Dépouillements

Dilation behaviour of lime mortars for restoration work / Jean-Didier Mertz in European journal of environmental and civil engineering, Vol. 16 N° 5 (Mai 2012) 

Public ISBD [article]  in European journal of environmental and civil engineering > Vol. 16 N° 5 (Mai 2012) . - pp. 527-542 Titre : Dilation behaviour of lime mortars for restoration work : Application to the compatibility of cracked stone reassembling Type de document : texte imprimé Auteurs : Jean-Didier Mertz, Auteur ; Mikaël Guiavarc’h, Auteur ; Paolo Pagnin, Auteur Année de publication : 2012 Article en page(s) : pp. 527-542 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Hygric  dilation  Thermal  dilation  Cracks  Specific  surface  area  Swelling  clay  Compatibility  Lime  mortar  Injection  grout  Limestones  Archaeological  sites Résumé : A major problem in stone restoration is the reassembling of cracked stones using mortar and grout. The usual criteria for selection of products are related to chemical (free soluble salts), petrophysical and mechanical properties (absorption of water, porosity, elasticity modulus, compressive and traction strength resistance, adherence and hardness). Because in semi-arid environments stones are subjected to high hygric and thermal gradients, current validated solutions could be less durable or unsuitable. Several investigations underline the importance of dilation as a mechanism of damage and stone decay. The set up of a method related to thermal and hygric dilation measurements is presented. Dilation is linked to structural parameters of the materials and represents a significant physical property to assess stone–mortar compatibility. The study has been undertaken for the treatment of cracked limestones from the archaeological sites of Djemila (Algeria) and Volubilis (Morocco). DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.668018 [article] Dilation behaviour of lime mortars for restoration work : Application to the compatibility of cracked stone reassembling [texte imprimé] / Jean-Didier Mertz, Auteur ; Mikaël Guiavarc’h, Auteur ; Paolo Pagnin, Auteur . - 2012 . - pp. 527-542. Génie Civil Langues : Anglais (eng) in European journal of environmental and civil engineering > Vol. 16 N° 5 (Mai 2012) . - pp. 527-542 Mots-clés : Hygric  dilation  Thermal  dilation  Cracks  Specific  surface  area  Swelling  clay  Compatibility  Lime  mortar  Injection  grout  Limestones  Archaeological  sites Résumé : A major problem in stone restoration is the reassembling of cracked stones using mortar and grout. The usual criteria for selection of products are related to chemical (free soluble salts), petrophysical and mechanical properties (absorption of water, porosity, elasticity modulus, compressive and traction strength resistance, adherence and hardness). Because in semi-arid environments stones are subjected to high hygric and thermal gradients, current validated solutions could be less durable or unsuitable. Several investigations underline the importance of dilation as a mechanism of damage and stone decay. The set up of a method related to thermal and hygric dilation measurements is presented. Dilation is linked to structural parameters of the materials and represents a significant physical property to assess stone–mortar compatibility. The study has been undertaken for the treatment of cracked limestones from the archaeological sites of Djemila (Algeria) and Volubilis (Morocco). DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.668018

Application of digital techniques in monument preservation / Xavier Brunetaud in European journal of environmental and civil engineering, Vol. 16 N° 5 (Mai 2012) 

