Development and evaluation of a cementless steel slag-blast furnace slag binder for stabilization of dredged soils with high natural water content

Abstract

Dredged soils with high water content, low shear strength, and poor compaction hinder reuse as construction materials. This study introduces a novel, cementless binder using an optimal mix of steel slag and blast furnace slag (OSB) to stabilize dredged soils at liquid limit. Soils mixed with 10–30% OSB binder and cured for up to 28 days were compared with compacted dredged soils (CDS) and rapid-hardening cement (RHC)-stabilized soils. OSB binder markedly improved strength, stiffness, and durability over CDS. After 14 days, unconfined compressive strength rose 100–300%, and shear wave velocity at vertical stress of 15.3 kPa matched CDS values at 57–113 kPa. Microstructural analyses showed C–S–H and C–A–H gels, enhancing interparticle bonding and lowering compressibility. OSB also delivered greater ductility and wetting-drying resilience than RHC, offering a sustainable, cost-effective option for low to moderate vertical stress uses, such as road subgrades.