Recycling of dredged sediments in self-consolidating concrete: mix design optimization and durability study

La demande en matériaux de construction a considérablement augmenté, dont la grande majorité est d’origine naturelle. Étant donné que ces matériaux ne sont pas renouvelables, il est essentiel de trouver des matériaux alternatifs. Les études récentes menées à l’IMT Lille Douai ont montré que les matériaux issus de dragage possèdent des propriétés pouzzolaniques intéressantes et peuvent être utilisées comme ajouts cimentaires alternatifs ou comme filler. Vu le volume important dragué annuellement, cette valorisation aura des impacts environnementaux et économiques très positifs. Les objectifs visés dans cette recherche portent sur : la valorisation des sédiments du Grand Port Maritime de Dunkerque (France) dans des bétons autoplaçants (BAPs) comme ajouts cimentaires ; la valorisation des sédiments fluviaux du Château de l’Abbaye (France) dans des mortiers comme ajouts cimentaires afin d’évaluer la mobilité et la stabilité des éléments traces métalliques ; la solidification des sables dragués des Iles-de-la-Madeleine (Québec) par liant hydraulique afin de produire des roches artificielles. Dans l'ensemble, les résultats de ce travail sur les sédiments mettent en exergue la contribution substantielle de ces matériaux à l’amélioration des performances des bétons et supportent leur emploi comme ajouts cimentaires. Ces résultats contribuent à réduire l’empreinte du CO2 dans le béton, ainsi que les exploitations minières. Ils permettent également de mieux comprendre le comportement des sédiments dans les bétons à partir de certaines analyses et traitements, et d’identifier les milieux agressifs convenables à l’utilisation des sédiments.Abstract: The demand for building materials has increased enormously, and the vast majority are of natural origin. Since these materials are not renewable, it is essential to find alternatives. Recent studies at the IMT Lille Douai have shown that dredged materials have interesting pozzolanic properties and can be used as alternative cement additions or as filler. Given the large volume dredged annually, this recovery will have very positive environmental and economic impacts. The objectives of this research relate to: (1) The recycling of sediments from Grand Port Maritime de Dunkerque (France) in self-consolidating concrete (SCCs) as Supplementary cementitious materials (SCMs); (2) The recycling of fluvial sediments of Château l’Abbaye (France) in mortars as SCMs in order to assess the mobility and stability of heavy metal elements; (3) The solidification of the dredged sands of Iles-de-la-Madeline (Quebec) by hydraulic binder in order to produce artificial rocks. Overall, the results of this work on sediments highlight the substantial contribution of these materials to improving the performance of concrete and support their use as SCMs. These results contribute to reducing the footprint of CO2 in concrete, as well as mining. Also, contributes to understanding the behavior of sediments in concrete from certain analyzes and treatment. Thus, identify aggressive environments suitable for the use of sediments

Prediction of Self-Consolidating Concrete Properties using XGBoost Machine Learning Algorithm: Part 1–Workability

The Interest in Implementing Self-Consolidating Concrete (SCC) in Major Construction Projects Has Increased Significantly in Recent Years. This Paper Reports the Results of an Extensive Survey of Experimental Data of More Than 1700 SCC Mixtures from over 100 Studies Published in the Last Decade. the Survey Included the SCC Mixture Proportioning, Key Fresh Properties Including Flowability, Passing Ability, and Segregation Resistance, as Well as Some of the Derived Properties (E.g., Paste Volume). the Statistical Analysis of the Reported Parameters Showed Wide Variations in Values. the Outcome of the Survey Indicates that SCC Mixture Design and Workability Properties Do Not Systematically Lie within the Recommendations Reported in Various Guidelines. a Wide Range of Workability Tests is Used; However, only 22 % of the Studies Reported Values for Segregation Resistance. the Slump Flow Test Was the Most Tested Fresh Property and the Most Reported Values Are in Range of 591–760 Mm (X¯ = 679 Mm). the V-Funnel Time Was the Second Most Reported Test, and the Most of Reported Values Are in Range of 4.0–20 S (X¯ = 11 S). the Study Devised and Evaluated the Efficacy of using Machine Learning (ML) Models, Namely Extreme Gradient Boosting (XGBoost), to Predict the Two Most Reported Workability Characteristics of SCC, Namely Slump Flow and V-Funnel Flow Time. the Model Was Formulated to Predict Slump Flow and V-Funnel Time using a Refined Sub-Database of 852 Tests (The Extreme Data I.e., 5 % from Each Side, for the Both Properties and the Empty Data Was Deleted). the Findings Revealed that the XGBoost Model Can Provide an Accurate Prediction for the Slump Flow and V-Funnel Values, Thus Indicating its Potential as a Powerful Tool for SCC Optimization. the Findings Provide Valuable Insights into the Application of ML in SCC Research and Contribute to the Development of More Efficient and Sustainable Construction Practices