Public ISBD [article]  in European journal of environmental and civil engineering > Vol. 16 N° 5 (Mai 2012) . - pp. 543-556 Titre : Application of digital techniques in monument preservation Type de document : texte imprimé Auteurs : Xavier Brunetaud, Auteur ; Livio De Luca, Auteur ; Sarah Janvier-Badosa, Auteur Année de publication : 2012 Article en page(s) : pp. 543-556 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Conservation  3D  reconstruction  Monument  Mapping  of  deterioration  Stonework  dating Résumé : Health records for monuments are produced to provide a basis for scientific monitoring and planning of restoration work. The collected data (locations of deterioration, and architectural and historical archives) must be referenced in a single documentation platform to establish a detailed diagnosis of the state of degradation of the monument. This paper presents the application of digital techniques for production of a health record of a monument, applied to the castle of Chambord (Loire Valley, France). The first step is to provide a 3D digital reconstruction of the monument. This 3D modelling consists in constructing a finely refined and relevant graphic base to spatially reference all data acquired during the project. Topography is used to precisely locate the relative position of the main architectural components, while photogrammetry can set in detail each of these elements. The application of textures extracted from pictures on surfaces of the 3D model provides a realistic appearance. Additional data from a laser scanner can be included to detail complex forms or specific degraded areas for monitoring or documentation purpose. The state of deterioration of the structure is evaluated through a visual in situ survey. Dating and identification of rocks are determined by searching in the historical and architectural archives that are sometimes incomplete. Finally, the NUBES web-based platform is used to spatially associate data with the 3D model of the monument. This database underpins the health record of the castle of Chambord. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.676365 [article] Application of digital techniques in monument preservation [texte imprimé] / Xavier Brunetaud, Auteur ; Livio De Luca, Auteur ; Sarah Janvier-Badosa, Auteur . - 2012 . - pp. 543-556. Génie Civil Langues : Anglais (eng) in European journal of environmental and civil engineering > Vol. 16 N° 5 (Mai 2012) . - pp. 543-556 Mots-clés : Conservation  3D  reconstruction  Monument  Mapping  of  deterioration  Stonework  dating Résumé : Health records for monuments are produced to provide a basis for scientific monitoring and planning of restoration work. The collected data (locations of deterioration, and architectural and historical archives) must be referenced in a single documentation platform to establish a detailed diagnosis of the state of degradation of the monument. This paper presents the application of digital techniques for production of a health record of a monument, applied to the castle of Chambord (Loire Valley, France). The first step is to provide a 3D digital reconstruction of the monument. This 3D modelling consists in constructing a finely refined and relevant graphic base to spatially reference all data acquired during the project. Topography is used to precisely locate the relative position of the main architectural components, while photogrammetry can set in detail each of these elements. The application of textures extracted from pictures on surfaces of the 3D model provides a realistic appearance. Additional data from a laser scanner can be included to detail complex forms or specific degraded areas for monitoring or documentation purpose. The state of deterioration of the structure is evaluated through a visual in situ survey. Dating and identification of rocks are determined by searching in the historical and architectural archives that are sometimes incomplete. Finally, the NUBES web-based platform is used to spatially associate data with the 3D model of the monument. This database underpins the health record of the castle of Chambord. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.676365

Thermo-hydro-mechanical behaviour of tuffeau stone masonry / Naima Belayachi in European journal of environmental and civil engineering, Vol. 16 N° 5 (Mai 2012) 

Public ISBD [article]  in European journal of environmental and civil engineering > Vol. 16 N° 5 (Mai 2012) . - pp. 557-570 Titre : Thermo-hydro-mechanical behaviour of tuffeau stone masonry Type de document : texte imprimé Auteurs : Naima Belayachi, Auteur ; Dashnor Hoxha, Auteur ; Duc Phi Do, Auteur Année de publication : 2012 Article en page(s) : pp. 557-570 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Thermo-hydro-mechanical  coupling  Effective  stress  Weathering  Stone  Fatigue Résumé : This paper deals with thermo-hydromechanical behaviour of a stone masonry wall assembled with mortar. Macroscopic modelling is proposed that allows an evaluation of the impact of everyday thermal and hydraulic variations on the generation of variations in effective stress. The thermo-hydromechanic parameters of the unsaturated stone have been estimated by experimental tests for tuffeau, such as that found in the Chambord monument. An inverse identification has been used for the optimisation of these parameters based on in- situ measurements, before using the model for long-term analysis. The results of this numerical study show that the contrast between the properties alone is not sufficient to generate a stress that is superior to the stone strength. Otherwise, the variations in thermal and hydraulic conditions on the surface of the stone could lead to a fatigue-like degradation of historic monuments. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.668015 [article] Thermo-hydro-mechanical behaviour of tuffeau stone masonry [texte imprimé] / Naima Belayachi, Auteur ; Dashnor Hoxha, Auteur ; Duc Phi Do, Auteur . - 2012 . - pp. 557-570. Génie Civil Langues : Anglais (eng) in European journal of environmental and civil engineering > Vol. 16 N° 5 (Mai 2012) . - pp. 557-570 Mots-clés : Thermo-hydro-mechanical  coupling  Effective  stress  Weathering  Stone  Fatigue Résumé : This paper deals with thermo-hydromechanical behaviour of a stone masonry wall assembled with mortar. Macroscopic modelling is proposed that allows an evaluation of the impact of everyday thermal and hydraulic variations on the generation of variations in effective stress. The thermo-hydromechanic parameters of the unsaturated stone have been estimated by experimental tests for tuffeau, such as that found in the Chambord monument. An inverse identification has been used for the optimisation of these parameters based on in- situ measurements, before using the model for long-term analysis. The results of this numerical study show that the contrast between the properties alone is not sufficient to generate a stress that is superior to the stone strength. Otherwise, the variations in thermal and hydraulic conditions on the surface of the stone could lead to a fatigue-like degradation of historic monuments. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.668015

