Pub Date : 2021-01-02DOI: 10.1080/24705314.2020.1823557
K. Yang
ABSTRACT This study aimed to estimate the shear friction response of lightweight concrete made using bottom ash aggregates and air foam (LWC-BF) and determine the design parameters including shear transfer capacity, cohesion, and friction angle of such concrete at different interface conditions. The shear friction parameters were straightforwardly formulated from the extension version of the integrated mechanical models derived in our previous study based on the upper bound theorem of concrete plasticity. Eighteen non-reinforced push-off specimens (nine monolithic interfaces and nine interfaces with smooth construction joints) were tested under direct shear and the additional compressive stresses normally applied to the interfaces. The test parameters considered in different interface conditions were the compressive strength of concrete and the magnitude of compressive stresses. The experimental and analytical results showed that the addition of air foam slightly decreases the angle of friction of monolithic interfaces but insignificantly affects that of smooth construction joints. Thus, the effect of air foam added up to 20% by volume on the cohesion and friction angle of concrete was marginal. Therefore, the proposed shear friction parameters are promising to reasonably assess the shear friction strength of LWC-BF interfaces.
{"title":"Shear friction response of lightweight concrete using bottom ash aggregates and air foams","authors":"K. Yang","doi":"10.1080/24705314.2020.1823557","DOIUrl":"https://doi.org/10.1080/24705314.2020.1823557","url":null,"abstract":"ABSTRACT This study aimed to estimate the shear friction response of lightweight concrete made using bottom ash aggregates and air foam (LWC-BF) and determine the design parameters including shear transfer capacity, cohesion, and friction angle of such concrete at different interface conditions. The shear friction parameters were straightforwardly formulated from the extension version of the integrated mechanical models derived in our previous study based on the upper bound theorem of concrete plasticity. Eighteen non-reinforced push-off specimens (nine monolithic interfaces and nine interfaces with smooth construction joints) were tested under direct shear and the additional compressive stresses normally applied to the interfaces. The test parameters considered in different interface conditions were the compressive strength of concrete and the magnitude of compressive stresses. The experimental and analytical results showed that the addition of air foam slightly decreases the angle of friction of monolithic interfaces but insignificantly affects that of smooth construction joints. Thus, the effect of air foam added up to 20% by volume on the cohesion and friction angle of concrete was marginal. Therefore, the proposed shear friction parameters are promising to reasonably assess the shear friction strength of LWC-BF interfaces.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1823557","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48296654","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 : 2021-01-02DOI: 10.1080/24705314.2020.1823556
J. Vanlalruata, C. Marthong
ABSTRACT The aim of the present study is to determine the loss in the flexural strength capacity of a reinforced concrete (RC) beam due to the presence of cold joint under two conditions: (i) different mix of concrete and (ii) different age of the cold joint. Indian Standard method of testing the flexural strength of an RC beam was adopted. In this study 40 beams were casted out of which 8 were of controlled beams and the remaining 32 were of cold jointed specimens. Cold jointed specimens were casted up to half by inclining approximately at 45° to replicate the common practice on site and the remaining portions were casted at different intervals of time. From the experimental study, the amount of loss in the flexural strength capacity of the RC beams due to the presence of cold joint for different age was observed. A deduction chart to account for the loss due to the presence of cold joint is proposed.
