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S. Joiret - One of the best experts on this subject based on the ideXlab platform.
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efficiency investigations of electrochemical realkalisation treatment applied to carbonated reinforced concrete part 1 sacrificial anode process
Cement and Concrete Research, 2012Co-Authors: Yun Yun Tong, Véronique Bouteiller, Elisabeth Marievictoire, S. JoiretAbstract:Abstract The aim of this study was to assess the efficiency of a realkalisation treatment using sacrificial anodes applied to reinforced concrete degraded by carbonation. Analytical determinations (acid/base indicators, quantitative pH, alkaline profiles, SEM and micro-Raman) together with electrochemical characterizations (rest potential, impedance, Linear Polarisation Resistance and corrosion current densities) were performed on artificially carbonated slabs, before and after treatment (mainly 15 days, 11 weeks, 6 and 12 months). The treatment efficiency was demonstrated by an increase of pH and by an alkaline ion penetration in the concrete cover. Rest potential and corrosion current densities indicated a slight decrease of the rebar corrosion activity. Complementary Raman spectroscopy showed a change in the oxide species and SEM observations indicated that the cement matrix remained almost unchanged.
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Efficiency investigations of electrochemical realkalisation treatment applied to carbonated reinforced concrete - Part 1: Sacrificial anode process
Cement and Concrete Research, 2012Co-Authors: Tong Yun Yun, Bouteiller Véronique, Marie-victoire Elisabeth, S. JoiretAbstract:The aim of this study was to assess the efficiency of a realkalisation treatment using sacrificial anodes applied to reinforced concrete degraded by carbonation. Analytical determinations (acid/base indicators, quantitative pH, alkaline profiles, SEM and micro-Raman) together with electrochemical characterizations (rest potential, impedance, Linear Polarisation Resistance and corrosion current densities) were performed on artificially carbonated slabs, before and after treatment (mainly 15 days, 11 weeks, 6 and 12 months). The treatment efficiency was demonstrated by an increase of pH and by an alkaline ion penetration in the concrete cover. Rest potential and corrosion current densities indicated a slight decrease of the rebar corrosion activity. Complementary Raman spectroscopy showed a change in the oxide species and SEM observations indicated that the cement matrix remained almost unchanged. (C) 2011 Elsevier Ltd. All rights reserved.
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Efficiency investigations of electrochemical realkalisation treatment applied to carbonated reinforced concrete — Part 1: Sacrificial anode process
Cement and Concrete Research, 2011Co-Authors: Yun Yun Tong, Véronique Bouteiller, Elisabeth Marie-victoire, S. JoiretAbstract:Abstract The aim of this study was to assess the efficiency of a realkalisation treatment using sacrificial anodes applied to reinforced concrete degraded by carbonation. Analytical determinations (acid/base indicators, quantitative pH, alkaline profiles, SEM and micro-Raman) together with electrochemical characterizations (rest potential, impedance, Linear Polarisation Resistance and corrosion current densities) were performed on artificially carbonated slabs, before and after treatment (mainly 15 days, 11 weeks, 6 and 12 months). The treatment efficiency was demonstrated by an increase of pH and by an alkaline ion penetration in the concrete cover. Rest potential and corrosion current densities indicated a slight decrease of the rebar corrosion activity. Complementary Raman spectroscopy showed a change in the oxide species and SEM observations indicated that the cement matrix remained almost unchanged.
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Electrochemical realkalisation of carbonated reinforced concrete using impressed current or sacrificial anodes 2.5 years durability
2009Co-Authors: Yun Yun Tong, Véronique Bouteiller, S. Joiret, Elisabeth Marie VictoireAbstract:The aim of this study is to assess the durability of the efficiency of an electrochemical realkalisation treatment applied on artificially carbonated reinforced concrete slabs. Realkalisation based on impressed current as well as sacrificial anodes was tested. The slabs were firstly stored in the laboratory for 18 months after treatment and then they were exposed for 12 additional months to natural ageing. Analytical characterizations (phenolphthalein and thymolphthalein color indicators, quantitative pH, SEM combined to EDS) and electrochemical characterizations (rest potential, Linear Polarisation Resistance and impedance) were performed, before realkalisation and until 30 months after treatment in order to determine the efficiency of the two treatments, their eventual side effects and their durability.
