The production of foamed asphalt starts with recycled pavement that is milled or crushed and is sized to a very specific gradation requirement. The process continues when a small amount of water is blended with hot liquid asphalt causing it to foam, not unlike a freshly poured soda…and making it well suited for mixing with the unheated bitumen aggregates. The recycled aggregate is then blended with foam and a small amount of Portland cement. The blending is computer controlled in a specialized plant designed specifically for producing foam asphalt. The process involves very little energy consumption and produces no greenhouse emissions.
Green Mix is not hot to the touch, so no personal protective gear is necessary. It is trucked to the jobsite and placed with traditional paving equipment so no special equipment is necessary. Green Mix stays workable for many hours making it versatile for a wide range of projects. On extremely hot days, workers appreciate not having to work with material that is over 250 degrees Fahrenheit.
After your pavement is fully constructed, it will look and perform like a pavement that is made with 100% traditional hot mix asphalt. The difference is that your pavement will be less expensive and will be much more environmentally friendly than a 100% hot mix pavement.
Many studies have been done to test the strength and stability of foamed asphalt. Some of these studies are contained on this website. Green Mix is the newest generation of foamed asphalt and our private study indicates it is equal to or better than other foam asphalts.
The original bitumen foaming process was a process that was patented by Mobil Oil in the 1950's. The use of the technology then was restricted for many years by the patent protection. The patent rights were brought by a German company Wirtgen, and they sought to make equipment that would take advantage of the foamed process.
Secondly, there has long been a lack of standardized mix design procedures meaning that more well documented and familiar products like hot mix have been preferred. Until very recently, no one would come forward to spend significant dollars to commission studies on foaming asphalt. Finally, more recently, the hyper escalation in the world price of petroleum has demanded closer attention to products that use much less petroleum than traditional products such as hot mix asphalt.