Research studies and road applications utilizing the Foamix process during the past four years were reviewed by a five-member panel. During that period, usage of foamed asphalt has expanded from two to 16 countries worldwide. A small stream of water injected into hot asphalt cement results in a large-volume stream of foamed asphalt for easy mixing with cold wet aggregates. Conventional equipment is used for mixing and laydown. A wide range of aggregates, including, in particular, local marginal-quality materials, can be used.

Outside Australia and New Zealand, trial sections were constructed during 1977 in South Africa and Colorado, later in Botswana, France, and Germany, and most recently in Michigan. A full-depth, 9-km (5.6 mile) road was completed in North Dakota during the fall of 1979. Most use is for base sections ultimately given surface protection. One trial was an in situ application to recycled material. Foamixes have performed as unsealed liners for sewage lagoons and as stockpiled patch material.

Reviews of research studies in Colorado, California, and Texas provide a broad range of data from a variety of aggregates and test procedures. A counteragent has been developed to negate the effect of antifoam additives present in some asphalts.