En France, les volumes de sédiments de dragage générés chaque année pour la maintenance des ports et des voies navigables sont estimés à environ 50 millions de mètres cubes. La gestion de ces sédiments représente un enjeu économique, social et environnemental pour les gestionnaires. Aujourd’hui, l’une des solutions privilégiées est le développement de la gestion à terre de ces matériaux, qui consiste à les réutiliser comme matières premières secondaires en substitution partielle ou totale de matières nobles. De nombreux travaux de recherche ont été effectués sur la problématique de la valorisation des sédiments de dragage et de curage et de nouvelles filières sont actuellement toujours à l’étude (ciments, enrochements pour travaux maritimes et fluviaux, bétons cellulaires, granulats artificiels, etc.). Ce travail de thèse s’inscrit dans un contexte d’économie circulaire et vise à permettre le développement d’une gestion durable et responsable des ressources naturelles non renouvelables. Ceci à travers la réutilisation des sédiments de dragage dans la formulation de matériaux composites traités par des liants thermodurcissables ou thermoplastiques. Ainsi, après un travail de synthèse bibliographique sur les principales propriétés des sédiments de dragage, les méthodes de formulation des mortiers polymères et les modalités d’intégration des matériaux alternatifs dans ces matrices sont été décrites. Les expérimentations portent plus particulièrement sur la formulation de matériaux à partir de polymères thermodurcissables (résines de type Epoxy ou Polyester) et thermoplastiques (plastiques recyclés issus du tri des déchets). La validation des performances techniques des formulations optimisées pour chacun des traitements a été effectuée pour des usages en revêtements de sols ou en granulats légers dans des bétons hydrauliques. Enfin, la dernière partie de la thèse a été consacrée à l’étude de l’acceptabilité environnementale des nouveaux matériaux à travers la réalisation des essais de lixiviation dynamique sur monolithes. Les travaux menés ont permis de démontrer la faisabilité technique et environnementale de la valorisation des sédiments en tant que charge minérale dans des matrices polymères, avec des taux d’incorporation de sédiments significatifs pouvant atteindre jusqu’à 80 %. Ce qui confirme l’intérêt de cette typologie de traitement pour la valorisation des sédiments de dragage. / In France, the volume of dredged sediments generated each year through maintenance of ports and waterways, is estimated at around 50M cubic meters. The management of these sediments represents an economic, social and environmental stake for the managers of the waterways. Today, one of the solution is the onshore management of these sediments, which consists on their reuse as secondary raw materials in partial or total substitution of natural materials for civil engineering applications such as sub-base road materials, embankments, concrete, bricks/tiles, and cement production. In this context this study was initiated in order to define a long-term value chain for dredging sediments for a sustainable and responsible management of natural resources. This through the valorization of dredged sediments in polymer matrix mortar formulations. Indeed, this research presents an innovative solution that preserves natural resources by promoting the use of local resources, such as dredged sediments. In order to achieve this objective, the study included several phases : the first part is devoted to the state of the art concerning dredged sediments, polymer mortars and the recovery of waste in polymer mortars. In the second part, we studied recovery of sediment in thermosetting matrix polymers (Epoxy-Polyester). In the third part we studied the possibilities of incorporating sediments in recycled thermoplastic matrix. The materials from this combination have been used as lightweight aggregates for mortar formulation. Finally, in the last part was devoted to environmental monitoring of new formulated materials. This is done through leaching tests carried out on crushed samples and monoliths, to ensure the environmental safety of these materials. The result obtained with the different formulations tested, show the technical and environmental feasibility of valorization of sediments as mineral filler in polymer mortars, with sediments incorporation rates range between 50 and 80%. Indeed, the use of a polymer matrix makes it possible to have better physico-mechanical and chemical results with cementitious matrix mortars.

