Abstract: Foamed mixture lightweight soil using river sludge(FMLSS) as a new engineering material of light weight and high strength is applied widely in engineering. By using physical and mechanical test methods on density, strength and consolidation, the physical and mechanical characteristics of FMLSS are analyzed in the presence of different cement contents, air foam contents, water contents and curing ages. Results show that the density, strength and deformation of FMLSS are mainly affected by cement content, air foam content and water content, and the influence of interaction among different factors cannot be ignored. In addition, the strength and stiffness of FMLSS are also affected by curing age, with which displaying a good hyperbolic relationship. Under external load, FMLSS shows good resistance to deformation. The study indicates that FMLSS has good engineering applicability and application prospect.

Key words: foamed mixture lightweight soil using river sludge, physical and mechanical characteristics, cement content, air foam content, curing age, interactive function