Microstructure and mechanical properties of polymer-modified mortars / Sandrine Marceau in European journal of environmental and civil engineering, Vol. 16 N° 5 (Mai 2012) 

Public ISBD [article]  in European journal of environmental and civil engineering > Vol. 16 N° 5 (Mai 2012) . - pp. 571-581 Titre : Microstructure and mechanical properties of polymer-modified mortars Type de document : texte imprimé Auteurs : Sandrine Marceau, Auteur ; Florent Lespinasse, Auteur ; Julien Bellanger, Auteur Année de publication : 2012 Article en page(s) : pp. 571-581 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Repair  product  Polymer  modified  mortars  Latex  Mortar  Repair  Cure Résumé : The influence of the addition of polymer in mortars is investigated with special emphasis on the microstructure and mechanical properties of hardened materials. The presence of polymer in the mortars causes an increase of both the setting time of the cement and the porosity in hardened materials. The observation of these composites by scanning electron microscopy shows the formation of a continuous film of polymer within the matrix for a polymer/cement ratio of 10%. Therefore, the presence of polymer provides a structure where bicontinuous phases of polymer and cement hydrates are intertwined. This leads to a better resistance to acid attack and improves the adhesion between the cement paste and aggregates in mortars. The mechanical properties of composite mortars decrease with the addition of polymer due to the increase of porosity. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.675148 [article] Microstructure and mechanical properties of polymer-modified mortars [texte imprimé] / Sandrine Marceau, Auteur ; Florent Lespinasse, Auteur ; Julien Bellanger, Auteur . - 2012 . - pp. 571-581. Génie Civil Langues : Anglais (eng) in European journal of environmental and civil engineering > Vol. 16 N° 5 (Mai 2012) . - pp. 571-581 Mots-clés : Repair  product  Polymer  modified  mortars  Latex  Mortar  Repair  Cure Résumé : The influence of the addition of polymer in mortars is investigated with special emphasis on the microstructure and mechanical properties of hardened materials. The presence of polymer in the mortars causes an increase of both the setting time of the cement and the porosity in hardened materials. The observation of these composites by scanning electron microscopy shows the formation of a continuous film of polymer within the matrix for a polymer/cement ratio of 10%. Therefore, the presence of polymer provides a structure where bicontinuous phases of polymer and cement hydrates are intertwined. This leads to a better resistance to acid attack and improves the adhesion between the cement paste and aggregates in mortars. The mechanical properties of composite mortars decrease with the addition of polymer due to the increase of porosity. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.675148

Effect of wetting-drying cycles on mortar samples affected by DEF / N. Leklou in European journal of environmental and civil engineering, Vol. 16 N° 5 (Mai 2012) 

Public ISBD [article]  in European journal of environmental and civil engineering > Vol. 16 N° 5 (Mai 2012) . - pp. 582-588 Titre : Effect of wetting-drying cycles on mortar samples affected by DEF Type de document : texte imprimé Auteurs : N. Leklou, Auteur ; J.-E. Aubert, Auteur ; G. Escadeillas, Auteur Année de publication : 2012 Article en page(s) : pp. 582-588 Note générale : Génie Civil Langues : Français (fre) Mots-clés : Wetting-drying  cycles  Microcracks  Scanning  electron  microscopy  (SEM)  Replica  Delayed  ettringite  formation  (DEF)  Expansion Résumé : This article, which deals with the effect of wetting–drying (W-D) cycles on materials affected by delayed ettringite formation (DEF), has two main objectives. The first is to observe whether W-D cycles pre-damage samples, by using the replica technique. Scanning electron microscopy (SEM) observations of replicas show that W-D cycles lead to microcracks in the samples. The second objective of the study is to observe whether the cycles are necessary for development of DEF or if they only accelerate DEF. A study of the expansion of the samples shows that cycles accelerate the appearance of expansion but they are not a prerequisite for triggering DEF. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.668017 [article] Effect of wetting-drying cycles on mortar samples affected by DEF [texte imprimé] / N. Leklou, Auteur ; J.-E. Aubert, Auteur ; G. Escadeillas, Auteur . - 2012 . - pp. 582-588. Génie Civil Langues : Français (fre) in European journal of environmental and civil engineering > Vol. 16 N° 5 (Mai 2012) . - pp. 582-588 Mots-clés : Wetting-drying  cycles  Microcracks  Scanning  electron  microscopy  (SEM)  Replica  Delayed  ettringite  formation  (DEF)  Expansion Résumé : This article, which deals with the effect of wetting–drying (W-D) cycles on materials affected by delayed ettringite formation (DEF), has two main objectives. The first is to observe whether W-D cycles pre-damage samples, by using the replica technique. Scanning electron microscopy (SEM) observations of replicas show that W-D cycles lead to microcracks in the samples. The second objective of the study is to observe whether the cycles are necessary for development of DEF or if they only accelerate DEF. A study of the expansion of the samples shows that cycles accelerate the appearance of expansion but they are not a prerequisite for triggering DEF. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.668017

