The Experts below are selected from a list of 144 Experts worldwide ranked by ideXlab platform

Yong Liu - One of the best experts on this subject based on the ideXlab platform.

  • Propagation of corrosion and corrosion patterns of bars embedded in RC beams stored in chloride environment for various periods
    Construction and Building Materials, 2017
    Co-Authors: Wenjun Zhu, Raoul François, Yong Liu
    Abstract:

    In this paper, the propagation of chloride-induced corrosion of bars embedded in reinforced concrete (RC) beams exposed to a chloride environment was examined. These bars were exposed to chloride environment for various periods. Then, the cracking of the RC beams was observed and the corroded reinforcements were extracted from the beams in order to investigate the corrosion distribution and propagation. The cross-sectional loss and spatial distribution in the longitudinal direction were studied by cutting the residual reinforcement into several small specimens. By analysing the cross-sectional loss results, it was found that the corrosion developed in a stochastic way. However, the corrosion zone developed gradually from the mid-span of the beam to the two ends, and there was a linear relationship between the extent of the corrosion zone and the corrosion period. Similarly, the degree of Pitting corrosion and general corrosion also increased. The relationship between Pitting corrosion and general corrosion developed along an improved exponential curve, while the Pitting Factor and the general corrosion showed a logarithmic relationship. The results of this investigation could be treated as an envelope curve, which can be helpful to assess the corrosion state of reinforcements situated in aggressive environment and predict the residual life-cycle of corroded constructions. (C) 2017 Elsevier Ltd. All rights reserved.

  • Propagation of corrosion and corrosion patterns of bars embedded in RC beams stored in chloride environment for various periods
    Construction and Building Materials, 2017
    Co-Authors: Wenjun Zhu, Raoul François, Yong Liu
    Abstract:

    Abstract In this paper, the propagation of chloride-induced corrosion of bars embedded in reinforced concrete (RC) beams exposed to a chloride environment was examined. These bars were exposed to chloride environment for various periods. Then, the cracking of the RC beams was observed and the corroded reinforcements were extracted from the beams in order to investigate the corrosion distribution and propagation. The cross-sectional loss and spatial distribution in the longitudinal direction were studied by cutting the residual reinforcement into several small specimens. By analysing the cross-sectional loss results, it was found that the corrosion developed in a stochastic way. However, the corrosion zone developed gradually from the mid-span of the beam to the two ends, and there was a linear relationship between the extent of the corrosion zone and the corrosion period. Similarly, the degree of Pitting corrosion and general corrosion also increased. The relationship between Pitting corrosion and general corrosion developed along an improved exponential curve, while the Pitting Factor and the general corrosion showed a logarithmic relationship. The results of this investigation could be treated as an envelope curve, which can be helpful to assess the corrosion state of reinforcements situated in aggressive environment and predict the residual life-cycle of corroded constructions.

Raoul François - One of the best experts on this subject based on the ideXlab platform.

  • Propagation of corrosion and corrosion patterns of bars embedded in RC beams stored in chloride environment for various periods
    Construction and Building Materials, 2017
    Co-Authors: Wenjun Zhu, Raoul François, Yong Liu
    Abstract:

    In this paper, the propagation of chloride-induced corrosion of bars embedded in reinforced concrete (RC) beams exposed to a chloride environment was examined. These bars were exposed to chloride environment for various periods. Then, the cracking of the RC beams was observed and the corroded reinforcements were extracted from the beams in order to investigate the corrosion distribution and propagation. The cross-sectional loss and spatial distribution in the longitudinal direction were studied by cutting the residual reinforcement into several small specimens. By analysing the cross-sectional loss results, it was found that the corrosion developed in a stochastic way. However, the corrosion zone developed gradually from the mid-span of the beam to the two ends, and there was a linear relationship between the extent of the corrosion zone and the corrosion period. Similarly, the degree of Pitting corrosion and general corrosion also increased. The relationship between Pitting corrosion and general corrosion developed along an improved exponential curve, while the Pitting Factor and the general corrosion showed a logarithmic relationship. The results of this investigation could be treated as an envelope curve, which can be helpful to assess the corrosion state of reinforcements situated in aggressive environment and predict the residual life-cycle of corroded constructions. (C) 2017 Elsevier Ltd. All rights reserved.

