Study of Clayey Soils Stabilized with Ladle Furnace Slag as Alternative Binder for Use in Road Works

Abstract

Steelmaking industry generates a large volume of by-products that not always can be reintroduced into production processes, such as the steelmaking process itself or the production of cement. This is the case of ladle furnace slag (LFS), whose potential use is limited and usually ends up in landfill. This work investigates the feasibility of using LFS as binder for clayey soils stabilization in substitution of lime. The main parameters evaluated are plasticity index, California Bearing Ratio (CBR) and Unconfined Compressive Strength (UCS). The results show that the strength behavior of the mixtures is remarkable, obtaining increases in the CBR index between 8-14 times above unmodified clays. The mechanical performance base on UCS results show improvements of 85 % relative to natural soils three days after mixing. Moreover, if the curing time is up to 90 days, the UCS doubles or triples its value. Depending on the chemical composition of the soils, the performances of the mixtures are different, but in all cases the results are positive and encourage further research for the incorporation of ladle furnace slag as stabilizing agent.