Ladle Furnace Slag in the Construction of Embankments: Expansive Behavior

This paper examines the use of ladle furnace steelmaking slag (LFS) as a material for the construction of embankments in civil works. It reports the chemical, mineralogical, and geotechnical properties of two soils, two LFS, and various mixtures thereof, in addition to their volumetric stability. The findings show that lengthy periods of time are required to achieve the potential expansion of LFS because of the hydration of certain aluminates and calcium oxide in addition to the slow hydrocarbonation reactions of magnesium oxide. The expansion test on the soil-LFS mixtures revealed slight swelling, attributable to the pozzolanic reactions of clay minerals with portlandite and brucite in addition to accommodation within the soil-slag pore structure. The cation exchange capacity of clay minerals affects the interaction between soil and LFS; minerals such as montmorillonite, with a high cation exchange capacity, improve the California bearing ratio and reduce the potential expansion. Not all soils are suitable for improvement with LFS because of the mineral compounds of their clay fraction.