22075/JRCE.2021.22347.1474","DOIUrl":"https://doi.org/10.22075/JRCE.2021.22347.1474","url":null,"abstract":"The compacting and mixing processes involving hot mix asphalt during asphalt production can lead to air pollution as a result of a high volatile organic compound. An alternative solution that can reduce greenhouse gas emissions is by using warm-mix asphalt (WMA). A proper application of additives to the WMA can improve the asphalt mixture's strength, durability, and workability. In this study, a 60/70 grade asphalt binder was added with 5% of crumb rubber (CR) and three different WMA additives at the recommended dosages, namely Sasobit, Cecabase, and Rediset. The wet method was used to blend the additives with virgin asphalt binders. The mixing and compacting temperatures were set at 135°C and 125°C, respectively, to mix the asphalt mixture. Mechanical performance tests were performed to evaluate the impact of WAM additives with CR on asphalt mixture. Based on the results, all the modified asphalt mixtures showed a better mechanical performance than the virgin asphalt mixture in terms of indirect tensile strength, moisture resistance, permanent deformation, and stiffness. Among all the WMA additives, Sasobit with CR showed the most significant impact on the asphalt mixture's performance.","PeriodicalId":52415,"journal":{"name":"Journal of Rehabilitation in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74316124","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 : 2021-05-01DOI: 10.22075/JRCE.2021.19219.1363
H. Bakhshi, Z. Rezaie
Seismicity zoning was conducted for different areas of Iran due to general zoning in relative regulations. For increasing reliability in achieving desired safety margin and select a carefully basic acceleration of plan due to the sensitivity of the subject and usage of this parameter in the calculation of the basic shear and control on stability of the construction components, on the other hand, It is essential to zoning more accurate and partially. In this paper, in order to preparation of same acceleration maps of both the horizontal and the vertical component of the acceleration as a case study in the city of Sabzevar in Iran, the seismic springs identified and seismic parameters of the area extracted. According to attenuation relationships and the proper reasonable tree, probabilistic seismic hazard analysis was conducted. The effect of the vertical component was also applied. Two soil type has been selected for review. The first type of soil based on soil type I, II and second type of soil based on soil type III, IV of soil classification based on Iran’s standard No. 2800. After doing the analysis of same acceleration maps according to different design levels with a return period of 475, 225, 72 and 2475 and based on seismic improvement buildings instruction in 50 years of useful life and two types of soil were calculated and plotted. Also, the results of the analysis of the potential risk of seismic with the results for the study zoning area Iran’s standard No. 2800 were compared.
{"title":"Preparation of same acceleration maps for use in the improvement of structures in Sabzevar city","authors":"H. Bakhshi, Z. Rezaie","doi":"10.22075/JRCE.2021.19219.1363","DOIUrl":"https://doi.org/10.22075/JRCE.2021.19219.1363","url":null,"abstract":"Seismicity zoning was conducted for different areas of Iran due to general zoning in relative regulations. For increasing reliability in achieving desired safety margin and select a carefully basic acceleration of plan due to the sensitivity of the subject and usage of this parameter in the calculation of the basic shear and control on stability of the construction components, on the other hand, It is essential to zoning more accurate and partially. In this paper, in order to preparation of same acceleration maps of both the horizontal and the vertical component of the acceleration as a case study in the city of Sabzevar in Iran, the seismic springs identified and seismic parameters of the area extracted. According to attenuation relationships and the proper reasonable tree, probabilistic seismic hazard analysis was conducted. The effect of the vertical component was also applied. Two soil type has been selected for review. The first type of soil based on soil type I, II and second type of soil based on soil type III, IV of soil classification based on Iran’s standard No. 2800. After doing the analysis of same acceleration maps according to different design levels with a return period of 475, 225, 72 and 2475 and based on seismic improvement buildings instruction in 50 years of useful life and two types of soil were calculated and plotted. Also, the results of the analysis of the potential risk of seismic with the results for the study zoning area Iran’s standard No. 2800 were compared.","PeriodicalId":52415,"journal":{"name":"Journal of Rehabilitation in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85080453","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 : 2021-05-01DOI: 10.22075/JRCE.2021.21425.1446
A. Ardakani, A. Namaei
This study evaluates geocell reinforced slope behavior under seismic loading using calibrated hypoplastic soil constitutive model. The constitutive soil model used in this simulation was calibrated for poorly graded dense sand by conducting a series of triaxial and odometer tests. A three dimensional analysis is carried out to simulate geocells and this soil model using the finite element software PLAXIS3D. To investigate the geocell seismic behavior, the lateral displacement, induced tensile force in geocell, slope stability and frequency content effect have been assessed. Furthermore, a comparison has been made among hypoplastic, Hardening soil with small strain and Mohr-Coulomb model. The obtained results indicated that the volumetric plastic strain and intergranular strain consideration by hypoplastic model had a significant effect on the lateral displacement of the reinforced and unreinforced slope. Using the geocell layers leaded to decrease the plastic points. This behavior caused to decrease the estimated results difference when performing three constitutive models as soil failure criterion. Also, the tensile force showed hypoplastic model was not sensitive to the earthquake reversible force. In addition, it was found that the geocells lost their effect when the PGA increased and the slope was apt to fail.
