Asphalt recycling is not a new concept. Cold recycling/rehabilitation of roadways with asphalt binders dates to the early 1900’s. Two events of the 1970’s rekindled interest in asphalt recycling and the development of Cold In-place Recycling (CIR). The two events were the petroleum crisis of the early 1970’s and the development and introduction of large scale cold planing equipment with easily replaceable tungsten carbide milling teeth. Early champions like Oregon, New Mexico, Kansas, and Ontario found they could use emulisified asphalt or foamed asphalt to recycle their existing asphalt roads into a good-performing base course that slowed the return of cracking. Early variants were grader laid, but pavers soon became the norm for more controlled placement.
As agencies have monitored CIR jobs from 1979 through today, CIR delivers cost and emissions savings while delaying or eliminating reflective cracking and other distresses. Many states and provinces have large annual programs, and CIR is used worldwide to rehabilitate roads with less material and less disruption to the travelling public.