Microscopic evaluation of 1-D compression for air-form treated lightweight geo-material

A lightweight geo-material (LGM) for port construction has been developed as a value-added material, which is not only a means of recycling dredged soil but also offers additional functions such as improvement of the earthquake-proof capacity by decreasing the lateral earth pressure on a seawall and prevention of the differential settlement by decreasing the overburden stress on an underground structure. The deformation characteristics of LGM due to its own weight and the weight of superimposed structures were studied using scanning electron microscopes and colour laser 3-D profile microscopes. Preparation of the air-foam treated LGM is described. The void ratio minus log compression pressure relationship of the LGM showed a reversed S-shaped curve which is similar to that of a natural clay deposit with a well-developed structure. This relationship could be properly evaluated from a microscopic point of view. The one-dimensional compressibility of the LGM could be qualitatively and quantitatively evaluated from a microscopic point of view, in particular the distortion of the air-foam bubbles. It is considered possible to match up the cement hydration with the aging effect and the air-formed skeletal structure with the soil structure, providing a model system for the skeletal structure of a natural clay deposit. For the covering abstract see ITRD E128041.