This article reports the successful manufacturing of hybrid yarns from virgin staple CF (40 or 60 mm) or recycled staple CF (rCF) by mixing with polyamide 6 (PA 6) fibers of defined length. The hybrid yarns are produced using an optimized process route of carding, drawing, and flyer machine. Furthermore, the influence of CF length, CF type (i.e. virgin or rCF), CF volume content, and twist of the yarn are also investigated regarding the tensile properties of unidirectionally laid (UD) thermoplastic composites. The results show that CF length, yarn twist, and CF content of composites play a big role on the tensile properties of thermoplastic composites. From the comparison of tensile strength of UD composites produced from 40 and 60mm virgin staple CF, it can be seen that the increase of yarn twist decreases the tensile strength. However, the effect of twist on the tensile properties of UD composites manufactured from 40mm virgin staple CF is insignificant. The tensile strength of UD thermoplastic composites manufactured from the hybrid yarn with 40 and 60mm virgin staple CF and rCF is found to be 771 ± 100, 838 ± β1, and 801 ± 53.4 MPa, respectively, in the case of 87 T/m containing 50 volume% CF.

El ángulo de fricción y la cohesión son parámetros de resistencia al corte establecidos por el modelo de Morh Coulomb, siendo estos necesarios para el diseño de estructuras geotécnicas utilizadas tanto en obras civiles como en obras mineras. Si durante la investigación geotécnica se concluye que las características de resistencia del material son menores a los requeridos, entonces es necesario realizar mejoras en terreno de fundación. Una de estas mejoras corresponde al uso de partículas PET, la misma que es mezclada con el suelo del terreno natural, obteniéndose un suelo con mejores características geotécnicas. El uso de las partículas PET como material de reforzamiento mecánico del suelo, nace de la necesidad técnica de obtener mejores características en el suelo y la búsqueda de reducir el impacto ambiental. La presente investigación busca encontrar el porcentaje óptimo de PET, que mejore el comportamiento geotécnico de un suelo gravoso arcilloso. Se preparó 5 probetas, donde se mezcló el suelo con porcentajes de 1%, 1.5%, 2%, 2.5% y 3 % de PET. Mediante el ensayo de corte directo se estimó la influencia del PET en la resistencia al corte del suelo. Los resultados obtenidos demuestran que el 2% de PET añadido a la grava arcillosa, aumenta la resistencia al corte en un 8.3% respecto al suelo sin refuerzo. / The angle of friction and cohesion are parameters of resistance to cutting that define the characteristics of the soil in civil works and buildings. If during the elaboration of a project, the soil does not comply with the necessary requirement, the way to improve or stabilize the soil to be used in the work is sought. The use of PET particles as a material for mechanical reinforcement of the soil, arises from the technical need to obtain better characteristics in the soil and the search to reduce the environmental impact. The present research seeks to find the optimal percentage of PET, which improves the geotechnical behavior of a clayey soil. Five test pieces were prepared, where the soil was mixed with percentages of 1%, 1.5%, 2%, 2.5% and 3% of PET. Through the direct cut test you will find the variation of the cut resistance generated by adding PET particles. The results obtained will be analyzed to understand the influence of the addition of recycled PET waste on the cut resistance of a clayey soil. / Tesis

La retracción es un fenómeno que afecta el proceso de fraguado y la vida útil del concreto con la aparición de fisuras; en los últimos años se han generado estudios y métodos para mitigarlo y controlarlo con el uso de diferentes productos y métodos. El desarrollo de infraestructuras viales con el uso de concreto como carpeta de rodadura, requiere de métodos para garantizar la durabilidad y disminuir las afectaciones por los esfuerzos incorporados por el uso, condiciones climáticas, base de soporte y restricciones de movimiento de la estructura. A pesar del conocimiento de este fenómeno, existe poco desarrollo técnico para medirla, estudiarla y controlarla. Por lo descrito anteriormente, surge la necesidad de investigar, ampliar el conocimiento y buscar métodos experimentales para medir y comprender el comportamiento de la contracción en el concreto usado en pavimentos. El proyecto de investigación académica busca evaluar los efectos de las fibras sintéticas recicladas de polipropileno en los ensayos de contracción- retracción plástica (ASTM C 1579), y se plantea la preparación de 3 diseños de mezclas con diferentes relaciones de fibras sintéticas recicladas y vírgenes. Existen otros métodos de evaluación (contracción libre y contracción restringida) para precisar los efectos de las fibras sintéticas en la aparición de fisuras en estado plástico y endurecido, quedarán propuestos para realizar las demostraciones en futuras investigaciones. / Use of synthetic fibers of recycled polypropylene to control the fissures generated by retraction in concrete pavements in Lima. The retraction is a phenomenon that affects the setting process and the life of the concrete with the appearance of cracks; In recent years, studies and methods have been generated to mitigate and control it with the use of different products and methods. The development of road infrastructures with the use of concrete as a rolling folder requires methods to guarantee durability and reduce the effects of the efforts incorporated by the use, climatic conditions, support base and movement restrictions of the structure. Despite the knowledge of this phenomenon, there is little technical development to measure, study and control it. As described above, the need arises to investigate, expand knowledge and seek experimental methods to measure and understand the behavior of contraction in the concrete used in pavements. The academic research project seeks to evaluate the effects of recycled synthetic fibers of polypropylene in the contraction-plastic shrinkage tests (ASTM C 1579), and the preparation of 3 designs of mixtures with different ratios of recycled and virgin synthetic fibers is proposed. There are other methods of evaluation (free contraction and restricted contraction) to specify the effects of synthetic fibers in the appearance of cracks in plastic and hardened state, will be proposed to perform the demonstrations in future research / Tesis

