Le verbe tremper vient du latin « temperare » qui contient la notion de tempérer, modérer, très éloignée de l’action, plutôt violente, de plonger dans l’eau une pièce d’acier porté au rouge, ce qui est aujourd’hui la définition de « tremper l’acier ». Par contre, dans les siècles passés, « tremper l’acier » a eu différentes significations, allant jusqu’au processus complet de chauffage, durcissement à l’eau et revenu, avec de nombreuses variantes. L’objectif était d’obtenir un état optimisé entre la dureté et la fragilité, ce que contenait le verbe « temperare ». Ce premier article présente les différents traitements appelés « trempe », puis les anciens moyens de contrôler les températures, les bains de trempe aux compositions parfois magiques et les défauts induits par la trempe. Le dernier paragraphe déroule l’historique du vocabulaire de ces traitements depuis Homère, jusqu’à l’apparition de « temperare » dans les écrits du 12e siècle et à la normalisation du langage à la fin du 19e siècle. Un deuxième article analysera la lente évolution, depuis le Moyen Âge, des descriptions des mécanismes de la trempe, largement fondées sur les conceptions de la matière par Aristote, jusqu’à l’apparition des nouveaux concepts cristallographiques et atomiques de la constitution des métaux, au début du 20e siècle, exposés dans un troisième article.
{"title":"La trempe des aciers, points de vue techniques, historiques et scientifiques. Vingt-cinq siècles d’évolution de la trempe des aciers","authors":"Jean Le Coze","doi":"10.1051/mattech/2021026","DOIUrl":"https://doi.org/10.1051/mattech/2021026","url":null,"abstract":"Le verbe tremper vient du latin « temperare » qui contient la notion de tempérer, modérer, très éloignée de l’action, plutôt violente, de plonger dans l’eau une pièce d’acier porté au rouge, ce qui est aujourd’hui la définition de « tremper l’acier ». Par contre, dans les siècles passés, « tremper l’acier » a eu différentes significations, allant jusqu’au processus complet de chauffage, durcissement à l’eau et revenu, avec de nombreuses variantes. L’objectif était d’obtenir un état optimisé entre la dureté et la fragilité, ce que contenait le verbe « temperare ». Ce premier article présente les différents traitements appelés « trempe », puis les anciens moyens de contrôler les températures, les bains de trempe aux compositions parfois magiques et les défauts induits par la trempe. Le dernier paragraphe déroule l’historique du vocabulaire de ces traitements depuis Homère, jusqu’à l’apparition de « temperare » dans les écrits du 12e siècle et à la normalisation du langage à la fin du 19e siècle. Un deuxième article analysera la lente évolution, depuis le Moyen Âge, des descriptions des mécanismes de la trempe, largement fondées sur les conceptions de la matière par Aristote, jusqu’à l’apparition des nouveaux concepts cristallographiques et atomiques de la constitution des métaux, au début du 20e siècle, exposés dans un troisième article.","PeriodicalId":43816,"journal":{"name":"Materiaux & Techniques","volume":"482 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57960572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The use of hydrogen as fuel in the reheating furnaces, to replace (partially or totally) natural gas, causes a modification in the composition of the furnace atmosphere, with low or null concentration of CO2 and an increased concentration of H2O. The new atmosphere may change the scale growth kinetic and may affect the surface properties, in terms of scale removal and formation of decarburized layer. These effects can be studied at laboratory scale simulating the atmosphere generated by H2 combustion considering the working conditions of the burner and the excess oxygen. Hence, the comprehension and quantification of this effect is a fundamental pre-requisite for the use of hydrogen as fuel in reheating and treatment furnaces. For this reason, TenarisDalmine and Rina CSM carried out an experimental activity to simulate reheating and heat treatment process selecting two steels grades: one for line pipe production and one for casing production, two steels in which the more remarkable differences for scale growth and adherence are in the C and Ni content [1,2]. The experimental scenario was defined to verify the effects of the combustion atmosphere simulating the heating of a 20 mm thick pipe at 920 °C and the reheating process at 1230 °C for 180 min. The trials included two possible combustion atmospheres having different H2O concentration and corresponding to 100% natural gas and 100% H2. The steel oxidation and scale formation were studied by TGA (Thermo Gravimetric Analysis) tests. Results showed some increase in scale growth up to 10% during heating at 920 °C and up to 16% in case of re-heating at 1230 °C. The differences between line pipe and casing steel grades were minimal with a slight tendency to higher oxidation for line pipe steel. No decarburization was observed in steel sample heated at 920 °C oxidized in both atmospheres (with 100% natural gas or 100% H2 combustion). Metallographic analysis on TGA samples confirms, for the test with atmosphere form 100%H2, at 1230 °C, the increased thickness of the scale; in these tests, the interface between scale and steel appears more complex and entangled.
