Five Year Performance Review of Cold In-place Recycling and Cold In-place Recycling with Expanded Asphalt Mix on Highway 7, Perth, Ontario

Cold in-place recycling (CIR) is an established pavement rehabilitation method that processes an existing hot mix asphalt (HMA) pavement, sizes it, mixes in additional asphalt cement, and lays it back down without off-site hauling and processing. The added asphalt cement is typically emulsified asphalt, a blend of asphalt cement and water which requires 14-day curing period before applying the new HMA surface. A recent development in CIR technology, termed Cold In-Place Recycled Expanded Asphalt Mix (CIREAM), is the use of expanded (foamed) asphalt, rather than emulsified asphalt to bind the mix. The advantage of CIREAM is that a new HMA surface can be applied after 3 days, and the process is less dependent on warm, dry weather which is required for the curing of the CIR. The Ministry of Transportation Ontario (MTO) constructed its first 5-km trial section of CIREAM on Highway 7, east of Perth in July 2003, adjacent to 7-km of CIR mix with emulsified asphalt. Annual performance review on both sections was carried out using Falling Weight Deflectometer (FWD) and Automatic Road Analyzer (ARAN). The five year performance review on CIR and CIREAM was analyzed using ANOVA, and the results indicate similar performance. CIREAM technology is a promising alternative to conventional CIR, and provides the same environmental benefits while extending the construction season and reducing the time required before application of the HMA surface. MTO will continue to monitor the long-term performance of this innovative rehabilitation technology.