Shrinkage Curve of Treated Sulfate-Bearing Soils with GGBS

Stabilizing sulfate-bearing subgrade soils by lime and cement has widely been known to cause a significant heave in those soils. One of the potential alternative stabilizers is slag cement, or commonly referred to as ground granulated blast-furnace slag (GGBS). Drought causes a volumetric shrinkage and substantial desiccation cracking in clay subgrade soils, which leads to tremendous distress in pavement layers. However, the literature review reveals that the desiccated shrinkage of GGBS-stabilized soils has been paid a little attention. This paper presents experimental results for a sulfate-rich compacted soil treated with GGBS in the laboratory. The experiments involve subjecting treated and untreated soil specimens to wetting until reaching the maximum swelling before being air-dried beyond the shrinkage limit. The soil shrinkage curve (SSC) is employed in this paper to interpret the shrinkage of treated soil. The SSC of the treated soil is compared with that of the untreated native soil to impart the performance of GGBS on mitigating each shrinkage zone of SSC. In general, the results demonstrated the high effectiveness of GGBS in alleviating the swelling-shrinkage behavior of the sulfate-rich soil. Stabilizing the soil by GGBS has diminished all shrinkage zones of SSC, but no considerable effect was observed on the shrinkage limit.