{"title":"Effects of H2 combustion on scale growth and steel surface quality in reheating furnaces","authors":"F. Cirilli, G. Jochler, M. Mosconi, F. Praolini","doi":"10.1051/mattech/2021024","DOIUrl":"https://doi.org/10.1051/mattech/2021024","url":null,"abstract":"The use of hydrogen as fuel in the reheating furnaces, to replace (partially or totally) natural gas, causes a modification in the composition of the furnace atmosphere, with low or null concentration of CO2 and an increased concentration of H2O. The new atmosphere may change the scale growth kinetic and may affect the surface properties, in terms of scale removal and formation of decarburized layer. These effects can be studied at laboratory scale simulating the atmosphere generated by H2 combustion considering the working conditions of the burner and the excess oxygen. Hence, the comprehension and quantification of this effect is a fundamental pre-requisite for the use of hydrogen as fuel in reheating and treatment furnaces. For this reason, TenarisDalmine and Rina CSM carried out an experimental activity to simulate reheating and heat treatment process selecting two steels grades: one for line pipe production and one for casing production, two steels in which the more remarkable differences for scale growth and adherence are in the C and Ni content [1,2]. The experimental scenario was defined to verify the effects of the combustion atmosphere simulating the heating of a 20 mm thick pipe at 920 °C and the reheating process at 1230 °C for 180 min. The trials included two possible combustion atmospheres having different H2O concentration and corresponding to 100% natural gas and 100% H2. The steel oxidation and scale formation were studied by TGA (Thermo Gravimetric Analysis) tests. Results showed some increase in scale growth up to 10% during heating at 920 °C and up to 16% in case of re-heating at 1230 °C. The differences between line pipe and casing steel grades were minimal with a slight tendency to higher oxidation for line pipe steel. No decarburization was observed in steel sample heated at 920 °C oxidized in both atmospheres (with 100% natural gas or 100% H2 combustion). Metallographic analysis on TGA samples confirms, for the test with atmosphere form 100%H2, at 1230 °C, the increased thickness of the scale; in these tests, the interface between scale and steel appears more complex and entangled.","PeriodicalId":43816,"journal":{"name":"Materiaux & Techniques","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57960524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pour réduire le problème d’incompatibilité entre le bois et le ciment, un traitement du renfort bois, par de l’eau bouillante peut être une solution afin d’éliminer les composés qui inhibent la prise du ciment. L’effet de la teneur de poudre de bois d’Eucalyptus camaldulensis Dehn naturel et traité thermiquement à l’eau bouillante sur la cinétique d’hydratation a été étudié par calorimétrie isotherme, conductimétrie et thermogravimétrie (ATG). La poudre de bois diminue légèrement la consommation du gypse et retarde l’hydratation des phases silicates. À des concentrations massiques élevées de 25 % et 30 %, le bois retarde fortement la précipitation de la portlandite. À des teneurs de 10 % en masse de poudre de bois, le traitement n’a pas montré d’efficacité sur la cinétique d’hydratation ; à 20 % de bois traité, l’hydratation du ciment est accélérée par rapport au témoin. Les extractibles du bois n’ont pas affecté la formation de l’ettringite due à la présence d’ions de sulfate de bois.