Characterizations and Potential Recovery Pathways of Phosphate Mines Waste Rocks

The Phosphate Ore Production is Steadily Increasing Due to its High Demand for Agriculture, Medicine, and Others. Ore Extraction Generates a Considerable Quantity of Waste Rocks that Are Generally Stocked in Piles. the Current Research Aims to Investigate the Characterization of Phosphate Mine Waste Rocks (PMWR) Generated in Benguerir, Morocco Mine Site. as a Part of a Wide Project Aiming to Recycle Those Stockpiles, Sensor-Based Ore Sorting Will Be Employed to Separate the Different Lithologies. as a Prior Investigation Before Implementing This Technology, Two Samples of 25 Tons from the Destoning and Screening PMWR Piles Were Sampled and Submitted to Manual Sorting. the Latter Operation Revealed the Presence of Different Lithologies Including Indured Phosphate, Different Types of Siliceous, Carbonate, Phosphorus, and Marly Rock Types. Those Waste Rocks Were Characterized Physically, Chemically, and Mineralogically. their Potential Uses for Recycling or Upcycling Was Investigated and Addressed. About 25% of Indured Phosphate Was Found, Which Can Be First Recovered by Ore Sorting. This Reserve of Residual Phosphate Could Be Recovered using Beneficiation Methods. the Flintstone, Phosphated Flintstone, and Dolomitic Limestone Exhibit Good Physical and Mechanical Properties that Meet the Requirements to Produce Concrete. the Silexite and Siliceous Marls Have a Low Density and Could Be Used as Lightweight Aggregate for Non-Structural Concrete Blocks Production. the Investigation on Tender Marls Corroborates the Literature and their Suitability as Alternative Binders or as Supplementary Cementitious Materials. Those Marls Could Be Used as Well as Lime Binder for Repairing Historical Buildings or as Hydraulic Lime Binder for Road Construction. PMWR Valorization as Road Construction Materials Was Already Proved. However, Studying This Remediation Pathway after the Recovery of Phosphate and Other Lithologies by Ore Sorting is Highly Recommended. the Recycling of Those By-Products Will Decrease the Natural Resources Consumption in the Civil Engineering Field Alongside with Resolving their Environmental Problems

Valorisation des sédiments de dragage dans des bétons autoplaçants : optimisation de la formulation et étude de la durabilité

The demand for building materials has increased enormously, and the vast majority are of natural origin. Since these materials are not renewable, it is essential to find alternatives. Recent studies at IMT Lille Douai have shown that dredged materials have interesting pozzolanic properties and can be used as alternative cement additions or as filler. Given the large volume dredged annually, this recovery will have very positive environmental and economic impacts.The objectives of this research relate to: (1) the recycling of sediments from Grand Port Maritime de Dunkerque (GPMD, France) in self-consolidating concrete (SCCs) as supplementary cementitious materials (SCMs); (2) the recycling of fluvial sediments of Château l'Abbaye (France) in mortars as SCMs in order to assess the mobility and stability of heavy metal elements; (3) the solidification of the dredged sands of Iles-de-la-Madeline (Quebec) by hydraulic binder in order to produce false rocks which aim to play the role of the bumper against coastal erosion.Overall, the results of this work on sediments highlight the substantial contribution of these materials to improving the performance of concrete and support their use as SCMs. These results contribute to reducing the footprint of CO2 in concrete, as well as mining. Also, contributes to understanding the behavior of sediments in concrete from certain analyzes and treatment. Thus, identify aggressive environments suitable for the use of sediments.La demande en matériaux de construction a considérablement augmenté, dont la grande majorité est d’origine naturelle. Etant donné que ces matériaux ne sont pas renouvelables, il est essentiel de trouver des matériaux alternatifs. Les études récentes menées à l’IMT Lille Douai ont montré que les matériaux issus de dragage possèdent des propriétés pouzzolaniques intéressantes et peuvent être utilisées comme ajouts cimentaires alternatifs ou comme filler. Vu le volume important dragué annuellement, cette valorisation aura des impacts environnementaux et économiques très positifs.Les objectifs visés dans cette recherche portent sur : la valorisation des sédiments du Grand Port Maritime de Dunkerque (GPMD, France) dans les bétons autoplaçants (BAPs) comme ajouts cimentaires ; la valorisation des sédiments fluviaux du Château l’Abbaye (France) dans des mortiers comme ajouts cimentaires afin d’évaluer la mobilité et la stabilité des éléments traces métalliques ; la solidification des sables dragués des Iles-de-la-Madeline (Québec) par liant hydraulique afin de produire des roches artificielles.Dans l’ensemble, les résultats de ce travail sur les sédiments mettent en exergue la contribution substantielle de ces matériaux à l’amélioration des performances des bétons et supportent leur emploi comme ajouts cimentaires. Ces résultats contribuent à réduire l’empreinte du CO2 dans le béton, ainsi que les exploitations minières. Ils permettent de mieux comprendre le comportement des sédiments dans les bétons à partir de certaines analyses et traitements, et d’identifier les milieux agressifs convenables à l’utilisation des sédiments