  • Propagation of corrosion and corrosion patterns of bars embedded in RC beams stored in chloride environment for various periods
    Construction and Building Materials, 2017
    Co-Authors: Wenjun Zhu, Raoul François, Yong Liu
    Abstract:

    Abstract In this paper, the propagation of chloride-induced corrosion of bars embedded in reinforced concrete (RC) beams exposed to a chloride environment was examined. These bars were exposed to chloride environment for various periods. Then, the cracking of the RC beams was observed and the corroded reinforcements were extracted from the beams in order to investigate the corrosion distribution and propagation. The cross-sectional loss and spatial distribution in the longitudinal direction were studied by cutting the residual reinforcement into several small specimens. By analysing the cross-sectional loss results, it was found that the corrosion developed in a stochastic way. However, the corrosion zone developed gradually from the mid-span of the beam to the two ends, and there was a linear relationship between the extent of the corrosion zone and the corrosion period. Similarly, the degree of Pitting corrosion and general corrosion also increased. The relationship between Pitting corrosion and general corrosion developed along an improved exponential curve, while the Pitting Factor and the general corrosion showed a logarithmic relationship. The results of this investigation could be treated as an envelope curve, which can be helpful to assess the corrosion state of reinforcements situated in aggressive environment and predict the residual life-cycle of corroded constructions.

  • Distribution of corrosion and Pitting Factor of steel in corroded RC beams
    Construction and Building Materials, 2015
    Co-Authors: Raoul François, Vu Hiep Dang, Valerie L'hostis, Richard Gagne
    Abstract:

    The purpose of this work was to study the corrosion distribution along a steel bar in beams of sizes typically used in the construction industry and the ratio between maximum cross-sectional loss and average cross-sectional loss of the steel bar. This work was based on three beams exposed to accelerated natural corrosion for 19-36 months. The cracking maps and crack widths were recorded. After the steel bars had been extracted from the beams and cleaned with Clarke's solution, cross-sectional losses were measured. The experimental results show that average cross-sectional loss of the steel bar correlated well with maximum corrosion crack width. The Pitting Factors of steel bars were mainly between 2.5 and 5.0, and decreased with the increase of average cross-sectional loss. More measurements would be desirable in further research on the Pitting Factor before this Factor is used for predicting the residual mechanical performance of corroded structures. (C) 2015 Elsevier Ltd. All rights reserved.

  • Distribution of corrosion and Pitting Factor of steel in corroded RC beams
    Construction and Building Materials, 2015
    Co-Authors: Raoul François, Vu Hiep Dang, Valérie L’hostis, Richard Gagne
    Abstract:

    Abstract The purpose of this work was to study the corrosion distribution along a steel bar in beams of sizes typically used in the construction industry and the ratio between maximum cross-sectional loss and average cross-sectional loss of the steel bar. This work was based on three beams exposed to accelerated natural corrosion for 19–36 months. The cracking maps and crack widths were recorded. After the steel bars had been extracted from the beams and cleaned with Clarke’s solution, cross-sectional losses were measured. The experimental results show that average cross-sectional loss of the steel bar correlated well with maximum corrosion crack width. The Pitting Factors of steel bars were mainly between 2.5 and 5.0, and decreased with the increase of average cross-sectional loss. More measurements would be desirable in further research on the Pitting Factor before this Factor is used for predicting the residual mechanical performance of corroded structures.

Wenjun Zhu - One of the best experts on this subject based on the ideXlab platform.

  • Propagation of corrosion and corrosion patterns of bars embedded in RC beams stored in chloride environment for various periods
    Construction and Building Materials, 2017
    Co-Authors: Wenjun Zhu, Raoul François, Yong Liu
    Abstract:

    In this paper, the propagation of chloride-induced corrosion of bars embedded in reinforced concrete (RC) beams exposed to a chloride environment was examined. These bars were exposed to chloride environment for various periods. Then, the cracking of the RC beams was observed and the corroded reinforcements were extracted from the beams in order to investigate the corrosion distribution and propagation. The cross-sectional loss and spatial distribution in the longitudinal direction were studied by cutting the residual reinforcement into several small specimens. By analysing the cross-sectional loss results, it was found that the corrosion developed in a stochastic way. However, the corrosion zone developed gradually from the mid-span of the beam to the two ends, and there was a linear relationship between the extent of the corrosion zone and the corrosion period. Similarly, the degree of Pitting corrosion and general corrosion also increased. The relationship between Pitting corrosion and general corrosion developed along an improved exponential curve, while the Pitting Factor and the general corrosion showed a logarithmic relationship. The results of this investigation could be treated as an envelope curve, which can be helpful to assess the corrosion state of reinforcements situated in aggressive environment and predict the residual life-cycle of corroded constructions. (C) 2017 Elsevier Ltd. All rights reserved.