{"title":"Effect of cold joint on the flexural strength of RC beam","authors":"J. Vanlalruata, C. Marthong","doi":"10.1080/24705314.2020.1823556","DOIUrl":"https://doi.org/10.1080/24705314.2020.1823556","url":null,"abstract":"ABSTRACT The aim of the present study is to determine the loss in the flexural strength capacity of a reinforced concrete (RC) beam due to the presence of cold joint under two conditions: (i) different mix of concrete and (ii) different age of the cold joint. Indian Standard method of testing the flexural strength of an RC beam was adopted. In this study 40 beams were casted out of which 8 were of controlled beams and the remaining 32 were of cold jointed specimens. Cold jointed specimens were casted up to half by inclining approximately at 45° to replicate the common practice on site and the remaining portions were casted at different intervals of time. From the experimental study, the amount of loss in the flexural strength capacity of the RC beams due to the presence of cold joint for different age was observed. A deduction chart to account for the loss due to the presence of cold joint is proposed.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1823556","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47712196","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 : 2020-12-31DOI: 10.1080/24705314.2020.1823555
Ishfaq Rashid Sheikh, M. Y. Shah
ABSTRACT Construction and demolition (C&D) wastes are found to be the main source of unwanted materials produced worldwide. Due to the insufficient amount of high-quality fresh limestone aggregates, construction and demolition waste are used as an alternative base course material for highway construction. The stabilization of C&D recycled aggregate waste with ordinary portland cement (OPC) has been repeatedly used by the researchers to improve the performance of the base course in highway construction. The studies related to the geosynthetic-reinforced C&D waste are limited. In this study, the efficacy of geosynthetics reinforced bases was evaluated within the base course with three different base thickness (120, 150 and 200 mm). Two different infill materials, namely, C&D waste and limestone aggregates were used and plate load tests were conducted to simulate traffic loading over geosynthetic reinforced and unreinforced unpaved test sections. This study aims to present the results in terms of load versus deformation and load versus vertical stress distribution. It was observed that the C&D waste improvement factor is more than virgin aggregates (limestone aggregates). Due to the inclusion of geocell and geotextile, the average bearing capacity improvement factor enhances by 62% and the vertical stresses decrease significantly.
{"title":"Performance evaluation of construction and demolition waste aggregates as an alternative base course material in highway construction","authors":"Ishfaq Rashid Sheikh, M. Y. Shah","doi":"10.1080/24705314.2020.1823555","DOIUrl":"https://doi.org/10.1080/24705314.2020.1823555","url":null,"abstract":"ABSTRACT Construction and demolition (C&D) wastes are found to be the main source of unwanted materials produced worldwide. Due to the insufficient amount of high-quality fresh limestone aggregates, construction and demolition waste are used as an alternative base course material for highway construction. The stabilization of C&D recycled aggregate waste with ordinary portland cement (OPC) has been repeatedly used by the researchers to improve the performance of the base course in highway construction. The studies related to the geosynthetic-reinforced C&D waste are limited. In this study, the efficacy of geosynthetics reinforced bases was evaluated within the base course with three different base thickness (120, 150 and 200 mm). Two different infill materials, namely, C&D waste and limestone aggregates were used and plate load tests were conducted to simulate traffic loading over geosynthetic reinforced and unreinforced unpaved test sections. This study aims to present the results in terms of load versus deformation and load versus vertical stress distribution. It was observed that the C&D waste improvement factor is more than virgin aggregates (limestone aggregates). Due to the inclusion of geocell and geotextile, the average bearing capacity improvement factor enhances by 62% and the vertical stresses decrease significantly.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1823555","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41697679","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 : 2020-12-31DOI: 10.1080/24705314.2020.1824668
So-Yeong Choi, Il-Sun Kim, E. Yang
ABSTRACT Calcium leaching degradation could be happened in RC members due to the contact with pure water in underground conditions. And it is used that concrete with improved durability by using mineral admixture in the underground structures. Thus, it is needed to evaluate the resistance of calcium leaching for underground concrete mixed with mineral admixtures. In this study to evaluate the effects of long-term calcium leaching on the RC members mixed with mineral admixture are investigated. From the test results, when the RC member is attacked by calcium leaching, the yield load decreased, and the deflection at this time increased. And, the moment at the time of the inflection point of curvature decreased as well. Also, while a continuous decrease in compressive strength occurred with leaching period, the yield point and deflection value of an RC member with relatively low water binder ratio and low replacement ratio of mineral admixture as binder did not show significant changes. Consequently, when the concrete is applied to the underground structure which is exposed to a calcium leaching environment, it is not desirable to use high water-binder ratio or a large amount of mineral admixture as binder.