Véronique Bouteiller - One of the best experts on this subject based on the ideXlab platform.
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Evolution of reinforced concrete prism corrosion with time depending on degradation types and exposition conditions
2012Co-Authors: Véronique Bouteiller, Elisabeth Marie-victoire, Jean-françois Cherrier, Bruno Koubi, Umair Iftikhar, Valérie L'hostis, Julien Schneider, Nuria Rebolledo, Carmen AndradeAbstract:Corrosion is one of the major durability problems that needs to be solve in order to extend the service life of a reinforced concrete structure. Within the APPLET project, in order to evaluate corrosion kinetics, the influences of both the concrete (sound or polluted) and the environmental conditions (controlled or outdoor) were studied. Four series of reinforced concrete prisms were made and aged depending on the degradation: none, chlorides in the mix, chlorides by wetting/drying cycles and carbonation. They were then exposed to seven environmental conditions based on different Temperature - Relative Humidity couples among them the natural outdoor weathering condition. Electrochemical characterizations (half-cell potential, Linear Polarisation Resistance and corrosion rate) were carried on for each of the 140 prisms four times a year for more than 3 years. A database of more than 3000 values was delivered. Results were discussed based on different parameters such as degradation type, temperature, humidity and time.
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Influence of humidity and temperature on the corrosion of reinforced concrete prisms
European Journal of Environmental and Civil Engineering, 2012Co-Authors: Véronique Bouteiller, Jean-françois Cherrier, Nuria Rebolledo, Carmen Andrade, Valérie L’hostis, Elisabeth Marie VictoireAbstract:Reinforcement corrosion is one of the major durability problems that need to be solved in order to extend the service life of a structure. It is influenced, on one hand, by the concrete itself, sound or polluted (chlorinated or carbonated), and on the other hand, by the environmental conditions (controlled or outdoor). To explore the influence of temperature and humidity, electrochemical characterisations (potential, Linear Polarisation Resistance and corrosion rate) were carried out on reinforced concrete prisms. A database of more than 3000 values has been delivered. The results enabled us to deduce that both parameters have influences on each other. Moreover, considering the four concretes, the corrosion order obtained in controlled conditions may be different from the one obtained in outdoor conditions. La corrosion des armatures est un probleme majeur dans la durabilite du beton qui doit etre resolu afin d’augmenter la duree de vie des structures. Elle depend, d’une part, de la nature du beton (sain ...
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efficiency investigations of electrochemical realkalisation treatment applied to carbonated reinforced concrete part 1 sacrificial anode process
Cement and Concrete Research, 2012Co-Authors: Yun Yun Tong, Véronique Bouteiller, Elisabeth Marievictoire, S. JoiretAbstract:Abstract The aim of this study was to assess the efficiency of a realkalisation treatment using sacrificial anodes applied to reinforced concrete degraded by carbonation. Analytical determinations (acid/base indicators, quantitative pH, alkaline profiles, SEM and micro-Raman) together with electrochemical characterizations (rest potential, impedance, Linear Polarisation Resistance and corrosion current densities) were performed on artificially carbonated slabs, before and after treatment (mainly 15 days, 11 weeks, 6 and 12 months). The treatment efficiency was demonstrated by an increase of pH and by an alkaline ion penetration in the concrete cover. Rest potential and corrosion current densities indicated a slight decrease of the rebar corrosion activity. Complementary Raman spectroscopy showed a change in the oxide species and SEM observations indicated that the cement matrix remained almost unchanged.
