EquipmentWorld.com | August 2015
51
J
ust like the swelling froth of expanded liquid
asphalt in a foamed asphalt application, use
of foamed asphalt in warm mixes is grow-
ing exponentially, and its use for full-depth
recycling and base stabilization of roads is
increasing as well.
Warm mix asphalt (WMA) production in the
United States has exploded in recent years, from
19.2 million tons in 2009 to 86.7 million tons in 2012,
an increase of more than 400 percent in only three
years, according to the National Asphalt Pavement
Association. Since mechanical foaming units were
used in 88 percent of all WMA produced in 2012,
it's clear the use of foamed asphalt is following the
same steep growth trajectory.
To help everyone understand the new WMA envi-
ronment of foamed asphalt, the National Cooperative
Highway Research Program released a new report
earlier this year on test methods, performance mea-
surements and mix designs. (A copy of the report
can be downloaded by doing an Internet search for
"NCHRP 807.")
Photo:
Wirtgen
America
Foam stabilization is not just for mobile recy-
clers; adjacent to Virginia's I-81, Wirtgen KMA
220 portable cold mix plant foam-recycles
cold millings from the Interstate for immedi-
ate placement as a fl exible base course.