{"title":"Étude de l’influence de l’incorporation de la poudre de bois d’Eucalyptus camaldulensis Dehn algérien sur la cinétique d’hydratation du coulis de ciment","authors":"Linda Anes, Mansour Tazrout, Alexandre Govin","doi":"10.1051/mattech/2021021","DOIUrl":"https://doi.org/10.1051/mattech/2021021","url":null,"abstract":"Pour réduire le problème d’incompatibilité entre le bois et le ciment, un traitement du renfort bois, par de l’eau bouillante peut être une solution afin d’éliminer les composés qui inhibent la prise du ciment. L’effet de la teneur de poudre de bois d’Eucalyptus camaldulensis Dehn naturel et traité thermiquement à l’eau bouillante sur la cinétique d’hydratation a été étudié par calorimétrie isotherme, conductimétrie et thermogravimétrie (ATG). La poudre de bois diminue légèrement la consommation du gypse et retarde l’hydratation des phases silicates. À des concentrations massiques élevées de 25 % et 30 %, le bois retarde fortement la précipitation de la portlandite. À des teneurs de 10 % en masse de poudre de bois, le traitement n’a pas montré d’efficacité sur la cinétique d’hydratation ; à 20 % de bois traité, l’hydratation du ciment est accélérée par rapport au témoin. Les extractibles du bois n’ont pas affecté la formation de l’ettringite due à la présence d’ions de sulfate de bois.","PeriodicalId":43816,"journal":{"name":"Materiaux & Techniques","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57960456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Irene Luzzo, F. Cirilli, G. Jochler, Alessio Gambato, Jacopo Longhi, Gabriele Rampinini
In the deep steel industry decarbonization, green hydrogen plays a pivotal role as alternative energy to replace natural gas and carbon bearing materials. In this frame, technical aspects and in general criticalities relevant to the use of mixtures of hydrogen and natural gas in industrial processes were investigated: in particular its effect was analyzed on employ of existing industrial burners for treatment furnace and on oxidability and descaling susceptibility of forged material as Grade F22V and Inconel® 625. The experimental campaign on burner using blends with 30% and 50%vol. of hydrogen in natural gas highlighted that it is possible to ignite the burner for both mixtures, but that the burner is more stable with the 30%vol. of hydrogen in natural gas. The detected emissions of nitrogen oxides compared to the natural gas increase up to 15%. The results indicated that selected high speed burner should be used in industrial plant with a 30% of hydrogen in volume with no need of hardware modifications. The oxidation investigation on atmospheres deriving from the combustion of 100% of hydrogen, at 1230 °C, showed a moderate scale increase up to 14% for F22V grade and 8% for Inconel® 625. This increase of scale growth has not detrimental effect on the scale removability. For the selected reference industrial scenario, the burner was positively tested in industrial furnace with a 30% of hydrogen in volume with no need of hardware modifications. Moderate scale growth was observed, but with no detrimental effect on the scale removability. Moreover, the H2 addition allows to get CO2 reductions, without any noticeable drawback on other process parameters or product quality for this industrial scenario.
{"title":"Feasibility study for the utilization of natural gas and hydrogen blends on industrial furnaces","authors":"Irene Luzzo, F. Cirilli, G. Jochler, Alessio Gambato, Jacopo Longhi, Gabriele Rampinini","doi":"10.1051/mattech/2022006","DOIUrl":"https://doi.org/10.1051/mattech/2022006","url":null,"abstract":"In the deep steel industry decarbonization, green hydrogen plays a pivotal role as alternative energy to replace natural gas and carbon bearing materials. In this frame, technical aspects and in general criticalities relevant to the use of mixtures of hydrogen and natural gas in industrial processes were investigated: in particular its effect was analyzed on employ of existing industrial burners for treatment furnace and on oxidability and descaling susceptibility of forged material as Grade F22V and Inconel® 625. The experimental campaign on burner using blends with 30% and 50%vol. of hydrogen in natural gas highlighted that it is possible to ignite the burner for both mixtures, but that the burner is more stable with the 30%vol. of hydrogen in natural gas. The detected emissions of nitrogen oxides compared to the natural gas increase up to 15%. The results indicated that selected high speed burner should be used in industrial plant with a 30% of hydrogen in volume with no need of hardware modifications. The oxidation investigation on atmospheres deriving from the combustion of 100% of hydrogen, at 1230 °C, showed a moderate scale increase up to 14% for F22V grade and 8% for Inconel® 625. This increase of scale growth has not detrimental effect on the scale removability. For the selected reference industrial scenario, the burner was positively tested in industrial furnace with a 30% of hydrogen in volume with no need of hardware modifications. Moderate scale growth was observed, but with no detrimental effect on the scale removability. Moreover, the H2 addition allows to get CO2 reductions, without any noticeable drawback on other process parameters or product quality for this industrial scenario.","PeriodicalId":43816,"journal":{"name":"Materiaux & Techniques","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57960201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To estimate the risk of brittle fracture of a component in service, Charpy tests are generally carried out on 3 samples at the same temperature. Work done over many years on welded joint fatigue using probability and statistics has shown that to have a good assessment of minimum strength, it is clearly necessary to have a larger number of test results. In order to analyse the risks associated with this practice of 3 samples tested at the same temperature, a series of 17 Charpy impact test results of samples of the same steel plate was chosen. From this series, by translation, 2 series were generated, one with a test of 3 specimens showing acceptable steel and one with a test of 3 specimens showing unacceptable steel. The 3-test method was applied to these series leading to a possible simulation of 12 tests each. It was found that the 3-test practice leads to a risk of error of 30 to 40%. It is also found that the determination of the transition curve of a DH36 steel finally shows that its temperature for a CV of 27 J is of the order of −50 °C whereas the regulations require only −20 °C. In conclusion, a possible improvement of the test procedure is indicated, which is the subject of a study within the framework of the “CCRS rupture and fatigue” working groups of the Société des Ingénieurs Soudeurs (SIS).
