Although CIR can address most types of pavement distresses, cracked pavements which are structurally sound and have well-drained bases are the best candidates. The CIR process disrupts existing crack patterns and produces a crack free layer for the new surface course such as an asphalt overlay or an asphalt surface treatment. For CIR to be effective in mitigating cracking, as much of the existing asphalt pavement layer should be treated as possible. The greater depth of the crack that is removed the less impact the remaining crack will have on pavement performance. Typically, 70 percent of the existing asphalt pavement thickness needs to be treated in order to fully mitigate reflection cracking. A CIR mat and subsequent overlay provides better reflective crack resistance to that of a mill and fill application.
If the pavement is experiencing alligator cracking, distortion, or major structural / base failures, then it is not a good candidate for CIR. If the distress is localized, then base repairs can be performed prior to CIR, otherwise, consider FDR or CCPR with base stabilization.
CIR usually “fluffs” 10% - 20%, unless the existing road has excessive depressions/rutting, or if the new slope is greater than the existing slope.
Here is an example of the limits of crossfall correction:
Traffic volume should not be a consideration provided that pavement structural design is conducted and the recycled material is designed to have sufficient early and long term strength.
Long, steep grades and sharp radius turns can be difficult to process with some equipment setups. In urban locations, locate utilities and slowly pilot traffic around the recycling train to keep everyone safe.
There are no climate restrictions for cold in-place recycling. CIR has been used successfully in all four climate zones, wet freeze, dry freeze, wet no freeze and dry no freeze. However, there are weather restrictions during construction. See Weather Requirements for more information.