  • Propagation of corrosion and corrosion patterns of bars embedded in RC beams stored in chloride environment for various periods
    Construction and Building Materials, 2017
    Co-Authors: Wenjun Zhu, Raoul François, Yong Liu
    Abstract:

    Abstract In this paper, the propagation of chloride-induced corrosion of bars embedded in reinforced concrete (RC) beams exposed to a chloride environment was examined. These bars were exposed to chloride environment for various periods. Then, the cracking of the RC beams was observed and the corroded reinforcements were extracted from the beams in order to investigate the corrosion distribution and propagation. The cross-sectional loss and spatial distribution in the longitudinal direction were studied by cutting the residual reinforcement into several small specimens. By analysing the cross-sectional loss results, it was found that the corrosion developed in a stochastic way. However, the corrosion zone developed gradually from the mid-span of the beam to the two ends, and there was a linear relationship between the extent of the corrosion zone and the corrosion period. Similarly, the degree of Pitting corrosion and general corrosion also increased. The relationship between Pitting corrosion and general corrosion developed along an improved exponential curve, while the Pitting Factor and the general corrosion showed a logarithmic relationship. The results of this investigation could be treated as an envelope curve, which can be helpful to assess the corrosion state of reinforcements situated in aggressive environment and predict the residual life-cycle of corroded constructions.

Shabbir Safri - One of the best experts on this subject based on the ideXlab platform.

  • Two Contrasting Internal Corrosion Scenarios Assessed by Liquid Petroleum–Internal Corrosion Direct Assessment (LP-ICDA) for the Innovative Development of a Dynamic Pitting Factor
    Volume 2: Pipeline Integrity Management, 2012
    Co-Authors: Patrick J. Teevens, Zhenjin Zhu, Ashish Khera, Abdul Wahab Al-mithin, Shabbir Safri
    Abstract:

    This paper details the complete four-step Liquid Petroleum - Internal Corrosion Direct Assessment (LP-ICDA) for two operationally different liquid petroleum pipeline systems owned by Kuwait Oil Company. The internal corrosion pipeline wall metal losses were originally predicted using a uniform Pitting Factor and subsequently upgraded by a dynamic Pitting Factor. The first case evaluated three, 1959 vintage, non-piggable 40″/38″ telescopic export crude oil pipelines (CR102, CR103 and CR104) with individual corresponding parallel run lengths of 7.7km. All three pipelines run parallel to each other in a common corridor. They are gravity-fed from a storage tank farm resulting in a moderate fluid transit operating velocity. The second assessment was performed on a 6.5 year-old, piggable 36″ crude oil production pipeline (CR088) with an overall distance of 25 kilometers. During the Pre-assessment step, pipeline historical and operational data were collected. Limited historical data was available for the 3 non-piggable pipelines compared to the newer 36″ pipeline which was ultrasonically (UT) inspected via in-line inspection (ILI). In the Indirect Inspection step, the proprietary internal corrosion predictive model (ICPM), enpICDATM, was applied with a uniform Pitting Factor to predict the amount of degradation at those locations where liquid hold-up, solids accumulation, and in-turn the internal metal losses would be most pronounced. During the Detailed Examination step, “in-the-ditch” UT was utilized to measure and confirm the remaining wall thicknesses of the three gravity pipelines whereas a comparison of the ICPM to the ILI was executed for the newer 36″ × 25km pipeline. In the Post-Assessment step, a comparison between the predicted metal losses and the UT-ILI measured data were carried out. As a result of a gap analysis, dynamic Pitting Factors were proposed and developed to enhance and update the proprietary model for predicting the metal losses point-by-point within each subregion over the entire pipeline in terms of local pressure, temperature, water accumulation, and solids deposition. Validation of the in-house prediction was performed using the field measurements for gravity pipelines and ILI data for CR088, demonstrating that metal losses predicted by the proprietary model and measured through field tests and ILI data agree reasonably well for both extreme scenarios. Results showed that three gravity pipelines have minimal internal corrosion under a high flow velocity despite having a 51-year operating history whereas severe internal corrosion was identified after a 6.5-year operation for the CR088 pipeline. Hence, selection of a proper operating velocity is crucial for crude oil pipeline operations. Under a low speed condition, localized Pitting corrosion dominates whereas uniform corrosion is predominant under a higher flow or “sweep” velocity. Since the pipeline operators were more interested in the worst-case scenarios, i.e. metal loss due to localized Pitting corrosion, development of dynamic Pitting Factors was undoubtedly an innovative improvement of the overall Liquid Petroleum - Internal Corrosion Direct Assessment through capturing the fluctuation of metal losses along the entire pipeline, which can enhance the ICDA methodology toward a higher level of precision and accuracy.Copyright © 2012 by ASME

  • two contrasting internal corrosion scenarios assessed by liquid petroleum internal corrosion direct assessment lp icda for the innovative development of a dynamic Pitting Factor
    2012 9th International Pipeline Conference, 2012
    Co-Authors: Patrick J. Teevens, Zhenjin Zhu, Ashish Khera, Abdul Wahab Almithin, Shabbir Safri
    Abstract:

