Cold In Place Recycling Troubleshooting

Observable Crack Sealant or Paving Fabric in the Mat

•  Remove visible oversized material prior to compacting

Appearance of Uncoated Material in RAP

• If consistent, adjust recycling agent and water to compensate
•  If inconsistent, confirm thickness of existing HMA layer. Make cutting depth slightly shallower if will not affect the pavement structure

Mix Segregation

• If by mechanical separation, check process flow and screed transfer augers
• If inadequate asphalt coating of the aggregate due to inadequate water content or recycling agent, adjust application rates

Varying Dry and Wet Spots in RAP

• Check water and/or recycling agent application systems 
• Adjust application rates if caused by RAP gradation changes

Oversize or Undersized RAP in the Mix

• Check screening/crushing unit, breaker bar or speed of train 
• Check milling machine for worn or broken teeth and replace

Flushing of Asphalt at Surface

• If excessive mix water, reduce the target water content in the mix 
• If excessive recycling agent, reduce asphalt content 
• If inadequate mixing of materials, check mixing chamber for signs of wear/build up 

Mat Stays Spongy and/or Will Not Densify 

• Reestablish control strip and/or density rolling pattern 
• If steel wheel rollers are sealing the surface and causing moisture retention, use a heavy pneumatic tire roller for the breakdown and compaction rolling 
• If excess moisture is in the mix, revise recycling agent and water as necessary

Dimpling Due to Parked Vehicles or Equipment 

• Tack and fill with asphalt mixture (cold mix, recycled mix, WMA, or HMA) prior to surface course

Permanent Deformation

• Within Wheel Path Areas Due to Secondary Compaction by Traffic: If pavement temperatures permit, apply secondary compaction. Tack and fill with asphalt mixture (cold mix, recycled mix, WMA, or HMA) or micro surfacing in the low areas or cold mill to provide a smooth surface
• Permanent Deformation and Shoving Due to Unstable Mix: Investigate pavement structure in conjunction with mix design lab. Depending on investigation, remove tack and replace affected areas with asphalt mixture (cold mix, recycled mix, WMA, or HMA) or re-recycle supplementing with uncoated coarse aggregate, additives and/or recycling agent as necessary

Raveling, Scuffing or Tearing

• Isolated Areas of Minor Raveling or Scuffing: Sweep and monitor. Determine if fog sealing or re-fog sealing is necessary to protect
• Isolated Areas of Major Raveling, Scuffing or Tearing: Maintain better traffic restrictions in areas that are not cured. Sweep and monitor. Determine if fog sealing or re-fog sealing is necessary to protect. Tack and fill or remove tack and replace deep damaged areas with asphalt mixture (cold mix, recycled mix, WMA, or HMA) prior to surface course
• Large Scale Areas of Raveling, Scuffing or Tearing in Straight Traffic Areas: Re-recycle or remove tack and replace with asphalt mixture (cold mix, recycled mix, WMA, or HMA)

High Spots out of Surface Tolerance

•  Correct humps exceeding tolerance by reworking, rerolling, trimming or milling and fog seal as necessary