{"title":"An experimental study on the flexural behavior of RC member under long-term calcium leaching degradation","authors":"So-Yeong Choi, Il-Sun Kim, E. Yang","doi":"10.1080/24705314.2020.1824668","DOIUrl":"https://doi.org/10.1080/24705314.2020.1824668","url":null,"abstract":"ABSTRACT Calcium leaching degradation could be happened in RC members due to the contact with pure water in underground conditions. And it is used that concrete with improved durability by using mineral admixture in the underground structures. Thus, it is needed to evaluate the resistance of calcium leaching for underground concrete mixed with mineral admixtures. In this study to evaluate the effects of long-term calcium leaching on the RC members mixed with mineral admixture are investigated. From the test results, when the RC member is attacked by calcium leaching, the yield load decreased, and the deflection at this time increased. And, the moment at the time of the inflection point of curvature decreased as well. Also, while a continuous decrease in compressive strength occurred with leaching period, the yield point and deflection value of an RC member with relatively low water binder ratio and low replacement ratio of mineral admixture as binder did not show significant changes. Consequently, when the concrete is applied to the underground structure which is exposed to a calcium leaching environment, it is not desirable to use high water-binder ratio or a large amount of mineral admixture as binder.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1824668","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41756296","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 : 2020-09-17DOI: 10.1080/24705314.2020.1783121
Sarranya Banerjee, Aparna (Dey) Ghosh
ABSTRACT This paper presents an optimal design procedure for a nonlinear TMD with Bingham-type damping that can lead to a more economic and realistic design of the damper. The optimization problem is solved in the Genetic Algorithm (GA) framework. Considering small nonlinearities, the nonlinear TMD design using GA is validated through standard equivalent linearization method. The efficacy of the TMD designs is presented through a numerical simulation study on four different single-degree-of-freedom structure-TMD systems subjected to recorded earthquake ground motions. Results indicate that the optimally designed nonlinear TMD with Bingham-type damping can effectively reduce the size of the TMD damping element at the cost of a very slight degradation in control performance as compared to the linear TMD. The improved performance of the nonlinear TMD with Bingham-type damping over the linear TMD that develops post-design nonlinearities is also shown. Further, a robust design procedure of the nonlinear TMD using GA is presented that can cater to perturbations in the natural frequency of the primary structure. Thus, the optimal design procedure using GA for the nonlinear TMD offers several advantages as compared to the statistical linearization approach.
{"title":"Optimal design of nonlinear TMD with Bingham-type damping for base-excited structures","authors":"Sarranya Banerjee, Aparna (Dey) Ghosh","doi":"10.1080/24705314.2020.1783121","DOIUrl":"https://doi.org/10.1080/24705314.2020.1783121","url":null,"abstract":"ABSTRACT This paper presents an optimal design procedure for a nonlinear TMD with Bingham-type damping that can lead to a more economic and realistic design of the damper. The optimization problem is solved in the Genetic Algorithm (GA) framework. Considering small nonlinearities, the nonlinear TMD design using GA is validated through standard equivalent linearization method. The efficacy of the TMD designs is presented through a numerical simulation study on four different single-degree-of-freedom structure-TMD systems subjected to recorded earthquake ground motions. Results indicate that the optimally designed nonlinear TMD with Bingham-type damping can effectively reduce the size of the TMD damping element at the cost of a very slight degradation in control performance as compared to the linear TMD. The improved performance of the nonlinear TMD with Bingham-type damping over the linear TMD that develops post-design nonlinearities is also shown. Further, a robust design procedure of the nonlinear TMD using GA is presented that can cater to perturbations in the natural frequency of the primary structure. Thus, the optimal design procedure using GA for the nonlinear TMD offers several advantages as compared to the statistical linearization approach.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2020-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1783121","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42608952","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 : 2020-09-17DOI: 10.1080/24705314.2020.1783122
Nand Kumar, V. Naranje, S. Salunkhe
ABSTRACT This paper describes a cloud-based software framework to predict cement strength for 2 days, 7 days and 28 days. Levenbarg-Marquardt back-propagation-artificial neural network (LMBP-ANN) is used to build a prediction model. This ANN model uses 70% of data for training (70%, 212 data records), testing (15%, 46 data records) and for validation (15%, 46 data records). A total of 16 significant input parameters are considered for the cement strength prediction. The user interface and software framework are built using the Python programming language. Multiple Python packages are used for the implementation of the ANN model. The cloud server having Ubuntu operating system has been used to host the web application for prediction of cement strength. The software application is tested using real-time data from various cement industries. The prediction of the cement strength of the proposed ANN-based software application appears to be very similar to those currently generated in experimental data in the cement manufacturing industry. The adequacy of the developed model based on the back-propagation ANN algorithm is confirmed as the Pearson correlation of experimental value and predicted value. The calculated value of R for experimentations on the data is 0.82539 and is 0.6813.
