Cold In-Place Recycling of hot mix asphalt pavement is an effective pavement rehabilitation strategy with many social, economic and environmental benefits. These include a short construction period, reuse of existing materials, reduction in transportation of materials, reduced greenhouse gas emissions and fuel consumption, and the fact that it is a cost effective treatment.
Ontario has been using CIR with emulsified asphalt binder since 1990. CIR is considered to be an established pavement rehabilitation method. The CIR process mills up the existing asphalt pavement, sizes it, mixes in emulsified asphalt, lays the mix back down, and compacts the material without off-site hauling and processing. In 2003, a new development in CIR technology was introduced, using expanded (foamed) asphalt instead of an emulsion to bind the mix. This combination of CIR and expanded asphalt technologies was introduced as Cold In-Place Recycled Expanded Asphalt Mix (CIREAM).
The Ministry of Transportation Ontario (MTO) constructed its first trial section of CIREAM on Highway 7, east of Perth in July 2003. Under the same contract, a 5-km trial section of CIREAM was constructed adjacent to 7-km of conventional CIR mix. The performance of these two sections has been monitored over the past 10 years, using the Ministry’s Automated Road Analyzer (ARAN). The results indicate that CIREAM is performing in a similar fashion to conventional CIR. Both treatments are providing excellent long term performance and have been shown to significantly reduce or eliminate reflective cracking.
