Bioashes and Steel Slag as Alternative Binders in Ground Improvement of Quick Clays

Using alternative binders to traditional lime-cement mixtures in deep soil mixing is studied with the objective of reducing the carbon footprint of this ground improvement technique. Two by-products, bioashes and steel slag, combined with cement, were mixed with quick clay to investigate the strength and deformation properties of the stabilized material, as well as the leaching of contaminants for its environmental characterization. Bioashes and steel slag are residual products from the wood and steel industry, respectively. Results showed that after combining bioashes or steel slag with cement into quick clay, the strength and stiffness of the original material increased. The by-products were below the leaching limits for inert landfills following the European regulation, when tested both individually and combined with cement and quick clay. These findings reveal that bioashes and steel slag may provide sustainable alternatives to lime or cement in soil stabilization of quick clays.