Evaluation of Curing Effects on Cold In-Place Recycling (CIR)

Status: Complete
Report Date: 05/31/2022

Summary:

A cost-effective and environmentally friendly asphalt repaving method will now be more efficient. Cold in-place recycling (CIR) involves pulverizing the top layer of old pavement, mixing it with a stabilizing agent such as emulsified asphalt, and repaving and compacting the CIR, typically in a 3-4” thick lift. A final layer is added to seal and preserve the recycled pavement layer. This process minimizes the need for using new material and transporting materials to and from the construction site. The recycled asphalt layer, however, must sufficiently harden before the top layer can be placed. Local road engineers needed to know how long it will take for curing to occur. New research identifies the factors that impact CIR pavement curing, including the types of materials used, the outside temperature and the compacted density of the recycled asphalt. Researchers developed a Curing Prediction Model spreadsheet and guidance to reliably estimate the process time. This new knowledge will help to optimize construction schedules and minimize traffic disruptions.

Final Deliverables:

Evaluation of Curing Effects on Cold In-Place Recycling (Report #2022-11)
Curing Prediction Model Spreadsheet (Spreadsheet #2022-11S)
Increasing Cold In-Place Recycling Efficiency for Pavement Rehabilitation (Research Summary)

Related Materials:

Related Research:

Project Personnel:

Principal Investigator: Eshan Dave
Co-Principal Investigator: Shongtao Dai, Eyoab Zegeye, Jo Sias
Technical Liaison: Joel Ulring
Project Coordinator: Marcus Bekele
Panel Members:
    Chelsea Bennett - Materials & Road Research
    Chuck Grotte - Ottertail County
    Greg Ilkka - Steele County
    Michal Hanson - Mower County Public Works
    Terrence Beaudry - Materials & Road Research
    Tim Becker - Sibley County
    Timothy Andersen - Materials & Road Research
    Wayne Stevens - Brown County