Raoul François | INSA Toulouse (original) (raw)
Papers by Raoul François
European Journal of Environmental and Civil Engineering, 2009
Advances in the study of prestressed precast beams include the response of existing structures un... more Advances in the study of prestressed precast beams include the response of existing structures undergoing deterioration. The paper describes the behaviour of corroding prestressed structures, presenting a review of experimental results on the effects of corrosion on the prestressing reinforcement and the bond of corroded 7-wire strands in concrete. A numerical finite element model for the structural response of beams
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Modelling of Corroding Concrete Structures, 2011
... Arnaud Castel1, Dario Coronelli2, Raoul François1 and David Cleland3 ... C. Andrade and G. Ma... more ... Arnaud Castel1, Dario Coronelli2, Raoul François1 and David Cleland3 ... C. Andrade and G. Mancini (eds.), Modelling of Corroding Concrete Structures, RILEM Bookseries 5, DOI 10.1007/978-94-007-0677-4_15, © RILEM 2011 219 Page 2. Arnaud Castel et al. 220 ...
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Modelling of Corroding Concrete Structures, 2011
Abstract. This paper presents both experimental results and modelling of a highly corroded beam s... more Abstract. This paper presents both experimental results and modelling of a highly corroded beam subjected to chloride environment to assess the performance of long-term corrosion damaged beams. A 26 year old corroded reinforced concrete beam exposed to chloride ...
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Magazine of Concrete Research, 2011
ABSTRACT This paper deals with the influence of the steel-concrete interface condition on the rei... more ABSTRACT This paper deals with the influence of the steel-concrete interface condition on the reinforcement corrosion in a chloride environment. Two large-sized concrete members were cast including horizontal reinforcements at different levels in order to create voids under the upper horizontal bars caused by the well-known `top-bar effect'. The walls were then sawn into small-sized specimens including one rebar. These small specimens were submitted to wetting-drying cycles in salt water (natural corrosion process). The polarisation resistance technique was performed to monitor the steel corrosion during the ageing up to 55 weeks. Chloride profiles were regularly measured and specimens were broken to observe the corrosion pattern. Results show that, first, a good-quality steel-concrete interface significantly reduces the corrosion rate in comparison with the specimen with interfacial defects. Second, before concrete cracking, the corrosion pattern observed is completely different between the specimens with or without defect. Perfect interface specimens show a typical local pitting corrosion pattern owing to chloride attack. However, specimens affected by the `top-bar effect' show a generalised corrosion along the steel surface affected by the void (surface under the horizontal steel bars in regard to concrete casting direction). Macrocell corrosion seems to develop between the lower surface affected by the void acting as an anode and the upper surface where the bond is perfect as the cathode. The concrete cracking is delayed for specimens affected by the `top-bar effect' in spite of a higher corrosion rate. This delay can be attributed to the time necessary for the rust to fill the voids.
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Advances in Structures, Pts 1-5, 2011
... In addition, it is well-known that the Raman technique is used to analyze the compound in a v... more ... In addition, it is well-known that the Raman technique is used to analyze the compound in a very local area, which much depended on ... [4] WJ Chitty, P. Dillmann, V. L'Hostis, C. Lombard: Corrosion Science, 47(2005), pp 1555-1581 [5] Wong HS, Zhao YX, Karimi AR, Buenfeld ...
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European Journal of Environmental and Civil Engineering, 2012
Corrosion is one of the major problems that the reinforced concrete industry is facing nowadays. ... more Corrosion is one of the major problems that the reinforced concrete industry is facing nowadays. Much research has been carried out to investigate the influence of cracks on rebar corrosion. In this project ring shaped mortar samples with an 8mm steel bar inside were cracked with different crack widths and then subjected to continuous wetting and drying cycles in salt
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European Journal of Environmental and Civil Engineering, 2012
This article presents experimental results and the modelling of a highly corroded beam subjected ... more This article presents experimental results and the modelling of a highly corroded beam subjected to a chloride environment to assess the performance of long-term-corrosion-damaged beams. A reinforced concrete beam corroded by 26 years of exposure to a chloride environment was tested until failure, as was a control beam of the same age. Cracking maps and corrosion maps were drawn for
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Proceedings of the Institution of Civil Engineers-Structures and Buildings, 2012
ABSTRACT Deterioration of post-tensioned structures may take place as a consequence of severe env... more ABSTRACT Deterioration of post-tensioned structures may take place as a consequence of severe environmental conditions or design or construction errors. This paper investigates analytically the effects of corrosion on the structural response of bonded post-tensioned beams. An experimental study on the stress corrosion of prestressing wires is described first, providing data on the steel behaviour. A series of tests on beams taken from the literature is then analysed. The breaking of a part of the wires was caused by artificial corrosion; the beams showed stiffness and strength deterioration as a consequence of further breakages occurring under imposed load. Two different analytical approaches are used: macro finite-element analysis based on the calculation of the cross-section response and nonlinear finite-element analysis. The analyses provide the global response and local strain values with the interpretation of the causes of the deterioration of the response.
