An Experimental Study on Stabilization of Expansive Soil Using Steel Slag and Crushed Limestone

Abstract

This study is carried out to evaluate the effect of steel slag (SS) as a by-product and crushed limestone (CRL) as additives on the geotechnical properties of expansive soil. A series of laboratory tests were conducted on natural and stabilized soils. Both of SS and CRL were 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, and California Bearing Ratio (Soaked CBR). The results showed that the values of liquid limit, plasticity index, optimum moisture content, were decreased. Also, with the addition of the mixture of “10% SS with 10% CRL” which cured for 28 days, the values of swelling pressure and swelling percent were reduced by 69.8% and 84.3% respectively. Whereas, the values of maximum dry density (MDD) increased from 17.66 kN/m3 to 18.79 kN/m3 and from 17.66 kN/m3 to 18.25 kN/m3 with the addition of 20%SS and 15% CRL respectively. Also, with the addition of the mixture of 10% SS+10% CRL and 20% SS+15% CRL individually, the values of CBR increased from 3.4% to 26.7% and from 3.4% to 39.5% respectively. The steel slag and crushed limestone were found to be successfully improving the geotechnical properties of expansive soil.