{"title":"Charpy V notch tests – Risks associated with testing with 3 samples","authors":"M. Huther, H. Lieurade","doi":"10.1051/mattech/2021017","DOIUrl":"https://doi.org/10.1051/mattech/2021017","url":null,"abstract":"To estimate the risk of brittle fracture of a component in service, Charpy tests are generally carried out on 3 samples at the same temperature. Work done over many years on welded joint fatigue using probability and statistics has shown that to have a good assessment of minimum strength, it is clearly necessary to have a larger number of test results. In order to analyse the risks associated with this practice of 3 samples tested at the same temperature, a series of 17 Charpy impact test results of samples of the same steel plate was chosen. From this series, by translation, 2 series were generated, one with a test of 3 specimens showing acceptable steel and one with a test of 3 specimens showing unacceptable steel. The 3-test method was applied to these series leading to a possible simulation of 12 tests each. It was found that the 3-test practice leads to a risk of error of 30 to 40%. It is also found that the determination of the transition curve of a DH36 steel finally shows that its temperature for a CV of 27 J is of the order of −50 °C whereas the regulations require only −20 °C. In conclusion, a possible improvement of the test procedure is indicated, which is the subject of a study within the framework of the “CCRS rupture and fatigue” working groups of the Société des Ingénieurs Soudeurs (SIS).","PeriodicalId":43816,"journal":{"name":"Materiaux & Techniques","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57959830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Phosphogypsum (PG) is an acidic by-product generated during the production of phosphoric acid. Usually this by-product is stockpiled or dumped into water bodies, which causes several environmental pollution problems. The aim of this work is to reduce this environmental risk by producing CaCO3 and Li2SO4.H2O from the conversion of PG by Li2CO3. To optimize the reaction conditions, four parameters have been investigated such as the initial concentration of the reagents, the reaction duration, the temperature and the gypsum purity. In addition, the nature of the resulting products was proved principally by X-ray diffraction technic. The obtained results show that the initial concentration of the reagents and the reaction duration are the most influential parameters, while the temperature has no significance effect on this reaction. Also, the acidity and the presence of impurities into PG induce its reactivity compared than commercial gypsum. The purity of the formed CaCO3 and Li2SO4.H2O at the optimum conversion of PG is 96.08 and 98.71% respectively.
{"title":"Optimization of phosphogypsum conversion into calcium carbonate and lithium sulfate monohydrate","authors":"Y. Ennaciri, M. Bettach","doi":"10.1051/mattech/2021020","DOIUrl":"https://doi.org/10.1051/mattech/2021020","url":null,"abstract":"Phosphogypsum (PG) is an acidic by-product generated during the production of phosphoric acid. Usually this by-product is stockpiled or dumped into water bodies, which causes several environmental pollution problems. The aim of this work is to reduce this environmental risk by producing CaCO3 and Li2SO4.H2O from the conversion of PG by Li2CO3. To optimize the reaction conditions, four parameters have been investigated such as the initial concentration of the reagents, the reaction duration, the temperature and the gypsum purity. In addition, the nature of the resulting products was proved principally by X-ray diffraction technic. The obtained results show that the initial concentration of the reagents and the reaction duration are the most influential parameters, while the temperature has no significance effect on this reaction. Also, the acidity and the presence of impurities into PG induce its reactivity compared than commercial gypsum. The purity of the formed CaCO3 and Li2SO4.H2O at the optimum conversion of PG is 96.08 and 98.71% respectively.","PeriodicalId":43816,"journal":{"name":"Materiaux & Techniques","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57960416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Corrosion of steel constitutes a major preoccupation in the field of civil engineering and the building sector. In this paper, we investigated the electrochemical behavior of two steel specimens with different forms (latched steel and smooth steel) in a 3 wt.% NaCl solution. For this purpose, we studied the steel samples by linear polarization, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The surface morphologies of the substrates were examined by scanning electron microscopy coupled with energy diffraction spectroscopy (SEM/EDS). Results of linear polarization, Tafel polarization curves and EIS show that latched steel (LS) is more susceptible to corrosion than smooth steel (SS) in saline solution. Gravimetric and SEM/EDS analysis after 10 days of immersion confirmed the results obtained by electrochemical methods. All of our results are in agreement and demonstrate that the sample form plays a key role in corrosion resistance.