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European Journal of Environmental and Civil Engineering, 2012
This article deals with the influence of the steel–concrete interface condition on reinforcement ... more This article deals with the influence of the steel–concrete interface condition on reinforcement corrosion and concrete cracking in a chloride environment. Four large concrete members were cast with horizontal reinforcements at different levels in order to create voids under the upper horizontal bars due to the well-known ‘top-bar effect.’ Then, the members were sawn into smaller specimens that included one
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Revue Française de Génie Civil, 1998
This paper deals with the strategy of service-life prediction of reinforced concrete structures. ... more This paper deals with the strategy of service-life prediction of reinforced concrete structures. This strategy which is based on a model of the reinforcement corrosion process, can be used alone to calculate the residual service-life or linked with maintenance method to increase this service life.
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Materials and Structures, 1998
This paper deals with the effect of loading on the microstructure of reinforced high performance ... more This paper deals with the effect of loading on the microstructure of reinforced high performance and normal concrete. In the case of reinforced concrete structures, cracking is the only visible sign of mechanical degradation and is accompanied by microscopic damage to the concrete. To account for this damage, experiments on three different concretes with compressive strengths (f c28) of 45 MPa, 80 MPa and 100 MPa were carried out. The loadless initial state of concrete and the damage state after loading were described using the single replica technique observed on SEM. The way in which the microcracks extended was revealed, with predominantly aggregated bond failure and crack branching occurring with cracks spreading out around the coarse aggregate under stable progressive fracture conditions. An increase in the specific area of microcracks was seen to result from an increase in load. This phenomenon could have an influence on the durability properties of reinforced concrete structures.
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Materials and Structures, 1993
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Materials and Structures, 1997
This paper deals with the effect of the leaching process of cement-based materials on their mecha... more This paper deals with the effect of the leaching process of cement-based materials on their mechanical properties. This process mainly induces a total leaching of Ca(OH)2 and a progressive decalcification of the C-S-H leading in turn to a gradient of C/S ratio in the leaching zone. Modeling of the deterioration of cement paste exposed to leaching consists of a decrease
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Materials and Structures, 2000
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Materials and Structures, 2009
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Materials and Structures, 2007
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Materials and Structures, 2007
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Materials and Structures, 2005
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Materials and Structures, 2009
ABSTRACT
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Materials and Structures, 2011
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European Journal of Environmental and Civil Engineering, 2009
Advances in the study of prestressed precast beams include the response of existing structures un... more Advances in the study of prestressed precast beams include the response of existing structures undergoing deterioration. The paper describes the behaviour of corroding prestressed structures, presenting a review of experimental results on the effects of corrosion on the prestressing reinforcement and the bond of corroded 7-wire strands in concrete. A numerical finite element model for the structural response of beams
Bookmarks Related papers MentionsView impact
Modelling of Corroding Concrete Structures, 2011
... Arnaud Castel1, Dario Coronelli2, Raoul François1 and David Cleland3 ... C. Andrade and G. Ma... more ... Arnaud Castel1, Dario Coronelli2, Raoul François1 and David Cleland3 ... C. Andrade and G. Mancini (eds.), Modelling of Corroding Concrete Structures, RILEM Bookseries 5, DOI 10.1007/978-94-007-0677-4_15, © RILEM 2011 219 Page 2. Arnaud Castel et al. 220 ...
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Modelling of Corroding Concrete Structures, 2011
Abstract. This paper presents both experimental results and modelling of a highly corroded beam s... more Abstract. This paper presents both experimental results and modelling of a highly corroded beam subjected to chloride environment to assess the performance of long-term corrosion damaged beams. A 26 year old corroded reinforced concrete beam exposed to chloride ...
Bookmarks Related papers MentionsView impact
Magazine of Concrete Research, 2011
ABSTRACT This paper deals with the influence of the steel-concrete interface condition on the rei... more ABSTRACT This paper deals with the influence of the steel-concrete interface condition on the reinforcement corrosion in a chloride environment. Two large-sized concrete members were cast including horizontal reinforcements at different levels in order to create voids under the upper horizontal bars caused by the well-known `top-bar effect'. The walls were then sawn into small-sized specimens including one rebar. These small specimens were submitted to wetting-drying cycles in salt water (natural corrosion process). The polarisation resistance technique was performed to monitor the steel corrosion during the ageing up to 55 weeks. Chloride profiles were regularly measured and specimens were broken to observe the corrosion pattern. Results show that, first, a good-quality steel-concrete interface significantly reduces the corrosion rate in comparison with the specimen with interfacial defects. Second, before concrete cracking, the corrosion pattern observed is completely different between the specimens with or without defect. Perfect interface specimens show a typical local pitting corrosion pattern owing to chloride attack. However, specimens affected by the `top-bar effect' show a generalised corrosion along the steel surface affected by the void (surface under the horizontal steel bars in regard to concrete casting direction). Macrocell corrosion seems to develop between the lower surface affected by the void acting as an anode and the upper surface where the bond is perfect as the cathode. The concrete cracking is delayed for specimens affected by the `top-bar effect' in spite of a higher corrosion rate. This delay can be attributed to the time necessary for the rust to fill the voids.
