Foamed asphalt is sometimes used during the asphalt recycling process, and sometimes on low volume roads. Some of the foamed asphalt manufacturers would be willing to provide you with literature concerning the benefits of the product. I should tell you that it holds a very small percentage of the market share in the Rocky Mountain region of the USA, and is therefore a somewhat expensive, speciality product.
Here is a link to a website with lots of reference materials -- I haven't read them all, sorry.
http://asphalt.csir.co.za/FArefs/
Best Regards,
Steve Mueller
Denver, CO, USA