Recycling of dredged sediments in self-consolidating concrete: mix design optimization and durability study

La demande en matériaux de construction a considérablement augmenté, dont la grande majorité est d’origine naturelle. Étant donné que ces matériaux ne sont pas renouvelables, il est essentiel de trouver des matériaux alternatifs. Les études récentes menées à l’IMT Lille Douai ont montré que les matériaux issus de dragage possèdent des propriétés pouzzolaniques intéressantes et peuvent être utilisées comme ajouts cimentaires alternatifs ou comme filler. Vu le volume important dragué annuellement, cette valorisation aura des impacts environnementaux et économiques très positifs. Les objectifs visés dans cette recherche portent sur : la valorisation des sédiments du Grand Port Maritime de Dunkerque (France) dans des bétons autoplaçants (BAPs) comme ajouts cimentaires ; la valorisation des sédiments fluviaux du Château de l’Abbaye (France) dans des mortiers comme ajouts cimentaires afin d’évaluer la mobilité et la stabilité des éléments traces métalliques ; la solidification des sables dragués des Iles-de-la-Madeleine (Québec) par liant hydraulique afin de produire des roches artificielles. Dans l'ensemble, les résultats de ce travail sur les sédiments mettent en exergue la contribution substantielle de ces matériaux à l’amélioration des performances des bétons et supportent leur emploi comme ajouts cimentaires. Ces résultats contribuent à réduire l’empreinte du CO2 dans le béton, ainsi que les exploitations minières. Ils permettent également de mieux comprendre le comportement des sédiments dans les bétons à partir de certaines analyses et traitements, et d’identifier les milieux agressifs convenables à l’utilisation des sédiments.Abstract: The demand for building materials has increased enormously, and the vast majority are of natural origin. Since these materials are not renewable, it is essential to find alternatives. Recent studies at the IMT Lille Douai have shown that dredged materials have interesting pozzolanic properties and can be used as alternative cement additions or as filler. Given the large volume dredged annually, this recovery will have very positive environmental and economic impacts. The objectives of this research relate to: (1) The recycling of sediments from Grand Port Maritime de Dunkerque (France) in self-consolidating concrete (SCCs) as Supplementary cementitious materials (SCMs); (2) The recycling of fluvial sediments of Château l’Abbaye (France) in mortars as SCMs in order to assess the mobility and stability of heavy metal elements; (3) The solidification of the dredged sands of Iles-de-la-Madeline (Quebec) by hydraulic binder in order to produce artificial rocks. Overall, the results of this work on sediments highlight the substantial contribution of these materials to improving the performance of concrete and support their use as SCMs. These results contribute to reducing the footprint of CO2 in concrete, as well as mining. Also, contributes to understanding the behavior of sediments in concrete from certain analyzes and treatment. Thus, identify aggressive environments suitable for the use of sediments

