Effect of Changes in Chemical Properties on Long-term Strength of Compacted Soil Stabilized with Low Additive rate of Cement under Soaked Curing

Abstract

To investigate the effect of changes in chemical properties on the long-term strength of the compacted soil with stabilization by small amount of cement, specimens were cured under sealed and soaked conditions in laboratory. Unconfined compression tests and chemical analyses (XRF and XRD) were conducted periodically until 2 years. At each period of curing, the unconfined compressive strengths of the specimens soaked were lower than the strengths of the specimens sealed. The strengths of the specimens soaked for 2 years were not decreased significantly but higher than the strength of the specimens sealed at the short period such as 7 days. The difference between soaked and sealed samples for 2 years was shown by XRF and XRD in terms of the distribution of Ca ion or the existence of ettringite on the cross-section of the specimens. It was inferred that the difference in strength of the specimens soaked from those sealed at each period of curing was attributed to the dissipation of hydrates such as ettringite from the surface of specimen. On the other hand, strengths of the specimens soaked for 2 years were kept higher levels than those sealed at initial curing periods, due possibly to the existence of hydrates on the specimens soaked even after 2 years.