Mechanical Properties of the Unsaturated Foam Composite Light-Weight Soil

Light-weight soil is mainly used effectively as recycling technology of the construction surplus soil in Japan. Foam composite light-weight soil proposed in this study is a mixture of clay, cement, and foam. As a porous material, the wet unit weight of the foam composite light-weight soil is decreased by the usage of foam from 7 kN/m³ to 13 kN/m³ compared to a normal soil which is around 18 kN/m³. In this study the mechanical properties of unsaturated foam composite light-weight soil are investigated. Laboratory test with initial suction, isotropic consolidation, consolidated drained and constant water triaxial compression tests are carried out on unsaturated foam composite light-weight soil samples. From the study carried out, it is learned that initial suction do not exist, and collapse phenomena do not occur when the isotropic stress is below consolidated yield stress for this kinds of soil. The authors also found that the stress path and the failure criterion of this peculiar unsaturated foam composite light-weight soil are best described with an independent effective strength formula.