Reclaimed Asphalt Pavements “RAP” Pete Coffman

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

Recycle ◊80% removed, recycled ◊74 Million Tons/year ◊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 ◊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 ◊New pavements ◊Resurfacing existing roads ◊Subbase materials ◊Shoulder paving and widening

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

Mix Methods ◊Marshall ◊Hveem ◊Superpave ◊Marshall ◊Hveem ◊Superpave

Mix Methods ◊Usually between 10 to 25 % uses in mixes. ◊50 % is Max recommended ◊Florida uses 80% RAP in some pavements ◊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. ◊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 ◊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 ◊TxDOT-FM 2838 ◊Cold-in-place resurface ◊4 in ◊90 to 110% of previous densities ◊30% cost savings ◊TxDOT-FM 2838 ◊Cold-in-place resurface ◊4 in ◊90 to 110% of previous densities ◊30% cost savings

Case Studies ◊ConnDot-SR 2 ◊15% RAP Mix ◊Superpave ◊Air content 3 to N design ◊Air Content 2 to N max ◊Compaction Issues. ◊ConnDot-SR 2 ◊15% RAP Mix ◊Superpave ◊Air content 3 to N design ◊Air Content 2 to N max ◊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 ◊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