Effects of early-age thermal behaviour on damage risks in massive concrete structures / Matthieu Briffaut in European journal of environmental and civil engineering, Vol. 16 N° 5 (Mai 2012) 

Public ISBD [article]  in European journal of environmental and civil engineering > Vol. 16 N° 5 (Mai 2012) . - pp. 589-605 Titre : Effects of early-age thermal behaviour on damage risks in massive concrete structures Type de document : texte imprimé Auteurs : Matthieu Briffaut, Auteur ; Benboudjema, Farid, Auteur ; Torrenti, Jean-Michel, Auteur Année de publication : 2012 Article en page(s) : pp. 589-605 Note générale : Génie Civil Langues : Français (fre) Mots-clés : Early  age  Thermal  properties  Concrete  Massive  structures Résumé : At early age, temperature in massive concrete structures may reach over 70°C because hydration is an exothermic chemical reaction. Temperature evolution (increasing followed by decreasing temperature) can lead to damage risks in the short and long term. Firstly, cracking due to self-restrained strains (essentially thermal strains) can occur (which increase the transport properties and so the kinetics of degradation); and secondly, delayed ettringite formation can appear. In addition, if autogenous and thermal strains are restrained, compressive stresses and then tensile stresses increase, which can cause crossing cracks. However, this paper will not deal with these phenomena. In the first part, sensitivity to delayed ettringite formation and early age cracks by self-restrained strains are studied with regards to the environmental conditions by a numerical approach. This part shows that the external temperature has a significant impact on the maximal temperature reached, but that the temperature difference between the core and the surface is mainly impacted by the wind velocity. Then, a parametric study on the effect of the variation of thermal properties at early age has been achieved and shows that it needs to be taken into account. Finally, visco-elastic mechanical calculations show the impact of thermal property variation on the stresses generated by self restraint. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.668016 [article] Effects of early-age thermal behaviour on damage risks in massive concrete structures [texte imprimé] / Matthieu Briffaut, Auteur ; Benboudjema, Farid, Auteur ; Torrenti, Jean-Michel, Auteur . - 2012 . - pp. 589-605. Génie Civil Langues : Français (fre) in European journal of environmental and civil engineering > Vol. 16 N° 5 (Mai 2012) . - pp. 589-605 Mots-clés : Early  age  Thermal  properties  Concrete  Massive  structures Résumé : At early age, temperature in massive concrete structures may reach over 70°C because hydration is an exothermic chemical reaction. Temperature evolution (increasing followed by decreasing temperature) can lead to damage risks in the short and long term. Firstly, cracking due to self-restrained strains (essentially thermal strains) can occur (which increase the transport properties and so the kinetics of degradation); and secondly, delayed ettringite formation can appear. In addition, if autogenous and thermal strains are restrained, compressive stresses and then tensile stresses increase, which can cause crossing cracks. However, this paper will not deal with these phenomena. In the first part, sensitivity to delayed ettringite formation and early age cracks by self-restrained strains are studied with regards to the environmental conditions by a numerical approach. This part shows that the external temperature has a significant impact on the maximal temperature reached, but that the temperature difference between the core and the surface is mainly impacted by the wind velocity. Then, a parametric study on the effect of the variation of thermal properties at early age has been achieved and shows that it needs to be taken into account. Finally, visco-elastic mechanical calculations show the impact of thermal property variation on the stresses generated by self restraint. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.668016

Influence of the spatial variability of leaching kinetics parameters on the lifespan of a concrete structure / Thomas de Larrard in European journal of environmental and civil engineering, Vol. 16 N° 5 (Mai 2012) 

