Using Ground Granulated Blast Furnace Slag with Seawater as Soil Additives in Lime-Clay Stabilization

Abstract

Clayey soils are not favorable foundation for road pavement, due to their low bearing capacity and remarkable swelling potential because of water intrusion. Many previous studies demonstrated that the engineering quality of clayey soils can be improved significantly by physical and chemical stabilization techniques, thereby making clayey soils suitable for use in embankments. The present study examined the use of granulated blast furnace slag in powder-form, commercial lime and seawater to improve the engineering properties of a low-plastic clay soil. Clay soil samples were reconstituted by adding various percentages (by weight) of GGBFS, lime, and seawater at optimum water contents, based on compaction tests results. The specimens were cured for 1, 7, and 28 days. Unconfined compression and California bearing ratio (CBR) tests were conducted. The results indicated that the unconfined compression strength of the clay samples (stabilized with 5 % lime, 3.33 % GGBFS and cured for 28 days) was more than eight times the initial strength of the untreated samples, reaching 2500 kPa with seawater. Soaked CBR values also increased to more than ten times the initial value.

Use of slag (with cement) for improving the performance of expansive soil of road pavement subgrade

“…The CBR values of soaked samples also increased to more than ten times the reference values. From this study, Kavak et al [9] concluded that lime and slag could be used in combination as a useful additive to treat expansive soils, and mentioned that a certain amount of lime was needed to activate the slag.…”

“…Higgins [8] indicated that a commonly used stabilizing blend in Australia comprises of 85% slag and 15% hydrated lime effectively combats the expansion associated with the presence of sulfate in soil and equally combats extension associated with sulfides such as pyrites. Another study was performed by Kavak et al [9] on a low-plastic soil stabilized with lime and GGBFS using seawater for the hydration process (i.e., curing). The UCS and CBR tests were conducted on soil samples treated with 5% lime and 3.3% slag, and these mixtures were cured for 28 days.…”

“…The UCS and CBR tests were conducted on soil samples treated with 5% lime and 3.3% slag, and these mixtures were cured for 28 days. Kavak et al [9] concluded that the optimum results were obtained when the lime to slag ratio was 1.5:1 by weight. Using this ratio, the UCS value of the treated soil was increased to more than eight times of the initial UCS value of the untreated soil (i.e., reference value), reaching 2500 kPa.…”