Suitability Assessment of Using Lime Sludge for Subgrade Soil Stabilization

Abstract

Although several studies have been conducted regarding the use of lime sludge (LS) in engineering and agricultural applications, its use for stabilizing subgrade soils has not been fully investigated. In this study, an effort was made to evaluate the suitability of using LS alone or in combination with traditional stabilizers [fly ash and portland cement (PC)] to stabilize a frost-susceptible loess soil (LOE). A series of unconfined compression (UC), pH, and freeze-thaw (F-T) tests, as well as scanning electron microscopy (SEM), were performed for the evaluation. Test results indicated that using LS alone effectively improved the unconfined compressive strength (UCS) of the soil. In addition, using LS in combination with fly ash yielded further improvements in the UCS of the soil compared with using only fly ash for stabilization. Alternatively, using LS in combination with PC improved the UCS of the soil to a lesser extent than using PC alone for stabilization. In all the cases, the presence of LS in the soil matrix reduced the F-T durability.