Bookmarks Related papers MentionsView impact
Advances in Structures, Pts 1-5, 2011
... In addition, it is well-known that the Raman technique is used to analyze the compound in a v... more ... In addition, it is well-known that the Raman technique is used to analyze the compound in a very local area, which much depended on ... [4] WJ Chitty, P. Dillmann, V. L'Hostis, C. Lombard: Corrosion Science, 47(2005), pp 1555-1581 [5] Wong HS, Zhao YX, Karimi AR, Buenfeld ...
Bookmarks Related papers MentionsView impact
European Journal of Environmental and Civil Engineering, 2012
Corrosion is one of the major problems that the reinforced concrete industry is facing nowadays. ... more Corrosion is one of the major problems that the reinforced concrete industry is facing nowadays. Much research has been carried out to investigate the influence of cracks on rebar corrosion. In this project ring shaped mortar samples with an 8mm steel bar inside were cracked with different crack widths and then subjected to continuous wetting and drying cycles in salt
Bookmarks Related papers MentionsView impact
European Journal of Environmental and Civil Engineering, 2012
This article presents experimental results and the modelling of a highly corroded beam subjected ... more This article presents experimental results and the modelling of a highly corroded beam subjected to a chloride environment to assess the performance of long-term-corrosion-damaged beams. A reinforced concrete beam corroded by 26 years of exposure to a chloride environment was tested until failure, as was a control beam of the same age. Cracking maps and corrosion maps were drawn for
Bookmarks Related papers MentionsView impact
Proceedings of the Institution of Civil Engineers-Structures and Buildings, 2012
ABSTRACT Deterioration of post-tensioned structures may take place as a consequence of severe env... more ABSTRACT Deterioration of post-tensioned structures may take place as a consequence of severe environmental conditions or design or construction errors. This paper investigates analytically the effects of corrosion on the structural response of bonded post-tensioned beams. An experimental study on the stress corrosion of prestressing wires is described first, providing data on the steel behaviour. A series of tests on beams taken from the literature is then analysed. The breaking of a part of the wires was caused by artificial corrosion; the beams showed stiffness and strength deterioration as a consequence of further breakages occurring under imposed load. Two different analytical approaches are used: macro finite-element analysis based on the calculation of the cross-section response and nonlinear finite-element analysis. The analyses provide the global response and local strain values with the interpretation of the causes of the deterioration of the response.
Bookmarks Related papers MentionsView impact
European Journal of Environmental and Civil Engineering, 2012
This article deals with the influence of the steel–concrete interface condition on reinforcement ... more This article deals with the influence of the steel–concrete interface condition on reinforcement corrosion and concrete cracking in a chloride environment. Four large concrete members were cast with horizontal reinforcements at different levels in order to create voids under the upper horizontal bars due to the well-known ‘top-bar effect.’ Then, the members were sawn into smaller specimens that included one
Bookmarks Related papers MentionsView impact
Revue Française de Génie Civil, 1998
This paper deals with the strategy of service-life prediction of reinforced concrete structures. ... more This paper deals with the strategy of service-life prediction of reinforced concrete structures. This strategy which is based on a model of the reinforcement corrosion process, can be used alone to calculate the residual service-life or linked with maintenance method to increase this service life.
Bookmarks Related papers MentionsView impact
Materials and Structures, 1998
This paper deals with the effect of loading on the microstructure of reinforced high performance ... more This paper deals with the effect of loading on the microstructure of reinforced high performance and normal concrete. In the case of reinforced concrete structures, cracking is the only visible sign of mechanical degradation and is accompanied by microscopic damage to the concrete. To account for this damage, experiments on three different concretes with compressive strengths (f c28) of 45 MPa, 80 MPa and 100 MPa were carried out. The loadless initial state of concrete and the damage state after loading were described using the single replica technique observed on SEM. The way in which the microcracks extended was revealed, with predominantly aggregated bond failure and crack branching occurring with cracks spreading out around the coarse aggregate under stable progressive fracture conditions. An increase in the specific area of microcracks was seen to result from an increase in load. This phenomenon could have an influence on the durability properties of reinforced concrete structures.
Bookmarks Related papers MentionsView impact
Materials and Structures, 1993
Bookmarks Related papers MentionsView impact
Materials and Structures, 1997
This paper deals with the effect of the leaching process of cement-based materials on their mecha... more This paper deals with the effect of the leaching process of cement-based materials on their mechanical properties. This process mainly induces a total leaching of Ca(OH)2 and a progressive decalcification of the C-S-H leading in turn to a gradient of C/S ratio in the leaching zone. Modeling of the deterioration of cement paste exposed to leaching consists of a decrease
Bookmarks Related papers MentionsView impact
Materials and Structures, 2000
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Materials and Structures, 2009
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Materials and Structures, 2007
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Materials and Structures, 2007
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Materials and Structures, 2005
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Materials and Structures, 2009
ABSTRACT
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Materials and Structures, 2011
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