{"title":"Effect of the sample form on the corrosion behavior of steels for concrete in 3% NaCl medium","authors":"Laidi Babouri, Cheikh Mokrani, Y. El Mendili","doi":"10.1051/mattech/2021018","DOIUrl":"https://doi.org/10.1051/mattech/2021018","url":null,"abstract":"Corrosion of steel constitutes a major preoccupation in the field of civil engineering and the building sector. In this paper, we investigated the electrochemical behavior of two steel specimens with different forms (latched steel and smooth steel) in a 3 wt.% NaCl solution. For this purpose, we studied the steel samples by linear polarization, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The surface morphologies of the substrates were examined by scanning electron microscopy coupled with energy diffraction spectroscopy (SEM/EDS). Results of linear polarization, Tafel polarization curves and EIS show that latched steel (LS) is more susceptible to corrosion than smooth steel (SS) in saline solution. Gravimetric and SEM/EDS analysis after 10 days of immersion confirmed the results obtained by electrochemical methods. All of our results are in agreement and demonstrate that the sample form plays a key role in corrosion resistance.","PeriodicalId":43816,"journal":{"name":"Materiaux & Techniques","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57959876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mahmoud Hayek, M. Salgues, F. Habouzit, S. Bayle, Jean-Claude Souche, Klartjee De Weerdt, Sylvain Pioch
Les ingénieurs spécialisés en génie civil doivent intégrer dans leur design des mesures de protection de la biodiversité marine de qui autorise le concept d’écoconception d’infrastructures marines respectueuses de l’environnement. Les matériaux cimentaires sont privilégiés pour concevoir les infrastructures marines et interagissent avec le milieu marin. Ces structures seront colonisées par des micro-organismes et macroorganismes marins. Dans un premier temps, les organismes forment un biofilm à la surface du béton en fonction des facteurs environnementaux et des propriétés physico-chimiques du matériau. Dans cette étude, il a été démontré que la pré-carbonatation des matériaux cimentaires accélère la croissance des micro-organismes formant le biofilm à leur surface en abaissant le pH de la surface. Il a été démontré en laboratoire que la colonisation de la surface par des micro-organismes augmente également l’hydrophobicité de la surface et pourrait ainsi améliorer la durabilité du matériau en diminuant l’absorption d’eau de mer contenant des agents agressifs.
{"title":"L’influence de la carbonatation sur la biocolonisation de matériaux cimentaires dans le milieu marin","authors":"Mahmoud Hayek, M. Salgues, F. Habouzit, S. Bayle, Jean-Claude Souche, Klartjee De Weerdt, Sylvain Pioch","doi":"10.1051/mattech/2020020","DOIUrl":"https://doi.org/10.1051/mattech/2020020","url":null,"abstract":"Les ingénieurs spécialisés en génie civil doivent intégrer dans leur design des mesures de protection de la biodiversité marine de qui autorise le concept d’écoconception d’infrastructures marines respectueuses de l’environnement. Les matériaux cimentaires sont privilégiés pour concevoir les infrastructures marines et interagissent avec le milieu marin. Ces structures seront colonisées par des micro-organismes et macroorganismes marins. Dans un premier temps, les organismes forment un biofilm à la surface du béton en fonction des facteurs environnementaux et des propriétés physico-chimiques du matériau. Dans cette étude, il a été démontré que la pré-carbonatation des matériaux cimentaires accélère la croissance des micro-organismes formant le biofilm à leur surface en abaissant le pH de la surface. Il a été démontré en laboratoire que la colonisation de la surface par des micro-organismes augmente également l’hydrophobicité de la surface et pourrait ainsi améliorer la durabilité du matériau en diminuant l’absorption d’eau de mer contenant des agents agressifs.","PeriodicalId":43816,"journal":{"name":"Materiaux & Techniques","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2020-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48049006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This research aims at understanding better the nature of stakeholders’ resistance to and interest in repair and reuse. In fact, the authors assume that in the future waste management could be less centralized using a network of territorialized initiatives based on repair and reuse activities with high social and environmental values. Such system innovation requires tools and methods to support analysis and facilitate decision-making in multi-stakeholders, multi-scales systems. The framework for spatiotemporal analysis of territorial projects considers a project’s stakeholder network and the way they mobilize resources. These resources may be tangible or intangible, brought by individuals, organizations or even the territory. This communication focuses on the implementation of such an analysis in the community of communes Coeur de Savoie, to understand how local initiatives emerge and on which interactions and resources they are based. This paper proposes feedback on the implementation of the spatio-temporal analysis in one case study (Coeur de Savoie), and provides insights to build new networks promoting reuse and repair.
