Ten year follow-up study of airfoam-treated lightweight soil

Airfoam-treated lightweight soil is lightweight and provides for the early age development of shear strength and effective utilisation of dredged soils. This paper summarises a 10 year follow-up study of the lightweight soils that were placed as backfill at the seawall in Kobe Port Island and Tokyo International airport. These two sites are the early case examples of constructions undertaken in 1996 including the recovery project after the Kobe earthquake disaster and the offshore expansion project of the Tokyo International airport. Sampling and laboratory testing were carried out to investigate the physical and mechanical properties in order to compare the initial material condition. The depth profiles of the soil parameters such as bulk density, water content, pH, calcium content, shear strength, needle penetration resistance, compressive yield stress and compression index were examined. Consequently, it was confirmed that the physical and mechanical properties of the airfoam-treated lightweight soil satisfied their required performance criteria, indicating that the lightweight soil had sufficient durability for use as geomaterial for construction in coastal areas.