Dredged Marine Sediments Geotechnical Characterisation for Their Reuse in Road Construction

A large Research European Interreg IVA Program called "Sustainable Environmental Treatment And Reuse of Marine Sediment" is running in order to better understand the Channel sediment characteristics and to develop and promote sustainable management practices for marine sediments. A total of 13 sediments localized along the Manche channel were sampled and analyzed for SETARMS project. A comprehensive series of laboratory tests were performed to characterize different sediments and to class them from a geotechnical point of view according to the French standard GTR. This will be necessary to evaluate the potential use of treated sediments. Then to determine, with GTS French guide recommendations the appropriate formulation using hydraulic binders in order to improve sediments mechanical properties. This paper presents and discusses results of physical and geotechnical characterization of different sediments sampled from different French ports. Geotechnical characterization results show that sediments are classified as fine and plastic materials with low to high organic matter content. Knowing that the variability of the sediments characteristics is one of the limits to their reuse in geotechnical applications, the results will be presented and put in prospect towards this variability and the reuse of sediment as a subgrade layer

Experimental study on the reuse of a dredging sludge from west of Algeria in brick fabrication

The siltation as a natural phenomenon threatens the performance of harbors by reducing their docking volume compared to dams in terms of water storage, as well as their life span. An alarming rate of siltation is noted in the various basins requires an urgent cleaning operations. In a context of valorization of the sludge resulted from the dredging operations of the basins of the Oran’s port and those of the Bouhanifia’s dam which are  located in Western Algeria, it is a question of studying possibilities which are offered by the use of these vases in the design of bricks building. The followed methodology is based on a physicochemical and mineralogical characterization of the two vases to reveal the one closest to the standards recommended for the manufacture of the baked brick. After analyzing sediments dredged in the port of Oran, it turned out that there is a dominance of sandy sediments, which are not recoverable in the areas of bricks we have targeted. Sustainability tests were performed on several sludge dam samples at different temperatures and percentages of water. The results gave a satisfaction in mechanical strength and durability for a firing temperature of 850 ° C and a percentage of water of 20%

Experimental study on the reuse of a dredging sludge from west of Algeria in brick fabrication

The siltation as a natural phenomenon threatens the performance of harbors by reducing their docking volume compared to dams in terms of water storage, as well as their life span. An alarming rate of siltation is noted in the various basins requires an urgent cleaning operations. In a context of valorization of the sludge resulted from the dredging operations of the basins of the Oran’s port and those of the Bouhanifia’s dam which are  located in Western Algeria, it is a question of studying possibilities which are offered by the use of these vases in the design of bricks building. The followed methodology is based on a physicochemical and mineralogical characterization of the two vases to reveal the one closest to the standards recommended for the manufacture of the baked brick. After analyzing sediments dredged in the port of Oran, it turned out that there is a dominance of sandy sediments, which are not recoverable in the areas of bricks we have targeted. Sustainability tests were performed on several sludge dam samples at different temperatures and percentages of water. The results gave a satisfaction in mechanical strength and durability for a firing temperature of 850 ° C and a percentage of water of 20%

Self-compacting Backfills using Fly Ash and Dredged Marine Sediments for Public Work Applications

Sediment accumulation at the bottom of ports disrupts maritime activities and disturbs the physicochemical balance of water bodies. In France, the maintenance of the 6500-kilometer long coastline would require the extraction of about 50 million m3 of marine sediments every year. For several years, these sediments were considered waste. However, they are increasingly being acknowledged as a resource in need of management. Several research studies were conducted to find valorization ways that satisfy technical and regulatory requirements. These sediments present interesting heterogeneous physicochemical, mineralogical, and geotechnical characteristics. However, they may contain contamination, which could limit their uses. This paper deals with the possibility of producing self-compacting backfills using dredged marine sediments, fly-ash, and hydraulic binders for public work applications. The impact of dredged sediments on the composition of self-compacting backfills was studied. Moreover, the impact of fly ash and binder type and percentage on the backfill behavior and mechanical properties was discussed

Marine Dredging Sediments Valorization in Self-Compacting Concretes

Rock and eroded soil are transported by wind, tide, and human action (development works), and deposited as sediment in ports, estuaries, and rivers. The sediment accumulation at the bottom of ports disrupts maritime activities and disturbs the physicochemical balance of water bodies. As a result, dredging is necessary to reduce sediment deposits and restore the natural environment for proper port functioning. At the national level, the maintenance of the 6,500-kilometer French coastline would require the extraction of about fifty million cubic meters of marine sediment every year. These dredged sediments have been used in civil engineering applications for about ten years, in order to reduce their economic and environmental impact. The proposed study addresses the potential use of sediments to produce accropode blocks for maritime public works applications. It consists in developing concrete mixtures using dredged marine sediment treated to protect against erosion. A study of material characterization, optimization of the composition of the concrete formulation, as well as a determination of the mechanical, physical and durability properties of the concrete were necessary to validate the technical feasibility of this new solution. Around 700 small accropode blocks were then prepared to better analyze the structure stability against swell effects. The obtained results show that the sediments could not produce Self Compacting Concrete (SCC). However, sediment treatment with 6% by weight of cement has enabled the production of SCC. It is worth noting that the use of superplasticizer was essential to ensure concrete workability. Increasing the cement percentage has also improved the composite workability. Finally, a concrete compressive strength greater than 40 MPa has been achieved when using 300 kg/m3 of treated sediments