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Efficiency investigations of electrochemical realkalisation treatment applied to carbonated reinforced concrete — Part 1: Sacrificial anode process
Cement and Concrete Research, 2011Co-Authors: Yun Yun Tong, Véronique Bouteiller, Elisabeth Marie-victoire, S. JoiretAbstract:Abstract The aim of this study was to assess the efficiency of a realkalisation treatment using sacrificial anodes applied to reinforced concrete degraded by carbonation. Analytical determinations (acid/base indicators, quantitative pH, alkaline profiles, SEM and micro-Raman) together with electrochemical characterizations (rest potential, impedance, Linear Polarisation Resistance and corrosion current densities) were performed on artificially carbonated slabs, before and after treatment (mainly 15 days, 11 weeks, 6 and 12 months). The treatment efficiency was demonstrated by an increase of pH and by an alkaline ion penetration in the concrete cover. Rest potential and corrosion current densities indicated a slight decrease of the rebar corrosion activity. Complementary Raman spectroscopy showed a change in the oxide species and SEM observations indicated that the cement matrix remained almost unchanged.
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Electrochemical realkalisation of carbonated reinforced concrete using impressed current or sacrificial anodes 2.5 years durability
2009Co-Authors: Yun Yun Tong, Véronique Bouteiller, S. Joiret, Elisabeth Marie VictoireAbstract:The aim of this study is to assess the durability of the efficiency of an electrochemical realkalisation treatment applied on artificially carbonated reinforced concrete slabs. Realkalisation based on impressed current as well as sacrificial anodes was tested. The slabs were firstly stored in the laboratory for 18 months after treatment and then they were exposed for 12 additional months to natural ageing. Analytical characterizations (phenolphthalein and thymolphthalein color indicators, quantitative pH, SEM combined to EDS) and electrochemical characterizations (rest potential, Linear Polarisation Resistance and impedance) were performed, before realkalisation and until 30 months after treatment in order to determine the efficiency of the two treatments, their eventual side effects and their durability.
Yun Yun Tong - One of the best experts on this subject based on the ideXlab platform.
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efficiency investigations of electrochemical realkalisation treatment applied to carbonated reinforced concrete part 1 sacrificial anode process
Cement and Concrete Research, 2012Co-Authors: Yun Yun Tong, Véronique Bouteiller, Elisabeth Marievictoire, S. JoiretAbstract:Abstract The aim of this study was to assess the efficiency of a realkalisation treatment using sacrificial anodes applied to reinforced concrete degraded by carbonation. Analytical determinations (acid/base indicators, quantitative pH, alkaline profiles, SEM and micro-Raman) together with electrochemical characterizations (rest potential, impedance, Linear Polarisation Resistance and corrosion current densities) were performed on artificially carbonated slabs, before and after treatment (mainly 15 days, 11 weeks, 6 and 12 months). The treatment efficiency was demonstrated by an increase of pH and by an alkaline ion penetration in the concrete cover. Rest potential and corrosion current densities indicated a slight decrease of the rebar corrosion activity. Complementary Raman spectroscopy showed a change in the oxide species and SEM observations indicated that the cement matrix remained almost unchanged.
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Efficiency investigations of electrochemical realkalisation treatment applied to carbonated reinforced concrete — Part 1: Sacrificial anode process
Cement and Concrete Research, 2011Co-Authors: Yun Yun Tong, Véronique Bouteiller, Elisabeth Marie-victoire, S. JoiretAbstract:Abstract The aim of this study was to assess the efficiency of a realkalisation treatment using sacrificial anodes applied to reinforced concrete degraded by carbonation. Analytical determinations (acid/base indicators, quantitative pH, alkaline profiles, SEM and micro-Raman) together with electrochemical characterizations (rest potential, impedance, Linear Polarisation Resistance and corrosion current densities) were performed on artificially carbonated slabs, before and after treatment (mainly 15 days, 11 weeks, 6 and 12 months). The treatment efficiency was demonstrated by an increase of pH and by an alkaline ion penetration in the concrete cover. Rest potential and corrosion current densities indicated a slight decrease of the rebar corrosion activity. Complementary Raman spectroscopy showed a change in the oxide species and SEM observations indicated that the cement matrix remained almost unchanged.
