The improvement of the geotechnical properties of low-plasticity clay (CL) using steel slag in Sulaimani City/Iraq

Abstract

ABSTRACT Expansive soils have the ability to swell and shrink with the variation in moisture content. Soil stabilisation is the process to improve the geotechnical properties of soils. The massive quantities of waste materials are resulting from modern industry methods create disposal hazards in addition to environmental problems. This study is carried out to evaluate the effect of steel slag (SS) as a by-product to improve the geotechnical properties of low-plasticity clay. A series of laboratory tests were conducted on natural and stabilised soils. SS was added by 0%, 2.5%, 5%, 10%, 15% and 20% to the soil. The conducted tests are consistency limits, specific gravity, hydrometer analysis, modified Proctor compaction, swelling pressure, swelling percent, unconfined compressive strength and California Bearing Ratio (soaked CBR). The results showed that the soil liquid limit, plasticity index, OMC, swelling pressure, and swelling percent were decreased when stabilised by steel slag. While the soil MDD, UCS and CBR were increased due to various percentages of steel slag. The steel slag was found to be successfully improving the geotechnical properties of expansive soils.