Environmental life cycle assessment of industrialization process of calcined dredged sediments

This research focus on the life cycle assessment (LCA) of dredged sediments valorization. This tool is part of an environmental management approach, which makes it possible to compare the environmental loads of the different stages of the life cycle of the same product and, by the way to deduce the most polluting step in environmental terms and thus the industrialization process of dredging sediments of dams is optimized by modelling using the GEMIS (Global Emission Model for Integrated Systems) 4.95 software and the classification and characterization method. To propose a model that is the more respectful of the environment, by determining the most environmentally friendly scenario, in order to exploit these dredged sediments after calcination treatment to make them active in the field of the building’s construction. The results of this life cycle analysis study of the new industrialization process of dredged sediments show that climate change potential (GHG) is 0,246 ton of CO2eq/t of sediments, acidification potential is 4,55×10-4 ton of SO2 eq/t of sediments, the tropospheric ozone precursor potential is 9,97×10-4 ton of TOPP eq/t of sediments and the cumulative energy and exergy demand is 2506,75 in MJ/t of sediments, these values are compared to others carried out in Algeria

Environmental life cycle assessment of industrialization process of calcined dredged sediments

This research focus on the life cycle assessment (LCA) of dredged sediments valorization. This tool is part of an environmental management approach, which makes it possible to compare the environmental loads of the different stages of the life cycle of the same product and, by the way to deduce the most polluting step in environmental terms and thus the industrialization process of dredging sediments of dams is optimized by modelling using the GEMIS (Global Emission Model for Integrated Systems) 4.95 software and the classification and characterization method. To propose a model that is the more respectful of the environment, by determining the most environmentally friendly scenario, in order to exploit these dredged sediments after calcination treatment to make them active in the field of the building’s construction. The results of this life cycle analysis study of the new industrialization process of dredged sediments show that climate change potential (GHG) is 0,246 ton of CO2eq/t of sediments, acidification potential is 4,55×10-4 ton of SO2 eq/t of sediments, the tropospheric ozone precursor potential is 9,97×10-4 ton of TOPP eq/t of sediments and the cumulative energy and exergy demand is 2506,75 in MJ/t of sediments, these values are compared to others carried out in Algeria

Environmental life cycle assessment of industrialization process of calcined dredged sediments

This research focus on the life cycle assessment (LCA) of dredged sediments valorization. This tool is part of an environmental management approach, which makes it possible to compare the environmental loads of the different stages of the life cycle of the same product and, by the way to deduce the most polluting step in environmental terms and thus the industrialization process of dredging sediments of dams is optimized by modelling using the GEMIS (Global Emission Model for Integrated Systems) 4.95 software and the classification and characterization method. To propose a model that is the more respectful of the environment, by determining the most environmentally friendly scenario, in order to exploit these dredged sediments after calcination treatment to make them active in the field of the building’s construction. The results of this life cycle analysis study of the new industrialization process of dredged sediments show that climate change potential (GHG) is 0,246 ton of CO2eq/t of sediments, acidification potential is 4,55×10-4 ton of SO2 eq/t of sediments, the tropospheric ozone precursor potential is 9,97×10-4 ton of TOPP eq/t of sediments and the cumulative energy and exergy demand is 2506,75 in MJ/t of sediments, these values are compared to others carried out in Algeria

Hydro/Hygrothermal Behavior of Plant Fibers and Its Influence on Bio-Composite Properties

Plant fibers have been shown to be highly sensitive to water molecules; this impacts the functionality of composites reinforced with these fibers, commonly known as bio-composites. This review aims to provide a comprehensive description of the behavior of plant fibers in the presence of water molecules in a liquid or gaseous state, as well as the different phenomena and mechanisms involved at the fiber scale and at the bio-composite scale via recent studies in this field. First, we will discuss the physical problem of sorption in polymers in a general way, and then we will focus on the case of plant fibers. Particular attention will be given to the adsorption kinetics of plant fibers and the models used to determine their diffusion parameters. In a second step, the effect of the incorporation of plant fibers in polymer matrices will be examined as well as the different factors influencing the diffusive behavior of bio-composites. In addition, the effect of hydro/hygrothermal aging on the mechanical properties of bio-composites will be discussed

Etude de la pénétration des chlorures et de l'amorçage de la corrosion en zone saturée et en zone de marnage

