Full Depth Recycling - No Stabilizer (FDR-N)
Full Depth Recycling - No Stabilizer (FDR-N) is an on-grade method of pavement rehabilitation that consists of pulverizing the existing asphalt concrete pavement and a portion of the underlying granular base to a maximum depth of 12 inches, grading and compacting the recycled mixture, and overlaying the recycled surface with a new layer of hot mix asphalt (HMA). Other materials including aggregate base, lime, Portland cement, kiln dust, or fly ash may be added prior to mixing as needed.
Figure 1. Full Depth Recycling - No Stabilizer
Application
FDR-N is best suited for moderate to low volume roadways. During construction, vehicles must traverse an untreated surface, so the project site requires 24-hour pilot car traffic control. FDR-N can treat most pavement distresses that are not caused by subgrade or drainage problems, but it is most cost effective on surfaces requiring digouts of 20% or more by paving area. The upper portion of the pavement structure is completely reworked. Distresses and surface irregularities treatable using pulverization include:
- Raveling
- Corrugations
- Slippage
- Poor ride quality
- Potholes
- Bleeding
- Shoving
- Delamination
- Rutting
- Cracking
Special Considerations
The following conditions may need to be addressed prior to FDR-NS activities:
- High traffic volumes
- Treated bases
- Numerous shallow utilities
- Poor drainage
Implementation
Specifications for FDR-N can be found in the 2022 Standard Specifications Section 30-2 Full Depth Recycling - No Stabilizer.
Please forward any questions/comments/suggestions to HQ Office of Asphalt Pavements at CIR@dot.ca.gov.