Double Barrel Green System is an optional process that allows for the production of warm-mix asphalt without the addition of “costly commercial additives,” according to Astec. The process uses water, which does not smoke or smell, includes a high percentage of recycled product (RAP), and uses 14 percent less fuel. The use of water causes the liquid asphalt to foam and expand in volume. As it foams, the mixture coats the aggregate at a temperature about 50 degrees cooler than traditional hot mix, the company says. Other benefits include improved workability because of lower viscosity, and longer pavement life because of less oxidation ofthe mix and more uniformity of compaction.