Field and Laboratory Investigation of Highly Organic Clay Stabilized with Portland Cement

This article presents mass stabilization studies performed on very soft organic clay, with very high water content, very low pH value, and high clay activity, treated with high early strength dry portland cement. The specimens were prepared in a laboratory with differing cement contents and subjected to unconfined compression tests under different preloading conditions and curing times. Undisturbed samples of the mass stabilized soil were collected in situ and subjected to unconfined compression tests. The results showed that the preloading during the curing period and the amount of cement directly influenced the strength and the secant modulus of the organic clay stabilized in the laboratory, reducing the porosity of the specific blends studied. The strength measured in the laboratory specimens was about twice as high as the strength measured in the field specimens, which, in turn, was about five times higher than the strength of unstabilized soil. Finally, it can be concluded that for the highly organic clay and cement blend conditions studied in this paper, the porosity controls the mechanical properties of the blends.