Cold In-Place Recycling (CIR) for Bituminous Over Concrete (BOC) Status: CompleteProject Start Date: 09/09/2016 Summary: Cold in place recycling (CIR) has been used for about 20 years in Minnesota, but only on HMA over gravel roads. Iowa has reported success using CIR on bituminous over concrete (BOC) with less reflective cracking and less severe reflective cracking. The purpose of this project is to validate the Iowa practice. Along with the potential of a better service life is that cost of CIR is much less than new HMA, therefore on a project basis 20 percent to 30 percent price reduction, may be realized. The project would investigate HMA thicknesses, design and build a CIR with HMA on the top, then follow up each year measuring surface rating and ride each year for several years. Two new control sections should also be built and compared to the CIR section: a section with removing all the HMA and placing new HMA, and a M/OL section. The overall goal is to assess whether CIR works well over concrete. Final Deliverables: Related Materials: Related Research:
