Comparison of Two Sulfate-Bearing Soils Stabilized with Reactive Magnesia-Activated Ground Granulated Blast Furnace Slag: Swelling, Strength, and Mechanism

Sulfate-bearing soils, which causes many engineering problems, e.g., cracking, collapse, and pavement layer settlement, are often encountered in the construction of pavements. Ground granulated blast furnace slag (GGBS)-magnesia (MgO) has been regarded as an effective curing agent treatment sulfate-bearing soil containing gypsum. However, field soils usually include other forms sulfates, such sodium sulfate (Na2SO4) magnesium (MgSO4). Currently, few studies have investigated effect type on properties stabilized with GGBS-MgO. In this study, GGBS-MgO was used to treat Ca-sulfate-soil Mg-sulfate-soil. Swelling, unconfined compressive strength (UCS), X-ray diffraction (XRD), scanning electron microscopy (SEM) tests were employed investigate soils. The results showed that when suitable GGBS:MgO ratios achieved, swelling two types could be well suppressed. trend varied decrease opposite between UCS Mg-sulfate-soils much lower than Ca-sulfate-soils after stabilization irrespective or soaking stage. CSH significantly occurred Ca-sulfated treated by Ettringite not observed = 9:1 but 6:4. Compared Ca-sulfate-soils, MSH less formed GGBS-MgO, caused Mg-sulfate-soils. No ettringite Hence, contained had a significant so needs identified before soil’s stabilization.