Pavement

Foaming of bitumen permits the bitumen to be evenly distributed throughout a soil or a granular material. It is critical for the bitumen to remain as viable foam for a period to enable it to be successfully blended into the host material.

The foaming characteristics of bitumen are defined by the expansion ratio and half-life of the bituminous foam. The bituminous foam is produced by introducing a small amount of water into hot bitumen.

The aim is to determine the percentage of water and foaming agent (if necessary) to produce the best foam characteristics for a particular bitumen. The amount of water will be a compromise between having as high as possible an expansion ratio with the longest half-life.

This method is an adaptation of the method described in Wirtgen Cold Recycling Technology.