HANDLING RAP IN AN HMA FACILITY

This final installment of a three-part series on the use of reclaimed asphalt pavement (RAP) in hot-mix asphalt (HMA) addresses the handling of RAP in the HMA facility and placement and performance issues. Use of RAP is now a well-established, routine production practice in the HMA industry. With the growth of cold milling of HMA pavements as a rehabilitation strategy, production of RAP is estimated at 45 million tons (41 billion kg) per year. In the HMA facility, the RAP must be dried and heated prior to mixing into the HMA. No special techniques or equipment are required for laydown and compaction when using recycled mixes. However, recycled mixes are frequently placed at slightly cooler temperatures than virgin mixes in an effort to reduce the negative impact of superheated temperatures on the facility equipment. No significant differences between recycled and control pavement sections in pavement performance condition, structural numbers, or recovered asphalt cement properties have been reported.