L'industrie de la fibre de carbone connaît actuellement une forte croissance, passant d'une demande annuelle mondiale de 18 000 tonnes en 2001 à 48 000 tonnes en 2013. Entre l'important gisement de déchets composites à valoriser et les différentes mesures législatives françaises et européennes prises en faveur d'une gestion durable des déchets, le recyclage des composites carbone (PRFC - Polymères Renforcés de Fibres de Carbone) offre d'intéressantes perspectives environnementales et économiques. L'objectif de ce travail de thèse est d'obtenir des composites thermoplastiques à partir de fibres de carbone recyclées. Des fibres de carbone ont ainsi été récupérées du traitement par vapo-thermolyse de composites à matrice époxyde fabriqués par LRI (Liquid Resin Infusion). La vapo-thermolyse est un procédé thermochimique utilisant la vapeur d'eau surchauffée à pression atmosphérique pour la dégradation de la matrice organique des composites et la récupération des fibres de carbone. De prime abord, l'étude des propriétés des fibres montre que le procédé est particulièrement efficace pour dégrader la résine tout en préservant les propriétés mécaniques des fibres récupérées. Deux voies de formulation sont alors proposées. La première concerne l'élaboration de granulés thermoplastiques pour l'injection ; la seconde l'élaboration de mats à orientation aléatoire pour la fabrication de TRE (Thermoplastique Renforcé Emboutissable). L'étude des propriétés mécaniques des composites ainsi élaborés montre des résultats comparables à ceux obtenus pour des matériaux élaborés à partir de fibres vierges. La fibre de carbone recyclée par vapo-thermolyse constitue donc une fibre compétitive en tant que renfort pour des composites thermoplastiques à fibres courtes. / World need in carbon fibre grew from 18,000 tons per year in 2001 to 48,000 tons in 2013. With the increasing amount of composite waste and the recent French or European legislation focus towards a sustainable waste management, carbon fibre composites recycling offers interesting economic and environmental perspectives. This project aims at enabling the manufacturing of thermoplastic composites from recycled carbon fibres. To reach this goal, PAN-based carbon fibres were recycled from epoxy resin/carbon fibre composites by steam-thermolysis. It is a thermochemical process using superheated steam at environmental pressure to degrade the organic matrix of composites and thus to recover carbon fibres. Reclaimed carbon fibres were first studied so as to show that the steam-thermal process is particularly efficient to degrade the epoxy resin of composites while maintaining fibres mechanical properties. Two kinds of composites were then considered: short-fibre reinforced compounds for injection and randomly-oriented fibre mat reinforced thermoplastics. Their mechanical properties were studied and results show that mechanical performances of recycled carbon fibre-based composites are similar to those of virgin carbon fibre-based composites. Steam-thermolysis recycled carbon fibre is a competitive fibre while being used as reinforcement for short fibre reinforced thermoplastics.

