Prétraitement et traitement des sédiments de dragage en vue d’une valorisation dans le génie civil

This work is part of a broader research program in the Civil and Environmental Engineering Department of the École des Mines de Douai on the reuse of industrial by-products in civil engineering. The thesis focuses on two materials: fine dredged sediments and steel slags, considered as co-products of metallurgical industries. It develops a five-chapter experimental methodology for the pretreatment, treatment, and valorization of these materials, particularly for road construction. The first chapter presents a literature review on dredged sediments and steel slags, covering their composition, current management practices, and the relevant legislative framework. The second chapter provides a general characterization of the materials, analyzing their physical, mechanical, mineralogical, and environmental (pollution) properties. The third chapter examines the natural drying of two fine dredged sediments, studying the effects of evaporation and drainage on water content reduction as a function of physical properties, composition, and initial moisture content. The fourth chapter develops road material formulations based on dredged sediments and steel slag, including lime and cement treatments of sediments and application of a packing density model. The final chapter proposes the structural design of a pavement base course composed of these formulations, using the French pavement design method to assess the suitability of these industrial co-products for road engineering applications in terms of allowable stresses and strains.