Foamed Asphalt

September 28, 2010

Foamed asphalt is the product of the injection of a predetermined amount of cold water into hot penetration-grade
asphalt in a series of individual expansion chambers in a base recycling machine — replacing costly asphalt emulsions
in base stabilization. The expanded asphalt has a resulting high surface area available for bonding with the aggregate,
leading to a stable road base using 100 percent of the existing in-place materials. Unlike asphalt emulsions, foamed
asphalt does not require a ""break"" period before it can be mixed.

And foamed asphalt technology is completely compatible with in-place recycling or crushing of degraded asphalt or gravel
road wearing courses. After grading and compaction, this surface can support traffic immediately, but often is soon
overlaid with a fresh, virgin wearing course. This in situ base recycling and stabilization is the most common application
of foamed asphalt throughout the world and North America.

ACP Articles on Foamed Asphalt

Foamed Asphalt Recycling In Zion National Park
Rocky Mountain Construction -- 10/09/2006

Last year's full-depth recycling of a scenic road in Utah's Zion National Park, incorporating foamed asphalt, shows how
roads in environmentally sensitive areas can be reconstructed economically and with minimal impact on the ecology.

New Technologies Promote Greater Use Of Asphalt
Construction Bulletin -- 10/06/2006

An innovative method of reusing asphalt has been the cold-in-place foamed asphalt recycling. Wirtgen Group, manufacturer
and marketer of a line of asphalt reclaiming and recycling equipment, asphalt and soil compactors, and U.S. sourced
asphalt pavers, tested their equipment using foamed asphalt recycling.

Foamed Asphalt New Option For Public Works Agencies
Midwest Contractor -- 05/09/2005

Foamed asphalt is a new cold-in-place road base recycling technology, which is offering public works agencies new options
for road base stabilization and recycling.

Public Works tries Foamed Asphalt
California Builder and Engineer -- 05/02/2005

The benefits of foamed asphalt-stabilized road bases are so compelling that the city of Los Angeles acquired its own
road base recycling machine and has been using it to recycle asphalt roads within its borders that are in need of

The State Of Paving
Western Builder -- 01/01/2004

Three warm asphalt processes are currently being studied by the National Center for Asphalt Technology — Wam Foam,
Zeolite and Sasobit. Wam Foam is a foamed asphalt process, and is a two-phase addition to the process.