{"title":"Cement strength prediction using cloud-based machine learning techniques","authors":"Nand Kumar, V. Naranje, S. Salunkhe","doi":"10.1080/24705314.2020.1783122","DOIUrl":"https://doi.org/10.1080/24705314.2020.1783122","url":null,"abstract":"ABSTRACT This paper describes a cloud-based software framework to predict cement strength for 2 days, 7 days and 28 days. Levenbarg-Marquardt back-propagation-artificial neural network (LMBP-ANN) is used to build a prediction model. This ANN model uses 70% of data for training (70%, 212 data records), testing (15%, 46 data records) and for validation (15%, 46 data records). A total of 16 significant input parameters are considered for the cement strength prediction. The user interface and software framework are built using the Python programming language. Multiple Python packages are used for the implementation of the ANN model. The cloud server having Ubuntu operating system has been used to host the web application for prediction of cement strength. The software application is tested using real-time data from various cement industries. The prediction of the cement strength of the proposed ANN-based software application appears to be very similar to those currently generated in experimental data in the cement manufacturing industry. The adequacy of the developed model based on the back-propagation ANN algorithm is confirmed as the Pearson correlation of experimental value and predicted value. The calculated value of R for experimentations on the data is 0.82539 and is 0.6813.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2020-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1783122","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46228125","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 : 2020-09-17DOI: 10.1080/24705314.2020.1783123
Joydeep Das, Arjun Sil
ABSTRACT The probabilistic approach for estimating deterioration of existing RC bridges due to multiple hazards becomes an important subject for the bridge management system. In the present study, a multi-hazard approach as well as investigation proposed to assess how service life of the bridges affected due to the amalgamation of the physical deterioration (aging) along with earthquake hazards. In this approach, the Weibull distribution is found suitable and employed for determining deterioration in terms of hazard function ha(t) of the bridges due to aging. Conversely, the northeast (NE) region of India is highly tectonically active and prone to earthquakes of higher magnitude (Mw>8). Considering the high seismicity in the study region, respective active faults and their corresponding maximum PGA values are taken into account to evaluate the earthquake hazard of the region in a site specific manner. By applying this proposed approach, significant site specific in-depth ideas and facts about their service life span could be evaluated considering the condition of existing bridges for satisfactory performance that would be helpful in taking rational decisions for the bridge management system (BMS) in terms of safety, rehabilitation, repair and inspection strategies of the bridges available in the study region for sustainable growth.
