Application Sequence
- Clean roadway of objectionable materials and perform any necessary patching or pre-milling
- Crush and screen the RAP, if required
- Feed RAP, recycling agent and any additives into the cold mix plant
- Transfer the recycled mix to the site in haul trucks
- Tack the existing surface prior to placement of the CCPR mix
- The recycled mix is either placed in a windrow on the pavement and placed into a paver using a windrow elevator or placed directly into the paver hopper
- The mat is compacted by heavy pneumatic and double drum vibratory rollers
- A fog seal and blotter sand are applied if raveling is a concern
- The road is opened to traffic soon after compaction is achieved (within hours)
- The recycled mixture is allowed to cure for a minimum of three days
- With emulsified asphalt recycling agent, consider rerolling when the pavement temperature exceeds 80 F (27 C) to reduce air voids.
- A surface course is applied after the recycled mixture has cured
Application Guidelines
CONTROL STRIP:
- If required, a control strip should be placed in conditions similar to those that are expected to occur during construction.
Recycling Agent and Additives:
- Added at the central plant
- Verify application rate using meter on plant
MIXTURE:
- Particles should look evenly coated
- Particle size should meet specification requirements (especially top size)
- No blobs or stringers of undispersed recycling agent
- Not segregation in windrow or in paver
FRESH MAT:
- Uniform look with no major segregation, streaks or fat spots
- Placed to consistent depth
- The mat will look coarser than a typical hot mix mat. This is normal, as the CCPR mix has higher voids and larger aggregate max size than dense graded asphalt. With rolling traffic the surface of the CCPR mix will knead together and look tighter.
- At first, the mat may look brown. Some emulsified asphalts have a brownish color before the emulsion breaks and turns black. This happens soon after placing.
- Check for slope / crossfall directly behind the paver
COMPACTION:
- Established rolling pattern via control strip to achieve target density
- Ensure roller drums are clean and not covered with picked up material
- Roller skirts are not needed as the mix temperature is close to ambient
- Rollers should not be stopped on the fresh mat
- For foamed asphalt mixes, keep the water content at optimum moisture content to aid compaction
- Check compaction with nuclear gauge
- Check slope with straightedge / smart level after final roller
RETURN TO TRAFFIC:
- Control traffic to keep stopped traffic off the fresh mat
- Traffic should be piloted slowly on the fresh mat to prevent ravelling
- If fog seal is used to prevent raveling, apply sand blotter and/or wait for the fog seal to cure before allowing traffic
- Watch for early signs of rutting, ravelling, or other distresses, and notify the contractor immediately if a problem persists
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