{"title":"Geocell reinforced slope behavior under seismic loading using calibrated hypoplastic soil constitutive model","authors":"A. Ardakani, A. Namaei","doi":"10.22075/JRCE.2021.21425.1446","DOIUrl":"https://doi.org/10.22075/JRCE.2021.21425.1446","url":null,"abstract":"This study evaluates geocell reinforced slope behavior under seismic loading using calibrated hypoplastic soil constitutive model. The constitutive soil model used in this simulation was calibrated for poorly graded dense sand by conducting a series of triaxial and odometer tests. A three dimensional analysis is carried out to simulate geocells and this soil model using the finite element software PLAXIS3D. To investigate the geocell seismic behavior, the lateral displacement, induced tensile force in geocell, slope stability and frequency content effect have been assessed. Furthermore, a comparison has been made among hypoplastic, Hardening soil with small strain and Mohr-Coulomb model. The obtained results indicated that the volumetric plastic strain and intergranular strain consideration by hypoplastic model had a significant effect on the lateral displacement of the reinforced and unreinforced slope. Using the geocell layers leaded to decrease the plastic points. This behavior caused to decrease the estimated results difference when performing three constitutive models as soil failure criterion. Also, the tensile force showed hypoplastic model was not sensitive to the earthquake reversible force. In addition, it was found that the geocells lost their effect when the PGA increased and the slope was apt to fail.","PeriodicalId":52415,"journal":{"name":"Journal of Rehabilitation in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75544669","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 : 2021-05-01DOI: 10.22075/JRCE.2020.21334.1444
M. Adlparvar, M. Parsa
In spite of many benefits, FRP materials are susceptible to elevated temperatures. On the other hand, because FRP laminates are different from other FRP materials, data acquired from investigations concerning FRP materials cannot be suggested for FRP laminates. An assessment of the tensile performance of fibers impregnated by epoxy resin as binder is needed. In recent decades, many methods have been presented to protect fiber reinforced polymer (FRP) composites against high temperatures. The application of fire protection mortar is a low-cost and easy technique among all methods. In this investigation, the influence of fire protection mortar on the improvement of the tensile strength of glass fiber reinforced polymer (GFRP) and carbon fiber reinforced polymer (CFRP) laminates was evaluated. For this object, over 200 FRP laminates with or without fire protection mortar were tested at various elevated temperatures. Investigated temperatures varied from 25°C to 500°C. According to the results obtained from this study, the strength of FRP laminates considerably reduced following the laminates experienced the temperatures higher than 400°C. However, the samples covered with fire protection mortar underwent lower the tensile strength decrements. Eventually, a linear model was presented to estimate the strength of FRP laminates including or excluding protective mortar at elevated temperatures on the basis of linear regressions carried out on test data.
