Abstract: Frothing techniques with mixed polyurethane materials have been widely used in the field of civil engineering. Polyurethane has many properties, such as frothing quickly, stronger viscidity and better elasticity. Frothed and vulcanized polyurethane, combined with other hard granules, can form a new kind of backfill materials who have higher initial strength. Recognizing these properties, the frothing technique of polyurethane materials can be applied in consolidation and backfill of concrete and roadbed structure. In this paper, on the base of the experimental research on the materials’ properties, a test simulating an actual consolidation of subsoil was carried out. The stable backfill substance was formed quickly by frothing of polyurethane in the pore space of gravels, and used as base of pavement. The surface of pavement can be made from gravels and some certain polyurethane. It took 2 hours to backfill the base and make the surface. Then, both static and impact loads were applied. The result of the test indicated that the mechanical properties of surface and base made up of polyurethane composite materials can satisfy certain standards and specifications.