Det här examensarbetet ifrågasätter och undersöker vår användning och återanvändning av plaster, och går sedan vidare med att gestalta en sittmöbel i återanvänd och återvunnen plast. Syftet är att lyfta materialen, problematiken, och påvisa att vi faktiskt kan ge materialen fler liv. Plaster har revolutionerat våra samhällen och gjorde det modena livet möjligt, men vår linjära och därför också bristfälliga hantering av dem har gjort att de nu kommit att göra otroligt stor skada. Plaster är material som tillhör den tekniska sfären, men på grund av att de inte hålls där gör de skada i den biologiska sfären och allt som lever i den. Vi behöver ta ansvar och angripa problemet från flera olika håll samtidigt. Återvinning och återanvändning är två av många sätt. Syftet med arbetet är att ge nytt liv till två typer av plastavfall. Dels återvunnen plast (kylskåp och tangentbord) i form av skivmaterial från The Good Plastic Company, och det andra är återanvänd täckplast (engångsalternativ till pressening) från Bullandö marina AB.

The availability of a considerable amount of waste carbon fiber (CF) and the increased pressure to recycle/reuse materials at the end of their life cycle have put the utilization of recycled CF (rCF) under the spotlight. This article reports the successful manufacturing of hybrid yarns consisting of staple CF cut from virgin CF filament yarn and polyamide 6 fibers of defined lengths (40 and 60 mm). Carding and drawing are performed to prepare slivers with improved fiber orientation and mixing for the manufacturing of hybrid yarns. The slivers are then spun into hybrid yarns on a flyer machine. The investigations reveal the influence of fiber length and mixing ratio on the quality of the card web, slivers and on the strength of the hybrid yarns. The findings based on the results of this research work will help realize value-added products from rCF on an industrial scale in the near future.

El desarrollo tecnológico del sector construcción ha permitido incursionar en nuevas técnicas de procesos constructivos, implementación de nuevos productos, y el desarrollo de nuevas tendencias en la industria de la construcción. Actualmente, una de las prioridades de esta industria es el desarrollo social, pero con visión y conceptos de preservación del medio ambiente. En ese sentido, la presente investigación busca mejorar la resistencia mecánica de los muros portantes de las viviendas informales de Lima Este, mediante la implementación de un nuevo producto con mejor desempeño mecánico, sobre todo con uso de materiales reciclados y amigable con el ambiente. Desde muchos años, Lima ha pasado por varias crisis de migraciones, los cuáles han dejado al descubierto la falta de planificación urbanística para brindar espacios seguros y sobre todo ha dado paso al sector informal de la construcción. Sumado a ello la falta de asesoramiento profesional se obtiene un panorama poco favorable al bienestar y seguridad de las familias frente a desastres naturales. La fibra de coco, la ceniza de cáscara de arroz y el uso de concretos reciclados como agregados, prometen un mejor desempeño de los muros portantes en el sentido de soportar mejor las cargas muertas y vivas de una vivienda; asimismo, un mejor desarrollo ante esfuerzos de corte. La metodología de esta investigación se basa en la evaluación y diseño de mezclas, para identificar los porcentajes de reemplazos óptimos y sus respectivos parámetros de diseño, de manera que se cumplan con el marco normativo. / The technological development of the construction sector has allowed us to venture into new techniques of construction processes, implementation of new products, and the development of new trends in the construction industry. Currently, one of the priorities of this industry is social development, but with a vision and concepts of environmental preservation. In this sense, the present research seeks to improve the mechanical resistance of the bearing walls of informal homes in East Lima, by implementing a new product with better mechanical performance, especially with the use of recycled materials and friendly with the environment. For many years, Lima has gone through several migration crises, which have increased the lack of urban planning to provide safe spaces and, above all, it has given way to the informal construction sector. In addition to the lack of professional advice, an unfavorable picture is obtained of the well-being and safety of families in the face of natural disasters. Coconut fiber, rice husk ash and the use of recycled concrete as aggregates, promise better performance of load-bearing walls in the sense of better supporting the dead and live loads of a home; likewise, a better development before tensile stresses. The methodology of this research is based on the evaluation and design of mixtures, to identify the percentages of optimal replacements and their respective design parameters, so that they comply with the regulatory framework. / Tesis