Public ISBD [article]  in European journal of environmental and civil engineering > Vol. 16 N° 5 (Mai 2012) . - pp. 606-624 Titre : Influence of the spatial variability of leaching kinetics parameters on the lifespan of a concrete structure Type de document : texte imprimé Auteurs : Thomas de Larrard, Auteur ; Benboudjema, Farid, Auteur ; Jean-Baptiste Colliat, Auteur Année de publication : 2012 Article en page(s) : pp. 606-624 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Leaching  Porosity  Tortuosity  Variability  Distribution  Correlation  length  Karhunen--Loève  expansion  Monte  Carlo  method Résumé : This works aims at studying, through the Monte Carlo method, the influence of the leaching kinetics parameters spatial variability on the lifespan of a concrete structure. The considered structure is a tunnel for nuclear waste storage. It is observed that the expected value for the lifespan estimated when considering the material spatial variability is significantly lower than the lifespan estimated with a single simulation considering uniform parameter fields, equal to the expected value for each parameter. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.671048 [article] Influence of the spatial variability of leaching kinetics parameters on the lifespan of a concrete structure [texte imprimé] / Thomas de Larrard, Auteur ; Benboudjema, Farid, Auteur ; Jean-Baptiste Colliat, Auteur . - 2012 . - pp. 606-624. Génie Civil Langues : Anglais (eng) in European journal of environmental and civil engineering > Vol. 16 N° 5 (Mai 2012) . - pp. 606-624 Mots-clés : Leaching  Porosity  Tortuosity  Variability  Distribution  Correlation  length  Karhunen--Loève  expansion  Monte  Carlo  method Résumé : This works aims at studying, through the Monte Carlo method, the influence of the leaching kinetics parameters spatial variability on the lifespan of a concrete structure. The considered structure is a tunnel for nuclear waste storage. It is observed that the expected value for the lifespan estimated when considering the material spatial variability is significantly lower than the lifespan estimated with a single simulation considering uniform parameter fields, equal to the expected value for each parameter. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.671048

Sulphatic attack in concrete structures in cold mountainous zones / A. Pavoine in European journal of environmental and civil engineering, Vol. 16 N° 5 (Mai 2012) 

Public ISBD [article]  in European journal of environmental and civil engineering > Vol. 16 N° 5 (Mai 2012) . - pp. 625-634 Titre : Sulphatic attack in concrete structures in cold mountainous zones Type de document : texte imprimé Auteurs : A. Pavoine, Auteur ; L. Divet, Auteur ; E. Premat, Auteur Année de publication : 2012 Article en page(s) : pp. 625-634 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Concrete  Pathology  Sulphates  Expansion  Ettringite  Thaumasite Résumé : In 2006, experiments were conducted on 90 concrete ski lift foundation elements. The concrete was contaminated with sulphates whose content by mass varied between 0.9% and 14%. The concrete was manufactured with type CEM I cement, limestone (calcium carbonate and dolomite) and siliceous aggregates with highly variable proportions of anhydrite. There was a considerable danger that the thaumasite form of sulphate attack would occur in these concretes because of their exposure to low temperatures (T <15°C). Tests were conducted on core samples taken from the structures to provoke the formation of thaumasite (immersion at 5°C) or ettringite (immersion at 20°C). After 900 days of monitoring, some concretes exhibited particularly severe deterioration. Conservation at low temperature led to severe swelling, failure and a marked loss of cohesion in some concretes with a high sulphate content (SO3 > 7% by weight). Development of the disorder is not only related to the total sulphate content. Factors that could not be characterised, such as the distribution and size of the anhydrite particles must also be taken into account. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.668019 [article] Sulphatic attack in concrete structures in cold mountainous zones [texte imprimé] / A. Pavoine, Auteur ; L. Divet, Auteur ; E. Premat, Auteur . - 2012 . - pp. 625-634. Génie Civil Langues : Anglais (eng) in European journal of environmental and civil engineering > Vol. 16 N° 5 (Mai 2012) . - pp. 625-634 Mots-clés : Concrete  Pathology  Sulphates  Expansion  Ettringite  Thaumasite Résumé : In 2006, experiments were conducted on 90 concrete ski lift foundation elements. The concrete was contaminated with sulphates whose content by mass varied between 0.9% and 14%. The concrete was manufactured with type CEM I cement, limestone (calcium carbonate and dolomite) and siliceous aggregates with highly variable proportions of anhydrite. There was a considerable danger that the thaumasite form of sulphate attack would occur in these concretes because of their exposure to low temperatures (T <15°C). Tests were conducted on core samples taken from the structures to provoke the formation of thaumasite (immersion at 5°C) or ettringite (immersion at 20°C). After 900 days of monitoring, some concretes exhibited particularly severe deterioration. Conservation at low temperature led to severe swelling, failure and a marked loss of cohesion in some concretes with a high sulphate content (SO3 > 7% by weight). Development of the disorder is not only related to the total sulphate content. Factors that could not be characterised, such as the distribution and size of the anhydrite particles must also be taken into account. DEWEY : 624 ISSN : 1964-8189 En ligne : http://www.tandfonline.com/doi/abs/10.1080/19648189.2012.668019

Exemplaires

Bibliothèque Ecole Nationale Polytechnique d'Alger

Accueil

Se connecter

Météo

Adresse