Study on the treatment of dredged material as backfill material for construction projects

Abstract

Dredged sediment typically exhibits high moisture content, plasticity, and significant swelling potential, posing challenges in construction and compromising stability during land leveling and backfilling. To enhance its physico-mechanical properties and volumetric stability, solidification additives such as cement are widely employed. Cement acts as a binding agent, initiating chemical reactions with water and minerals in the sludge, thereby reducing plasticity and increasing rigidity. Furthermore, the incorporation of supplementary additives (e.g., fly ash or blast furnace slag) with cement enhances the solidification efficiency of dredged sediment and reduces material costs. This approach not only enhances material quality but also promotes the reuse of dredged sludge in sustainable construction applications. In this study, a treatment method combining cement and steel slag is proposed to stabilize dredged sediment for construction projects. When incorporating 2% cement and 10% steel slag (by weight of the original sediment), the composite’s mechanical properties fully comply with technical specifications, demonstrating its viability as backfill material in construction.