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Electrochemical realkalisation of carbonated reinforced concrete using impressed current or sacrificial anodes 2.5 years durability
2009Co-Authors: Yun Yun Tong, Véronique Bouteiller, S. Joiret, Elisabeth Marie VictoireAbstract:The aim of this study is to assess the durability of the efficiency of an electrochemical realkalisation treatment applied on artificially carbonated reinforced concrete slabs. Realkalisation based on impressed current as well as sacrificial anodes was tested. The slabs were firstly stored in the laboratory for 18 months after treatment and then they were exposed for 12 additional months to natural ageing. Analytical characterizations (phenolphthalein and thymolphthalein color indicators, quantitative pH, SEM combined to EDS) and electrochemical characterizations (rest potential, Linear Polarisation Resistance and impedance) were performed, before realkalisation and until 30 months after treatment in order to determine the efficiency of the two treatments, their eventual side effects and their durability.
Steve Millard - One of the best experts on this subject based on the ideXlab platform.
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Corrosion assessment of reinforced concrete structures in corrosive environments in Chinese chemical industry
British Corrosion Journal, 2013Co-Authors: K. R. Gowers, Wang Dongwei, Li Dawang, Zhao Zhuo, Steve MillardAbstract:AbstractTechniques have been assessed for estimating corrosion in reinforced concrete structures in chemical environments, and measurements have been carried out in the laboratory at the University of Liverpool and at several different chemical factory sites in China and the UK. If it is possible to make a direct contact to the steel reinforcement, then Linear Polarisation Resistance (LPR) measurement is the most suitable technique to employ. Where it is not possible to make contact with the reinforcement, it has been found that concrete resistivity measurement is a better technique in chemical environments for estimating corrosion than potential measurement or mapping.
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Novel method for Linear Polarisation Resistance corrosion measurement
2009Co-Authors: Steve MillardAbstract:Linear Polarisation Resistance (LPR) can provide a direct evaluation of the instantaneous rate of corrosion. However it has the disadvantage of requiring a localised breakout of the concrete cover to provide an electrical connection to the steel reinforcement. This paper describes an adaptation of the LPR method and the four-point Wenner resistivity method to give an evaluation of the rate of steel corrosion without the requirement for a direct electrical connection to the steel reinforcement. Resume La Resistance par Polarisation Lineaire (LPR) peut fournir une evaluation directe du taux instantane de corrosion. Cependant, elle a l'inconvenient de necessiter une breche localisee de la couverture du beton pour fournir une connexion electrique au renfort d'acier. Ce papier decrit une adaptation de la methode LPR et de la methode de resistivite Wenner a quatre points pour evaluer le taux de corrosion de l'acier sans besoin d’une connexion electrique directe au renfort d'acier.
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Field measurements of corrosion rate of steel in reinforced concrete
2006Co-Authors: Steve Millard, D LawAbstract:The corrosion of steel reinforcing bars is one of the biggest problems facing owners of reinforced concrete structures today. Corrosion is initiated by cast-in or ingressing contamination and propagates out of sight until the damage level causes cracking or spalling. Many structure assessment strategies rely on a visual inspection to highlight problem areas. Remediation at this stage is much more costly than earlier preventative action. A more sophisticated strategy can make use of half cell potential mapping to locate regions of corrosion initiation. but this technique gives no evaluation of the severity of the problem. The Linear Polarisation Resistance (LPR) method is a pcrturbativc electrochemical method which can give an evaluation of the instantaneous rate of active corrosion and which is gaining in popularity in Europe, USA and Australia. llowever corrosion is a dynamic process which may fluctuate with changes in the ambient environmental conditions. A corrosion rate measurement on one occasion may not give a representative evaluation of the severity of corrosion problem over an extended period. This paper reports on a continuous study of the Linear Polarisation Resistance method on externally exposed reinforced concrete in the UK to evaluate the etTects of the environment on corrosion rate measurements. The results show how the etTects of temperature and rainfall can influence the measurements and guidelines arc suggested for using LPR to assess corrosion over an extended period.