La corrosion des armatures est une des causes principales de la dégradation des structures en béton armé en Europe. Plus particulièrement en zones côtières, où les ions chlore, présents dans l eau de mer, ont clairement été identifiés comme étant l'élément déclencheur du processus chimique menant à la corrosion. Dans ce contexte, la détermination de cette valeur critique d amorçage de la corrosion et le temps correspondant sont des éléments clés de la prédiction de la duré de vie des matériaux. Dans ce travail, quatre types de bétons armés ordinaires (C15, C22, C4 et C30) ont été placés dans trois environnements différents : une zone de marnage au port de La Rochelle, un simulateur de marnage avec une solution saline (0,5M NaCl) conçu au laboratoire où les conditions d exposition sont contrôlées et une cellule de migration où un champ électrique a été appliqué afin d accélérer la pénétration des chlorures. Des mesures électrochimiques (spectroscopie d impédance électrochimique SIE, potentiel de corrosion et résistance de polarisation) ont été réalisées afin de suivre le processus de transport aboutissant à la corrosion. Une étude de caractérisation des matériaux a été réalisée dans le but de relever les propriétés de transfert de chaque béton. La description morphologique (MEB Microscopie Electronique et EDXA Energy Dispersive X-ray Analysis) de l interface acier-béton a apporté des compléments sur la microstructure et les mécanismes physico-chimiques mis en jeu. Enfin, un modèle numérique unidimensionnel et multi-espèces de transport des chlorures, basé sur l équation de Nernst-Planck, a été développé. La réactivité chimique du matériau cimentaire est prise en compte à travers les isothermes d interaction.The reinforcement corrosion is one of the main causes of degradation of reinforced concrete structures in Europe. More particularly in coastal areas where chloride ions, present in sea water, were clearly identified as the trigger factor of chemical process leading to corrosion. At this time, corrosion initiates. In this context, the determination of this critical value for the corrosion initiation and the corresponding time are the key elements in the prediction of the prediction of materials service life. In this work, four types of ordinary reinforced concretes (C15, C22, C4 and C30) have been exposed in three different environments: A tidal area at the port of La Rochelle, a tidal simulator with a saline solution (0,5 M NaCl) designed in the laboratory where the exposure conditions are controlled and a cell migration where an electric field has been applied in order to speed up the chlorides penetration. Electrochemical measurements (electrochemical impedance spectroscopy EIS, corrosion potential and polarization resistance) were carried out to follow the transport processes leading to the corrosion. A study of materials characterization was performed to collect transfer properties of each concrete. Morphological descriptions (SEM Scanning Electron Microscopy and EDXA Energy Dispersive X-ray Analysis) of the steel-concrete interface gave further informations on the microstructure and the physico-chemical mechanisms. Finally, a one-dimensional numerical model and multi-species of chloride transport based on the Nernst-Planck equation was developed. The Chemical reactivity of cement based materials is taken into account through the adsorption isotherms.LA ROCHELLE-BU (173002101) / SudocSudocFranceF

Effect of Chemical and Physical Treatments on Mechanical Properties of Diss Fibers-Based Biocomposites Materials

This work highlights the exploitation of fibers from a promising plant, commonly called Diss, in polymer matrix reinforcement. In this context, various untreated and treated (with acetic acid, silane, NaOH, thermal) Diss fibers were used to reinforce a thermoplastic matrix, polypropylene (PP). The effect of fiber treatments was evaluated at a ratio of 10% (by mass) of fiber, using mechanical, microstructural and physical characterization. A fiber content optimization study was carried out after choosing the fiber treatment by varying the fiber content from 10% to 40%. The microstructure observations showed a multi-layer structure for the biocomposites studied. The particular morphology of Diss fibers, with the presence of thorns, seems to improve the mechanical adhesion between the two phases. For 10% fiber content composites, the incorporation of the different fibers in the PP matrix led to improvements in most mechanical properties. The biocomposite reinforced with NaOH treated fibers (NPP-10%) showed the best mechanical performance with an improvement of 30%, 22% and 9% in tensile modulus, bending modulus and bending stress, respectively. For the fiber content variation, the NPP was retained, and an enhancement in the tensile modulus was found when the fiber content was below 20%

Development of a numerical approach to assess the effect of coupled heat and moisture transfer on energy consumption of residential buildings in Moroccan context

International audienceHygrothermal properties of building materials, climatic conditions and energy performance are interrelated and have to be considered simultaneously as part of an optimised building design. In this paper, a new approach to evaluate the energy consumption of residential buildings in Morocco is presented. This approach is based on the effect of coupled heat and moisture transfer in typical residential buildings and on their responses to the varied climatic conditions encountered in the country. This approach allows us to evaluate with better accuracy the response of building energy performance and the indoor comfort of building occupants. Annual energy consumption, cooling and heating energy requirements were estimated considering the six climatic zones of Morocco. Based on the results, terms related to coupled heat and moisture transfer can effectively correct the existing energy consumption calculations of the six zones of Morocco, which currently do not consider energy consumption due to coupled heat and moisture transfer

Influence of the origin of metakaolin on pozzolanic reactivity of mortars

International audienc

Influence of the pozzolanic reactivity of the Blast Furnace Slag (BFS) and metakaolin on mortars

International audienc

Plant Extraction and Physicochemical Characterizations of Untreated and Pretreated Diss Fibers (Ampelodesmos mauritanicus)

The Ampelodesmos mauritanicus plant, Mauritanian grass or also called ‘Diss’, is a perennial abundant plant on the Mediterranean contour, having attractive characteristics for ecofriendly materials. This work aims to highlight the potential of the Diss fibers elements by assessing their use as reinforcement for polymer matrices (bio-composite). So, untreated and treated Diss fibers by chemical (soda, silane and acetic acid) and thermal treatment have been manually extracted and characterized to evaluate their surface condition as well as their chemical composition, their mechanical properties and their thermal stability. The obtained results have shown many advantages look promising for such an application, especially the fact that the Diss fiber bundles has small diameter (89 ± 22 μm), a rough surface with the presence of thorns, a low density of 0.93 g/cm3, and a tensile strength that can reach 270 MPa. Furthermore, all the treatments adopted have shown improvements regarding the fibrillation of fiber bundles (could reach −40% for the diameter), their surface state, their thermal stability and their mechanical behavior (could reach +60% for Young’s modulus and +15% for tensile stress)