Reclaimed Asphalt Pavements RAP Pete Coffman RAP Uses

Reclaimed Asphalt Pavements “RAP” Pete Coffman

RAP ◊ Uses ◊ Mix Methods ◊ Cost Savings ◊ Concerns ◊ Case Studies

Recycle ◊ 80% removed, recycled ◊ 74 Million Tons/year

What is RAP ◊ Aggregate and asphalt binders form a previous pavement structure. ◊ Produced by milling, breaking and grinding old pavements ◊ RAP is then blended with new (virgin) pavements

Uses ◊ New pavements ◊ Resurfacing existing roads ◊ Subbase materials ◊ Shoulder paving and widening

Uses ◊ Hot-in-Place ◊ Cold-in Place (emulsified) ◊ Portable or centralized hotmix plants

Mix Methods ◊ Marshall ◊ Hveem ◊ Superpave

Mix Methods ◊ Usually between 10 to 25 % uses in mixes. ◊ 50 % is Max recommended ◊ Florida uses 80% RAP in some pavements

Cost Savings ◊ Depends on Method of replacements ◊ Between 40 to 60% savings on asphalt cost. ◊ Can save contractors and road departments 10 to 25% on overall project costs.

Concerns ◊ Larger tenderness temp range than virgin HMA ◊ 93 o to 115 o (Virgin)- 93 o to 130 o (RAP) ◊ Segregation of stockpiles ◊ Densities- variations ◊ Compaction

Case Studies ◊ Tx. DOT-FM 2838 ◊ Cold-in-place resurface ◊ 4 in ◊ 90 to 110% of previous densities ◊ 30% cost savings

Case Studies ◊ Conn. Dot-SR 2 ◊ 15% RAP Mix ◊ Superpave ◊ Air content 3 to 6% @ Ndesign ◊ Air Content 2 to 5% @ Nmax ◊ Compaction Issues.

Conclusions ◊ Effective cost saver ◊ Reduces resource uses ◊ Works well on light to medium duty roads. ◊ Has issues with temp, compaction and road life

Questions ◊ Thanks for Listening