California Department of Transportation

Flexible Recycling (and Rehabilitation)

Typical flexible pavement recycling strategies used by Caltrans include Hot In-Place Recycling (HIPR), Cold In-Place Recycling (CIPR), and Full Depth Reclamation (FDR). FDR includes Pulverization and Cold Foam In-Place Recycling (CFIPR).

Although flexible pavement recycling strategies are capable of treating many different types of distress, not all rehabilitation projects are good candidates. Some strategies are better suited to treat certain distresses, and some projects are more suited to conventional rehabilitation methods. Review and assessment of pavement conditions, structural capacity, material properties, geometrics, traffic concerns, constructability, and cost effectiveness should be conducted as part of the project evaluation process.

Appropriate application of any rehabilitation strategy requires a comprehensive field review prior to design to evaluate the type, severity, and extent of the pavement distress (for more information, refer to the Pavement Evaluation Manual). The district Materials Engineer should be consulted during the initial project assessment. Other resources include as-built plans, the Photolog, the biannual Pavement Condition Report (PCR 3.2) for 2006-2007, and corresponding mapping available from Geographic Information Services (GIS).

The table below provides some general recycling and rehabilitation strategy selection criteria based on existing pavement distress:

Flexible Pavement Distress
Rehabilitation Strategies
HIPR CIPR Full Depth Reclamation (FDR): CFIPR or Pulverization
Thin HMA
>Thick HMA
Mill & Overlay
Combination Treatment
Structural Strength                
Alligator (Fatigue) Cracking                
Edge Cracking                
Slippage Cracking                
Shoulder Drop Off                
Reflective Cracking                
Transverse Cracking                
Longitudinal Cracking                
Block Cracking                
Ride Quality                


Skid Resistance                
More Appropriate
        Least Appropriate

Printable Flexible-Recycling-table.xls(MS-Excel, 17 KB)


Please forward any questions/comments/suggestions toShira Rajendra( Last updated 06/17/2011.