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Measurement of loss of steel from reinforcing bars in concrete using Linear Polarisation Resistance measurements
Ndt & E International, 2004Co-Authors: D.w. Law, Steve Millard, John Cairns, John H. BungeyAbstract:Abstract The measured weight loss data for a number of mild steel bars contained in Portland Cement concrete, together with predicted weight loss values monitored using potentiostatically controlled Linear Polarisation Resistance (LPR) measurements are reported. Three sets of reinforced concrete specimens, each containing electrically isolated mild steel bars, were subjected to either • chloride-induced corrosion, • carbonation-induced corrosion • a control nitrogen rich environment with minimal corrosion. Each set of specimens was initially exposed to a 22-hour dry, 2-hour wet controlled environment for a duration of between 1026 and 1085 days. This was later changed to a 6-day dry, 1 day wet cycle for the carbonation exposure specimens after the initial set of gravimetric testing. The weight loss for each bar due to corrosion was recorded. Instantaneous LPR measurements were also taken on each bar at regular intervals throughout the exposure period. These Resistance measurements were then integrated over the exposure period to estimate total weight loss. The results show that weight loss evaluated from experimental LPR measurements gives a significant over-estimate of the weight losses measured gravimetrically.
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Measuring the corrosion rate of reinforced concrete using Linear Polarisation Resistance
2003Co-Authors: Steve Millard, John BroomfieldAbstract:Reinforcement corrosion is one of the main causes of reinforced concrete deterioration. Corrosion cannot be visually detected until cracking or rust stains appear at the concrete surface. Timing of repair and renovation are dictated by economics and safety considerations. Information on corrosion rates can give early warning of durability problems to help owners to select appropriate remediation options.
John Cairns - One of the best experts on this subject based on the ideXlab platform.
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Measurement of loss of steel from reinforcing bars in concrete using Linear Polarisation Resistance measurements
Ndt & E International, 2004Co-Authors: D.w. Law, Steve Millard, John Cairns, John H. BungeyAbstract:Abstract The measured weight loss data for a number of mild steel bars contained in Portland Cement concrete, together with predicted weight loss values monitored using potentiostatically controlled Linear Polarisation Resistance (LPR) measurements are reported. Three sets of reinforced concrete specimens, each containing electrically isolated mild steel bars, were subjected to either • chloride-induced corrosion, • carbonation-induced corrosion • a control nitrogen rich environment with minimal corrosion. Each set of specimens was initially exposed to a 22-hour dry, 2-hour wet controlled environment for a duration of between 1026 and 1085 days. This was later changed to a 6-day dry, 1 day wet cycle for the carbonation exposure specimens after the initial set of gravimetric testing. The weight loss for each bar due to corrosion was recorded. Instantaneous LPR measurements were also taken on each bar at regular intervals throughout the exposure period. These Resistance measurements were then integrated over the exposure period to estimate total weight loss. The results show that weight loss evaluated from experimental LPR measurements gives a significant over-estimate of the weight losses measured gravimetrically.
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environmental influences on Linear Polarisation corrosion rate measurement in reinforced concrete
Ndt & E International, 2001Co-Authors: S G Millard, J H Bungey, John CairnsAbstract:Abstract The Linear Polarisation Resistance (LPR) method can be used to measure the active rate of corrosion of steel reinforcement in concrete structures. However a single measurement may be sensitive to the ambient environmental conditions and thus may not be representative of the mean annual rate of corrosion. The LPR measurement may be dependent upon the temperature at the time of sampling and on any wetting/drying effects resulting from rainfall and wind or sunshine. Recent studies have examined the behaviour of a series of reinforced concrete specimens subject to chloride contamination or carbonation induced corrosion in a controlled laboratory environment. LPR measurements taken at frequent intervals have been related to a wet/dry cycle imposed upon the specimens to promote corrosion activity. In addition, similar studies have been carried out, of an in situ reinforced concrete specimen exposed to the ambient weather conditions. The study is only partly completed, but interim results show the variability of LPR measurements and the influences the environment may exert on single spot measurements.