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

Abstract

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.