Experimental Research on Steel slag Stabilized Soil and its Application in Subgrade Engineering

An experimental program was carried out to explore the feasibility of steel slag replacing lime used in the pavement of highway subgrade. The compaction test, the bearing ratio test, the unconfined compressive strength test, the splitting tensile strength test and the water stability test were carried out for different mixture ratio. And field test was also carried out to verify the application of steel slag. The test results showed that the immersion bearing ratio of steel slag stabilized soil increased with the increase of compaction degree and content of steel slag. The CBR value of Steel slag stabilized soil with 8–15% slag content was basically equivalent to that of 4% lime soil. The failure strain of 8% or 15% steel slag soil is larger than that of lime soil or cement soil. The strength of lime soil, cement soil and steel slag stabilized increased monotonously with the increase of curing age, but the growth rate of lime soil was significantly higher than that of steel slag stabilized soil. The 7d unconfined compressive strength of 8% steel slag stabilized soil reached 0.41 MPa, which met the requirements of highway subgrade materials. The initial moisture content had a great influence on the steel slag stabilized soil, and it was necessary to strictly control the moisture content for subgrade constructing. The content of steel slag in the steel slag stabilized soil was measured by EDTA method which is effective. The deflection value of 8% steel slag stabilized soil was 130.8 (10⁻² mm), which can meet the requirements of the design specification [232.9(10⁻² mm)].