Mining Wastes as Road Construction Material: A Review

The mining industry manages large volumes of tailings, sludge, and residues that represent a huge environmental issue. This fact has prompted research into valorization of these wastes as alternative aggregates for concrete production, embankments, pavement material, etc. The use of mining wastes as a resource for construction presents two benefits: conserving natural resources and reducing the environmental impacts of mining. In the case of road construction, the use of mining wastes has not yet been developed on a large scale and there is a major lack of specific legislation. This gap is due to the variety of exploited rocks, the diversity of tailings, mine residues, or valuable by-products slated for valorization, and the environmental specifics. This paper presents a review on recycling mine wastes as road construction material, including waste rock and mine tailings. Those materials were mostly used in infrastructure where soils had initially poor geotechnical properties (low bearing capacity, frost susceptibility, swelling risk, etc.). Different mining wastes were used directly or stabilized by a hydraulic binder through geopolymerization or, in some cases, with bituminous treatment. Overall, the use of mine wastes for road construction will have a considerable environmental impact by reducing the volume of waste and offering sustainable raw materials

Artificial Rocks Made from Dredged Sands of the Magdalen Islands (Canada): Preliminary Study

The consumption of natural materials for construction purpose is increasing each year while the resources are limited. To reduce the environmental burden and efficiently optimize resources, the use of local and alternative resources as building materials is necessary. This solution is not always convenient, especially for the isolated places like islands, and the Magdalen Islands in Quebec are not an exception. Those islands are currently in a shortage of granular materials and must import them, which represents considerable economic and environmental costs. The general goal of this contribution is to take advantage of the local dredged sands, to be reused in civil engineering infrastructures. This study explores the feasibility of consolidated sandy sediments as an artificial rock, which may serve as mass elements for coastal protection against erosio

Feasibility of using marine sediments in SCC pastes as supplementary cementitious materials

AC

Durability of a cementitious matrix based on treated sediments

Significant volumes of sediment are annually dredged in France and all over the world and these materials may in fact be used beneficially as supplementary cementitious material. This paper studies the durability of a new cement matrix based on dredged marine sediment from the Dunkirk-Harbour (northern France). Several techniques are used to characterise the raw sediment, such as physical properties, chemical analyses and mineralogy. X-Ray Diffraction (XRD) analysis revealed quartz, calcite and kaolinite to be the main mineral phases. In order to eliminate organic matter and activate some of those minerals, the sediment is calcined at a temperature of 850 °C for 1 h. Moreover, four blended mortars were formulated by mixing a portland cement (CEM I 52,5 N) and the calcined sediment as a partial cement substitute (0%, 10%, 20% and 30%). Reference mortars, based on the blended cement, were then prepared. This re-use cannot be substantiated or efficient without a durability study. For this purpose, the following tests were conducted on those mortars: mercury porosity, accessible water porosity, chloride permeability, freezing and thawing, external sulphate attack, alkali aggregates reaction, compressive and bending strength tests. The results of most of those tests evidenced the fact that the mortar that contains 10% of the treated sediment is as efficient and durable as the reference mortar itself. This infers that the presence of these calcined sediments improves the general behaviour of mortar. Keywords: Sediment, Characterization, Calcination, Substitution, Durabilit

Valorization of Dredged Sediments in Self-Consolidating Concrete: Fresh, Hardened, and Microstructural Properties

Several studies have proven the use of dredged sediments as supplementary cementitious materials (SCMs), but limited information is available on the effect of such treated sediments on self-consolidating concrete performance. The main objective of this study was to evaluate the performance of self-consolidating concrete (SCC) fabricated with treated sediments. The sediments were thermally treated at 800 °C for 1 h. The packing density of the granular skeleton was optimized to reduce the paste content and produce SCC with relatively low binder content. Three different SCC mixtures were prepared with 0%, 10%, and 20% cement replaced with treated sediments by mass. Key fresh, physical, hardened, and microstructural properties of the investigated SCC mixtures subject to different curing regimes were evaluated. The test results showed that the optimized SCC mixtures exhibited adequate self-consolidation characteristics. The particle size and high chemical activity of the sediments led to pore refinement of micro-pores, increased density, improved microstructure, and reduced micro-cracks of the investigated SCC mixtures. Furthermore, the use of up to 20% of treated sediments resulted in a compressive strength of 66 ± 1 MPa at 91 days, which is comparable to that of the reference mixture made without any sediments. Leaching test results confirmed the ecological potential of producing SCCs based on sediments, which could be an interesting alternative of using local materials to reduce the high demand of cement, thus further reducing the CO2 footprint of concrete structures