本研究旨在更好地理解利益相关者对修复和重用的抵制和兴趣的本质。事实上，作者认为，在未来，废物管理可以通过基于具有高社会和环境价值的修复和再利用活动的地域性倡议网络来减少集中化。这种系统创新需要工具和方法来支持多利益相关者、多尺度系统中的分析和促进决策。地域项目的时空分析框架考虑了项目的利益相关者网络及其调动资源的方式。这些资源可能是有形的，也可能是无形的，由个人、组织甚至领土带来。本来文的重点是在萨瓦之心社区实施这种分析，以了解地方倡议是如何产生的，以及这些倡议是基于哪些相互作用和资源。本文以一个案例(Coeur de Savoie)为例，对时空分析的实施提出了反馈意见，并为构建促进重用和修复的新网络提供了见解。
{"title":"(Im-)material flow analysis framework implementation on repair and reuse initiatives","authors":"J. Gobert, Romain Allais","doi":"10.1051/mattech/2021012","DOIUrl":"https://doi.org/10.1051/mattech/2021012","url":null,"abstract":"This research aims at understanding better the nature of stakeholders’ resistance to and interest in repair and reuse. In fact, the authors assume that in the future waste management could be less centralized using a network of territorialized initiatives based on repair and reuse activities with high social and environmental values. Such system innovation requires tools and methods to support analysis and facilitate decision-making in multi-stakeholders, multi-scales systems. The framework for spatiotemporal analysis of territorial projects considers a project’s stakeholder network and the way they mobilize resources. These resources may be tangible or intangible, brought by individuals, organizations or even the territory. This communication focuses on the implementation of such an analysis in the community of communes Coeur de Savoie, to understand how local initiatives emerge and on which interactions and resources they are based. This paper proposes feedback on the implementation of the spatio-temporal analysis in one case study (Coeur de Savoie), and provides insights to build new networks promoting reuse and repair.","PeriodicalId":43816,"journal":{"name":"Materiaux & Techniques","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57959821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
While resource aspects are gaining increasing importance for the sustainability assessment of new technologies, the question of how to assess the depletion of abiotic resources is still controversially discussed. Different methodologies exist for their quantification within life cycle assessment (LCA). Among them, thermodynamic approaches have the advantage of considering aspects of absolute quantity (reserves or amount of a substance contained in total in earth’s crust) and of quality (concentration of the target element in the mined resource), making them a potentially appealing approach for assessing resource depletion. However, existing approaches are either far from the original thermodynamic idea of exergy or far too complex and not applicable for resource accounting. This work briefly discusses the suitability of exergy-based approaches for resource assessment, and then suggests a simple but comprehensive methodology for quantifying resource depletion related with the concept of chemical concentration exergy (MDPces). It provides a calculation approach for quantifying the MDPces and estimates the corresponding values for some representative key metals.
{"title":"Reinventing exergy as indicator for resource depletion impacts in LCA","authors":"J. Peters","doi":"10.1051/mattech/2021003","DOIUrl":"https://doi.org/10.1051/mattech/2021003","url":null,"abstract":"While resource aspects are gaining increasing importance for the sustainability assessment of new technologies, the question of how to assess the depletion of abiotic resources is still controversially discussed. Different methodologies exist for their quantification within life cycle assessment (LCA). Among them, thermodynamic approaches have the advantage of considering aspects of absolute quantity (reserves or amount of a substance contained in total in earth’s crust) and of quality (concentration of the target element in the mined resource), making them a potentially appealing approach for assessing resource depletion. However, existing approaches are either far from the original thermodynamic idea of exergy or far too complex and not applicable for resource accounting. This work briefly discusses the suitability of exergy-based approaches for resource assessment, and then suggests a simple but comprehensive methodology for quantifying resource depletion related with the concept of chemical concentration exergy (MDPces). It provides a calculation approach for quantifying the MDPces and estimates the corresponding values for some representative key metals.","PeriodicalId":43816,"journal":{"name":"Materiaux & Techniques","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57960032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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