{"title":"The Improvement of the Tensile Behavior of CFRP and GFRP Laminates at Elevated Temperatures Using Fire Protection Mortar","authors":"M. Adlparvar, M. Parsa","doi":"10.22075/JRCE.2020.21334.1444","DOIUrl":"https://doi.org/10.22075/JRCE.2020.21334.1444","url":null,"abstract":"In spite of many benefits, FRP materials are susceptible to elevated temperatures. On the other hand, because FRP laminates are different from other FRP materials, data acquired from investigations concerning FRP materials cannot be suggested for FRP laminates. An assessment of the tensile performance of fibers impregnated by epoxy resin as binder is needed. In recent decades, many methods have been presented to protect fiber reinforced polymer (FRP) composites against high temperatures. The application of fire protection mortar is a low-cost and easy technique among all methods. In this investigation, the influence of fire protection mortar on the improvement of the tensile strength of glass fiber reinforced polymer (GFRP) and carbon fiber reinforced polymer (CFRP) laminates was evaluated. For this object, over 200 FRP laminates with or without fire protection mortar were tested at various elevated temperatures. Investigated temperatures varied from 25°C to 500°C. According to the results obtained from this study, the strength of FRP laminates considerably reduced following the laminates experienced the temperatures higher than 400°C. However, the samples covered with fire protection mortar underwent lower the tensile strength decrements. Eventually, a linear model was presented to estimate the strength of FRP laminates including or excluding protective mortar at elevated temperatures on the basis of linear regressions carried out on test data.","PeriodicalId":52415,"journal":{"name":"Journal of Rehabilitation in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91139787","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 : 2021-05-01DOI: 10.22075/JRCE.2021.20745.1430
Farimah Ghods, M. Khodakarami, R. Vahdani
In this paper, by using direct modeling of the soil-pipe line system using finite element modelling (FEM) in OpenSEES software and integration with the particle swarm optimization (PSO) algorithm which is provided in MATLAB software in the reciprocating method, which is repeated in enough epochs, the optimal intervals of the anchor blocks has been gained and the effect of different parameters of pipe diameter, pipe length, burial depth, different soils and different earthquake stimuli on the seismic behavior of pipes having anchor blocks investigated. The results show that the change in the depth of the burial and the diameter of the pipe has no effect on the anchor block optimal intervals. Also, increasing the length of the pipe will cause to increase the proposed optimal distance between the anchor blocks. The levels of earthquake hazard and soil type, as well as the length of the pipe, are factors affecting on the distance between the anchor blocks. The simultaneous effect of softening the soil and increasing the level of the earthquake hazard increases the distance between the anchor blocks.
{"title":"Determination of optimal Distance of Anchor-blocks in Buried Oil Pipelines Considering the Effects of the Dynamic Soil-Pipe Interaction","authors":"Farimah Ghods, M. Khodakarami, R. Vahdani","doi":"10.22075/JRCE.2021.20745.1430","DOIUrl":"https://doi.org/10.22075/JRCE.2021.20745.1430","url":null,"abstract":"In this paper, by using direct modeling of the soil-pipe line system using finite element modelling (FEM) in OpenSEES software and integration with the particle swarm optimization (PSO) algorithm which is provided in MATLAB software in the reciprocating method, which is repeated in enough epochs, the optimal intervals of the anchor blocks has been gained and the effect of different parameters of pipe diameter, pipe length, burial depth, different soils and different earthquake stimuli on the seismic behavior of pipes having anchor blocks investigated. The results show that the change in the depth of the burial and the diameter of the pipe has no effect on the anchor block optimal intervals. Also, increasing the length of the pipe will cause to increase the proposed optimal distance between the anchor blocks. The levels of earthquake hazard and soil type, as well as the length of the pipe, are factors affecting on the distance between the anchor blocks. The simultaneous effect of softening the soil and increasing the level of the earthquake hazard increases the distance between the anchor blocks.","PeriodicalId":52415,"journal":{"name":"Journal of Rehabilitation in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82187460","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 : 2021-05-01DOI: 10.22075/JRCE.2021.20066.1396
Mohammad Babaeia, Y. Mohammadi, A. Ghannadiasl
The purpose of this study is to obtain one of the important dynamical properties, namely natural frequency (ω) for a number of tall buildings with tube and tapered tube systems. Furthermore, it presents an approximate method to analyze the free vibration of tall buildings by tube, tube-in-tube, bundled tube, and tapered tube structures. The method we have proposed would enable us to compute the natural frequency of tubular vertical and tapered tall buildings by the help of computer programming. The models were analyzed by finite element and analytical methods. The results indicate that the investigated analytical method correctly calculates the natural frequency and is in decent accord with the finite element results and has better compatibility with tapered structures without angle with higher altitude. The resulting computational error is very low. Also, this analytical method has the least error for tube systems and the highest error is for tube-in-tube systems.