    This paper details the complete four-step Liquid Petroleum - Internal Corrosion Direct Assessment (LP-ICDA) for two operationally different liquid petroleum pipeline systems owned by Kuwait Oil Company. The internal corrosion pipeline wall metal losses were originally predicted using a uniform Pitting Factor and subsequently upgraded by a dynamic Pitting Factor. The first case evaluated three, 1959 vintage, non-piggable 40″/38″ telescopic export crude oil pipelines (CR102, CR103 and CR104) with individual corresponding parallel run lengths of 7.7km. All three pipelines run parallel to each other in a common corridor. They are gravity-fed from a storage tank farm resulting in a moderate fluid transit operating velocity. The second assessment was performed on a 6.5 year-old, piggable 36″ crude oil production pipeline (CR088) with an overall distance of 25 kilometers. During the Pre-assessment step, pipeline historical and operational data were collected. Limited historical data was available for the 3 non-piggable pipelines compared to the newer 36″ pipeline which was ultrasonically (UT) inspected via in-line inspection (ILI). In the Indirect Inspection step, the proprietary internal corrosion predictive model (ICPM), enpICDATM, was applied with a uniform Pitting Factor to predict the amount of degradation at those locations where liquid hold-up, solids accumulation, and in-turn the internal metal losses would be most pronounced. During the Detailed Examination step, “in-the-ditch” UT was utilized to measure and confirm the remaining wall thicknesses of the three gravity pipelines whereas a comparison of the ICPM to the ILI was executed for the newer 36″ × 25km pipeline. In the Post-Assessment step, a comparison between the predicted metal losses and the UT-ILI measured data were carried out. As a result of a gap analysis, dynamic Pitting Factors were proposed and developed to enhance and update the proprietary model for predicting the metal losses point-by-point within each subregion over the entire pipeline in terms of local pressure, temperature, water accumulation, and solids deposition. Validation of the in-house prediction was performed using the field measurements for gravity pipelines and ILI data for CR088, demonstrating that metal losses predicted by the proprietary model and measured through field tests and ILI data agree reasonably well for both extreme scenarios. Results showed that three gravity pipelines have minimal internal corrosion under a high flow velocity despite having a 51-year operating history whereas severe internal corrosion was identified after a 6.5-year operation for the CR088 pipeline. Hence, selection of a proper operating velocity is crucial for crude oil pipeline operations. Under a low speed condition, localized Pitting corrosion dominates whereas uniform corrosion is predominant under a higher flow or “sweep” velocity. Since the pipeline operators were more interested in the worst-case scenarios, i.e. metal loss due to localized Pitting corrosion, development of dynamic Pitting Factors was undoubtedly an innovative improvement of the overall Liquid Petroleum - Internal Corrosion Direct Assessment through capturing the fluctuation of metal losses along the entire pipeline, which can enhance the ICDA methodology toward a higher level of precision and accuracy.Copyright © 2012 by ASME

Richard Gagne - One of the best experts on this subject based on the ideXlab platform.

  • Distribution of corrosion and Pitting Factor of steel in corroded RC beams
    Construction and Building Materials, 2015
    Co-Authors: Raoul François, Vu Hiep Dang, Valerie L'hostis, Richard Gagne
    Abstract:

    The purpose of this work was to study the corrosion distribution along a steel bar in beams of sizes typically used in the construction industry and the ratio between maximum cross-sectional loss and average cross-sectional loss of the steel bar. This work was based on three beams exposed to accelerated natural corrosion for 19-36 months. The cracking maps and crack widths were recorded. After the steel bars had been extracted from the beams and cleaned with Clarke's solution, cross-sectional losses were measured. The experimental results show that average cross-sectional loss of the steel bar correlated well with maximum corrosion crack width. The Pitting Factors of steel bars were mainly between 2.5 and 5.0, and decreased with the increase of average cross-sectional loss. More measurements would be desirable in further research on the Pitting Factor before this Factor is used for predicting the residual mechanical performance of corroded structures. (C) 2015 Elsevier Ltd. All rights reserved.

  • Distribution of corrosion and Pitting Factor of steel in corroded RC beams
    Construction and Building Materials, 2015
    Co-Authors: Raoul François, Vu Hiep Dang, Valérie L’hostis, Richard Gagne
    Abstract:

    Abstract The purpose of this work was to study the corrosion distribution along a steel bar in beams of sizes typically used in the construction industry and the ratio between maximum cross-sectional loss and average cross-sectional loss of the steel bar. This work was based on three beams exposed to accelerated natural corrosion for 19–36 months. The cracking maps and crack widths were recorded. After the steel bars had been extracted from the beams and cleaned with Clarke’s solution, cross-sectional losses were measured. The experimental results show that average cross-sectional loss of the steel bar correlated well with maximum corrosion crack width. The Pitting Factors of steel bars were mainly between 2.5 and 5.0, and decreased with the increase of average cross-sectional loss. More measurements would be desirable in further research on the Pitting Factor before this Factor is used for predicting the residual mechanical performance of corroded structures.