{"title":"Assessment of multi-hazards affecting service life of existing reinforced concrete (RC) bridges of Barak valley region, Assam, India","authors":"Joydeep Das, Arjun Sil","doi":"10.1080/24705314.2020.1783123","DOIUrl":"https://doi.org/10.1080/24705314.2020.1783123","url":null,"abstract":"ABSTRACT The probabilistic approach for estimating deterioration of existing RC bridges due to multiple hazards becomes an important subject for the bridge management system. In the present study, a multi-hazard approach as well as investigation proposed to assess how service life of the bridges affected due to the amalgamation of the physical deterioration (aging) along with earthquake hazards. In this approach, the Weibull distribution is found suitable and employed for determining deterioration in terms of hazard function ha(t) of the bridges due to aging. Conversely, the northeast (NE) region of India is highly tectonically active and prone to earthquakes of higher magnitude (Mw>8). Considering the high seismicity in the study region, respective active faults and their corresponding maximum PGA values are taken into account to evaluate the earthquake hazard of the region in a site specific manner. By applying this proposed approach, significant site specific in-depth ideas and facts about their service life span could be evaluated considering the condition of existing bridges for satisfactory performance that would be helpful in taking rational decisions for the bridge management system (BMS) in terms of safety, rehabilitation, repair and inspection strategies of the bridges available in the study region for sustainable growth.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2020-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1783123","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43404848","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 : 2020-09-17DOI: 10.1080/24705314.2020.1783120
Keshav K. Sharma, A. Imam, F. Anifowose, Vikas Srivastava
ABSTRACT This article exhibits an experimental study carried out to investigate the combined effect of Silica Fume (SF) and Metakaolin (MK) on the fresh and hardened properties of concrete. The replacement levels of SF were adopted as 5%, 10%, 15%, 20% while that of MK were 5%, 10%, 15%, 20% and 25%. The results for cube testing revealed that the use of SF and MK produces considerably good strength concrete. Based on the experimental observations, an approach to predict the compressive strength using regression modeling was suggested. The result of which rendered a reasonable agreement with the available test data. Moreover, two Artificial Neural Network (ANN) models have also been proposed to predict the compressive strength of concrete using the data obtained from the experimental exercise. Randomized stratification method was used to divide the data samples into training and testing subsets in line with machine learning best practices. The results of the ANN models were found to be in good agreement with experimental values. When compared with the results of empirical models, the respective ANN models gave a better prediction for the compressive strength. This substantiates the reliability of ANN over the empirical models.
{"title":"Compressive strength modeling of blended concrete based on empirical and artificial neural network techniques","authors":"Keshav K. Sharma, A. Imam, F. Anifowose, Vikas Srivastava","doi":"10.1080/24705314.2020.1783120","DOIUrl":"https://doi.org/10.1080/24705314.2020.1783120","url":null,"abstract":"ABSTRACT This article exhibits an experimental study carried out to investigate the combined effect of Silica Fume (SF) and Metakaolin (MK) on the fresh and hardened properties of concrete. The replacement levels of SF were adopted as 5%, 10%, 15%, 20% while that of MK were 5%, 10%, 15%, 20% and 25%. The results for cube testing revealed that the use of SF and MK produces considerably good strength concrete. Based on the experimental observations, an approach to predict the compressive strength using regression modeling was suggested. The result of which rendered a reasonable agreement with the available test data. Moreover, two Artificial Neural Network (ANN) models have also been proposed to predict the compressive strength of concrete using the data obtained from the experimental exercise. Randomized stratification method was used to divide the data samples into training and testing subsets in line with machine learning best practices. The results of the ANN models were found to be in good agreement with experimental values. When compared with the results of empirical models, the respective ANN models gave a better prediction for the compressive strength. This substantiates the reliability of ANN over the empirical models.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2020-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1783120","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43572440","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 : 2020-09-17DOI: 10.1080/24705314.2020.1783124
Hyeongi Lee, A. Hanif, M. Usman, Younghwan Kim, H. Oh, Seong-Kyum Kim
ABSTRACT In this study, porosity assessment of cement mortars containing Precious Slag (PS) Ball – an industrial waste produced by rapid cooling of slag generated from steel making process by Slag Atomizing Technology – is done by Back-Scattered Electron (BSE) image analysis. PS incorporated mortars were fabricated and subsequently evaluated for compressive strength. BSE images were analyzed by pore segmentation method. Binarization on the images using Otsu’s thresholding method was done followed by the porosity determination. As the interfacial attributes were the primary concern, the porosity was determined from the aggregate surface to the 100 μm width. A total of 24 sections were analyzed and the mean values were plotted. Although the PS Ball incorporated mortar exhibited 10% lower strength at 28-day age, it showed stronger and less porous aggregate- matrix interface between (from particle surface up to 35 μm width) as compared to that of normal mortar containing sand, which is justifiable by the chemical composition of PS Ball attributed to the potential chemical binding. Further, the porosity decreased as the distance from aggregate surface increased. While the use of PS Ball is environmentally friendly, its enhanced interfacial properties with some strength loss of resulting cement mortars encourages its use in sustainable construction materials.
