Alberta Transportation's Experience with Cold In-place Recycling

摘要

Alberta Transportation constructed its first Cold In-place Recycling (CIR) project on Highway 761 near Rocky Mountain House in 2008. To date, the Department has used this technology on approximately 115 kilometres of roadway within nine separate paving contracts. The CIR specification used by Alberta Transportation calls for the use of a bituminous stabilizing additive and allow the Contractor to choose either an emulsified or foamed asphalt product. Of the nine projects completed to date, emulsified asphalt was used on eight and foamed asphalt on one. These projects also used a number of different contractors and CIR equipment trains. This paper discusses Alberta Transportation's project selection criteria; mix design procedures, and the quality control/quality assurance testing program. This paper also discusses the performance of the CIR projects to date, with an emphasis on the mitigation of transverse reflective cracking. Additionally, the performance of three comparator test sections, constructed in conjunction with the CIR projects, is also provided. Two of these projects included FDR comparators, while one included a Mill and Inlay comparator. Monitoring results to date show that CIR has not mitigated reflective cracking as much as originally anticipated. This paper also identifies potential changes to project design criteria and construction specifications that may improve reflective crack mitigation.