Recycled concrete is among the rising eco-friendly construction materials which helps to reduce waste and the need for new natural resources. However, such concrete may present previous deterioration due to, for instance, alkali-silica reaction (ASR), which is an ongoing distress mechanism that may keep being developed in the recycled material. This work aims to evaluate the potential of further distress and crack development (i.e. initiation and propagation) of AAR-affected RCA concrete in recycled mixtures displaying distinct past damage degrees and reactive aggregate types. Therefore, concrete specimens incorporating two highly reactive aggregates (Springhill coarse aggregate and Texas sand) were manufactured in the laboratory and stored in conditions enabling ASR development. The specimens were continuously monitored over time and once they reached marginal (0.05%) and very high (0.30%) expansion levels, they were crushed into RCA particles and re-used to fabricate RCA concrete. The RCA specimens were then placed in the same previous conditions and the “secondary” ASR-induced development monitored over time. Results show that the overall damage in ASR-affected RCA concrete is quite different from affected conventional concrete, especially with regards to the severely damaged RCA particles, where ASR is induced by a reactive coarse aggregate, as the RCA particle itself may present several levels of damage simultaneously caused by past/ongoing ASR and newly formed ASR. Moreover, the influence of the original damage extent in such RCA concrete was captured by the slightly damaged RCA mixture eventually reaching the same damage level as the severely damaged mixture. Furthermore, the original extent of deterioration influence the “secondary” induced expansion and damage of RCA concrete since the higher the original damage level, the higher the cracks numbers and lengths observed in the RCA concrete for the same expansion level whereas wider cracks are generated by RCA having previously been subjected to slight damage thus indicating the difference in the distress mechanism as a function of original extent of damage. In addition, it has been found that distress on RCA containing a reactive sand generates and propagates from the residual mortar (RM) into the new mortar (NM) as opposed to RCA containing a reactive coarse aggregate, being generated and propagated from the original coarse aggregate (i.e. original virgin aggregate – OVA) into the NM. Likewise, RCA containing a reactive sand caused longer and higher number of cracks for the same “secondary” induced expansion than the RCA made of reactive coarse aggregate. Finally, novel qualitative and descriptive models are proposed in this research to explain ASR-induced distress generation and propagation on RCA mixtures made of reactive fine and coarse aggregates.

River discharge leads to extensive phytoplankton blooms often observed in ocean color satellite images to extend far into the open ocean as high chlorophyll plumes. We investigated diversity, distribution and ecology of phytoplankton populations in the Mississippi River plume, both spatially and in the water column using molecular tools. A method was developed for the quantification of diatom/pelagophyte rbcL (large subunit of Ribulose-1,5-bisphosphate Carboxylase/Oxygenase) mRNA using quantitative PCR and applied to cultures and in the plume. The vertical structure of phytoplankton species in the Mississippi River plume was described by flow cytometry, pigments, rbcL mRNA and rbcL cDNA libraries. High productivity in the plume was associated with a large population of Synechococcus and elevated levels of cellular form IA rbcL mRNA. rbcL cDNA libraries indicated two vertically separated clades of Prochlorococcus (high-light and low-light adapted) in addition to a diverse group of prymnesiophytes and a microdiverse clade of prasinophytes, which may have dominated the SCM (Subsurface Chlorophyll Maximum). In situ sampling and satellite image analysis were used to estimate that the plume accounted for 41% and 13% of all surface water column ix productivity in the oligotrophic Gulf of Mexico, while covering less than 3% of its area. Coastally the plume is dominated by diatoms, which are replaced by a bloom of Synechococcus as the plume moves offshore. Diatoms as indicated by pigments and rbcL clone libraries again dominated the offshore, least productive plume. 15N uptake measurements indicated that rapid recycling of ammonium despite higher levels of nitrate primarily drives production in the offshore plume. rbcL mRNA levels and photosynthetic capacity displayed strong diel patters in three out of four time series sampled during the GRIST (Geochemical Rate/mRNA Integrated Study). In addition it was demonstrated that transcriptional regulation of the global nitrogen regulatory protein NtcA in Synechococcus WH7803 may involve a small cis-encoded anti-sense mRNA. Methods for the generation of large insert BAC (Bacterial Artificial Chromosome) from cultures and the environment were refined. Partial sequencing and genomic comparison of an ntcA containing BAC clone obtained from Synechococcus WH7803 indicated that ntcA is not part of a larger nitrogen assimilation operon in cyanobacteria.