{"title":"Interfacial characteristics of cement mortars containing aggregate derived from industrial slag waste","authors":"Hyeongi Lee, A. Hanif, M. Usman, Younghwan Kim, H. Oh, Seong-Kyum Kim","doi":"10.1080/24705314.2020.1783124","DOIUrl":"https://doi.org/10.1080/24705314.2020.1783124","url":null,"abstract":"ABSTRACT In this study, porosity assessment of cement mortars containing Precious Slag (PS) Ball – an industrial waste produced by rapid cooling of slag generated from steel making process by Slag Atomizing Technology – is done by Back-Scattered Electron (BSE) image analysis. PS incorporated mortars were fabricated and subsequently evaluated for compressive strength. BSE images were analyzed by pore segmentation method. Binarization on the images using Otsu’s thresholding method was done followed by the porosity determination. As the interfacial attributes were the primary concern, the porosity was determined from the aggregate surface to the 100 μm width. A total of 24 sections were analyzed and the mean values were plotted. Although the PS Ball incorporated mortar exhibited 10% lower strength at 28-day age, it showed stronger and less porous aggregate- matrix interface between (from particle surface up to 35 μm width) as compared to that of normal mortar containing sand, which is justifiable by the chemical composition of PS Ball attributed to the potential chemical binding. Further, the porosity decreased as the distance from aggregate surface increased. While the use of PS Ball is environmentally friendly, its enhanced interfacial properties with some strength loss of resulting cement mortars encourages its use in sustainable construction materials.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2020-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1783124","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47010067","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 : 2020-07-02DOI: 10.1080/24705314.2020.1765268
Thanh-Hung Nguyen, A. Le, D. Nguyen
ABSTRACT The concrete reinforced beams, especially in coastal zones, usually show the signs of degradation due to the steel reinforcement corrosion after a period of serving. It causes the strength of the concrete reinforced structures decreasing. Remaining strength of corroded reinforced structures is needed to assess in a specific time. However, it is not easy to have all input data for assessing the service life of reinforced concrete structures because many parameters have been also changed along with the corrosion of steel reinforcements. An algorithm is developed for forecasting the strength remains of the beams in which the reinforcement corrosion is considered. The reinforcement corrosion is assumed as effecting on the diameter of steel bars and the bond between steel bar and concrete. In case of incomplete data, statistical analysis of the corrosion percentage was conducted using Monte Carlo simulations. The results of the algorithm are verified with the published results.
{"title":"Bending strength diagnosis for corroded reinforced concrete beams with attendance of deterministic, random and fuzzy parameters","authors":"Thanh-Hung Nguyen, A. Le, D. Nguyen","doi":"10.1080/24705314.2020.1765268","DOIUrl":"https://doi.org/10.1080/24705314.2020.1765268","url":null,"abstract":"ABSTRACT The concrete reinforced beams, especially in coastal zones, usually show the signs of degradation due to the steel reinforcement corrosion after a period of serving. It causes the strength of the concrete reinforced structures decreasing. Remaining strength of corroded reinforced structures is needed to assess in a specific time. However, it is not easy to have all input data for assessing the service life of reinforced concrete structures because many parameters have been also changed along with the corrosion of steel reinforcements. An algorithm is developed for forecasting the strength remains of the beams in which the reinforcement corrosion is considered. The reinforcement corrosion is assumed as effecting on the diameter of steel bars and the bond between steel bar and concrete. In case of incomplete data, statistical analysis of the corrosion percentage was conducted using Monte Carlo simulations. The results of the algorithm are verified with the published results.","PeriodicalId":43844,"journal":{"name":"Journal of Structural Integrity and Maintenance","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2020-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/24705314.2020.1765268","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48441161","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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