Why Recycle?

There are several obvious advantages to recycling, and some that are not so obvious:

  • An aged, distressed pavement is replaced with a safe, smooth, durable surface.
  • Recycling reuses the existing aggregate and asphalt, cutting down on new raw material costs. When done in-place, hauling costs are reduced.
  • Cracked pavement is removed, preventing future reflective cracking.
  • Deformations such as potholes, ruts, bumps and shoved pavement are leveled.
  • Drainage problems can be fixed.
  • Crowns can be re-established.
  • Clearances under bridges and curb height can be restored.
  • With the proper choice of materials, aged asphalt can be rejuvenated, and poor aggregate gradations can be corrected.
  • Polymers can be added to improve flexibility, adhesion, strength and resistance to temperature extremes.
  • The recycled pavement can be higher quality than the original.
  • In some locations, the large piles of material milled off of old pavements are becoming a problem. This RAP (reclaimed asphalt pavement) can be used as a valuable raw material instead of being considered as waste.
  • In-Place recycling minimizes the time a lane is closed for re-construction.
  • The savings in costs of new materials can be applied to increasing the improvements in our streets and highways.
  • There is excellent public acceptance of recycled materials.
  • The recycled pavement can, itself, be recycled when its time has come.


When to Recycle?



Almost any distressed asphalt pavement can be recycled, but the following are cases where recycling can solve existing problems most cost-effectively over the long term.
  • A pavement has reached the end of its design life and exhibits classic alligatored fatigue cracking.
  • There are drainage problems.
  • There are problems with the underlying pavement structure.
  • A newly laid pavement is rutting and shoving.
  • A pavement is marred with thermal cracks that have raveled to form potholes.
  • There are low clearances under bridges and overpasses.
  • Curbs and gutters are no longer protecting lanes, sidewalks and adjacent properties from storm water.


Where to Recycle?



There have been successful recycling projects on rural roads, busy city intersections and Interstate highways. As in any paving project, the design (including material selection and construction method) should be based on the particular situation.

Several very effective techniques have led recycling to become an accepted part of the asphalt paving industry. The key to a successful project is an analysis of the existing conditions and selection of the best available materials and method. The existing asphalt concrete should be tested, and the pavement structure and causes for distress understood. We don't want to make the same mistakes which caused premature distresses --such as using stripping sensitive materials or sub-base problems. It is also important to draw on locally available experience, materials and equipment.

The aged, fatigued pavement will need a different solution than the newly laid pavement which is prematurely rutting. While the construction technique may be the same, the materials used will probably be different. A knowledge of the pavement structure, the asphalt content, the physical properties of the extracted asphalt, the quality and gradation of the aggregate, and available technologies are essential to designing a new pavement which will be cost-effective, smooth and durable.

The most common techniques are Hot Recycling, Cold-In-Place Recycling, Hot-In-Place Recycling and Full Depth Reclamation. The asphalt products used range from conventional asphalt cement and standard SS-1 emulsified asphalt to emulsions made from blends of special chemical rejuvenating agents and polymer modified asphalt.