{"title":"Dynamic Analysis of Tapered Tall Buildings with Different Tube Structural Systems","authors":"Mohammad Babaeia, Y. Mohammadi, A. Ghannadiasl","doi":"10.22075/JRCE.2021.20066.1396","DOIUrl":"https://doi.org/10.22075/JRCE.2021.20066.1396","url":null,"abstract":"The purpose of this study is to obtain one of the important dynamical properties, namely natural frequency (ω) for a number of tall buildings with tube and tapered tube systems. Furthermore, it presents an approximate method to analyze the free vibration of tall buildings by tube, tube-in-tube, bundled tube, and tapered tube structures. The method we have proposed would enable us to compute the natural frequency of tubular vertical and tapered tall buildings by the help of computer programming. The models were analyzed by finite element and analytical methods. The results indicate that the investigated analytical method correctly calculates the natural frequency and is in decent accord with the finite element results and has better compatibility with tapered structures without angle with higher altitude. The resulting computational error is very low. Also, this analytical method has the least error for tube systems and the highest error is for tube-in-tube systems.","PeriodicalId":52415,"journal":{"name":"Journal of Rehabilitation in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76869895","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 : 2021-05-01DOI: 10.22075/JRCE.2021.20914.1436
Sama Karkhaneh, A. Tarighat, S. Jahromi
Sulfate attack reduces the service life of concrete structures, which isn't possible to repair simply. Implementation of many factors influencing the sulfate resistance, sample scaling, and results in the least possible time is some problems of experimental studies. Therefore, numerical simulations, as well as the new methods along with experimental studies, have been led to better evaluation of sulfate attack within a shorter time and at a lower cost. In the present study, the effective factors, causes, and mechanisms of sulfate attack, examples of this phenomenon in real projects, and the previous studies in this regard, in particular, the development of the thermodynamic study of cement under sulfate attack as a fast and inexpensive solution have been reviewed. The present investigation is divided into three parts, first the sulfate attack mechanism, second the factors influencing phases containing sulfate formation, and third a review of the methods and results of the studies, focusing on the development of thermodynamic models in cement sulfate attack especially. Finally, the results of the studies show that common experimental methods related to concrete sulfate resistance evaluation can't always simulate what is actually happening; subsequently, the results of experimental studies and real cases are sometimes different. So, numerical models, in particular, thermodynamic simulation, either alone or in combination with experimental studies, can be a desirable solution for enhancing the ability to predict engineering behavior of concrete structures in the sulfate environment. Subsequently, it results in making better decisions to tackle and prevent deterioration caused by sulfate attack.
{"title":"Thermodynamic Study of Cement Paste under Sulfate Attack: A Review","authors":"Sama Karkhaneh, A. Tarighat, S. Jahromi","doi":"10.22075/JRCE.2021.20914.1436","DOIUrl":"https://doi.org/10.22075/JRCE.2021.20914.1436","url":null,"abstract":"Sulfate attack reduces the service life of concrete structures, which isn't possible to repair simply. Implementation of many factors influencing the sulfate resistance, sample scaling, and results in the least possible time is some problems of experimental studies. Therefore, numerical simulations, as well as the new methods along with experimental studies, have been led to better evaluation of sulfate attack within a shorter time and at a lower cost. In the present study, the effective factors, causes, and mechanisms of sulfate attack, examples of this phenomenon in real projects, and the previous studies in this regard, in particular, the development of the thermodynamic study of cement under sulfate attack as a fast and inexpensive solution have been reviewed. The present investigation is divided into three parts, first the sulfate attack mechanism, second the factors influencing phases containing sulfate formation, and third a review of the methods and results of the studies, focusing on the development of thermodynamic models in cement sulfate attack especially. Finally, the results of the studies show that common experimental methods related to concrete sulfate resistance evaluation can't always simulate what is actually happening; subsequently, the results of experimental studies and real cases are sometimes different. So, numerical models, in particular, thermodynamic simulation, either alone or in combination with experimental studies, can be a desirable solution for enhancing the ability to predict engineering behavior of concrete structures in the sulfate environment. Subsequently, it results in making better decisions to tackle and prevent deterioration caused by sulfate attack.","PeriodicalId":52415,"journal":{"name":"Journal of Rehabilitation in Civil Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83996037","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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