Experimental study on the reuse of a dredging sludge from west of Algeria in brick fabrication

The siltation as a natural phenomenon threatens the performance of harbors by reducing their docking volume compared to dams in terms of water storage, as well as their life span. An alarming rate of siltation is noted in the various basins requires an urgent cleaning operations. In a context of valorization of the sludge resulted from the dredging operations of the basins of the Oran’s port and those of the Bouhanifia’s dam which are  located in Western Algeria, it is a question of studying possibilities which are offered by the use of these vases in the design of bricks building. The followed methodology is based on a physicochemical and mineralogical characterization of the two vases to reveal the one closest to the standards recommended for the manufacture of the baked brick. After analyzing sediments dredged in the port of Oran, it turned out that there is a dominance of sandy sediments, which are not recoverable in the areas of bricks we have targeted. Sustainability tests were performed on several sludge dam samples at different temperatures and percentages of water. The results gave a satisfaction in mechanical strength and durability for a firing temperature of 850 ° C and a percentage of water of 20%

Essais d’aptitude au traitement des sédiments de dragage marins en vue de leur valorisation en techniques routières

International audienceIn this paper, results for an European project called SETARMS which aims to find innovative and sustainable solutions for marine dredged sediments in order to reuse them in road construction. After a first stage of a geotechnical characterization of sediments according to the GTR, the GTS recommendations were adopted to treat sediments with hydraulic binders. Hence, a formulation composed of 3% of quicklime and 6% of cement was applied for height different sediments. Specific ability tests were conducted in order to measure volumetric swelling and indirect tensile strength. Obtained results show that even if raw sediments belong to the same GTR class (A1 or A2), the treated samples respond differently to the adopted treatment formulation. Results of mechanical performance with the cure age show that most sediments don’t reach the needed criteria for reuse as sub-grade layer.Les résultats présentés dans cet article s’inscrivent dans le cadre du projet de recherche Européen SETARMS dont l’un des objectifs consiste à trouver des solutions innovantes et durables pour la gestion des sédiments marins dragués en Manche (France-Angleterre) pour une application en techniques routières, plus particulièrement en couche de forme. Après une 1ère étape de caractérisation géotechnique des sédiments de dragage selon le GTR, les recommandations du GTS ont été utilisées pour le traitement des sédiments aux liants hydrauliques. Ainsi une formulation à 3 % de chaux et 6 % de ciment est appliquée à huit sédiments. Des essais d’aptitude au traitement comprenant des mesures de gonflements volumiques (Gv) et de résistances à la traction indirecte (Rit) ont été réalisés sur les huit sédiments traités en adoptant les normes standards en vigueur en France. Les résultats obtenus montrent que malgré une même origine des sédiments et des classes GTR assez proches (A1 et A2), les sédiments traités répondent différemment aux essais d’aptitude. Ces premiers résultats, utiles à l’avancement du projet, permettent une meilleure compréhension de la problématique de traitement des sédiments aux liants hydrauliques et leur valorisation en techniques routières

Valorization of Dredged Sediments in Manufacturing Compressed Earth Blocks Stabilized by Alkali-Activated Fly Ash Binder

International audienceThe valorization of dredged sediments is a promising solution to reduce the strain on natural resources, which is in line with sustainable development goals. This study aims to evaluate the potential valorization of dredged sediment in manufacturing compressed earth blocks (CEBs). The CEBs were stabilized by a combination of fly ash (FA) with sodium hydroxide (NaOH). The stabilization was achieved by partial substitution of sediment for fly ash with six different percentages 10, 20, 30, 40, and 50% by weight. The CEBs samples were characterized in terms of structural, microstructural, mechanical, and thermal properties. The results showed that increasing FA content significantly improves the mechanical strength of CEBs, dry compressive strength ranges from 2.47 MPa to 9 MPa, whereas wet compressive strength ranges from 0.95 MPa to 6.9 MPa. The mechanical performance is related to the amount of alkali-activated fly ash gels, which bind the sediment grains and makes the CEBs more compact and resistant. The optimal dosage of alkali-activated fly ash to replace the sediment was between 10 and 20%. In this substitution range, mechanical performance and physical properties improved significantly. In addition, the thermal properties varied slightly with alkali-activated FA content

Mineral waste valorization in road subgrade construction: Algerian case study based on technical and environmental features

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