Cold-In-Place Recycling

Excerpt from the December 2022 issue of Asphalt Pro Magazine By: Sarah Redohl

A recent project to rehabilitate 41 miles of scenic mountain highway in Colorado reaches new heights of smoothness following one of the largest cold-in-place recycling treatments in the west.

A cost-effective, long-lasting, greener alternative to conventional maintenance and rehabilitation techniques. Cold In-place recycling (CIR) is a process that cold mills and recycles the top 2-5 inches of asphalt using a continuous train operation. Through the complete reuse of existing material, CIR greatly reduces trucking, time and natural resources to significantly lower project costs. Generally, any road that is a candidate for mill & fill is a candidate for CIR.

CIR Recycling Has Many Benefits

  1. 20%–50% less expensive than conventional maintenance and reconstruction methods
  2. Reduces greenhouse emissions by up to 90%
  3. Reuses 100% of existing materials
  4. 20%–40% faster construction times
  5. Adds 15–20 years (combined with appropriate wearing course)
  6. Most agencies use Structural Layer (a) Coefficients between 0.30–0.38 (Recent research indicates values from 0.36–0.44 may be more appropriate)

Since 1956, Asphalt Materials has focused on the asphalt business, specifically formulation, manufacturing, and R&D of asphalt binders and emulsions. Our teams are dedicated to tackling our industries’ biggest challenges. Creating longer-lasting, safer roads is only possible through close collaboration with our customers, suppliers, and partners.

We recently published a series of educational videos about the benefits of recycling technologies, processes and products. Here is one about CIR.

Issues Addressed with CIR

  • Frequent, severe, non-load distresses in top lift of hot mix
  • All distress within the recycling depth (2-5 inches)
  • Reflective cracking from below CIR layer

Benefits of CIR

  • Eliminates defects within the recycling depth
  • Blocks or slows reflective cracking
  • Reuses existing material in place
  • Replaces 1 or 2 lifts of hot mix
  • Allows for road widening where desired

AsphaltPro Magazine

AsphaltPro is a magazine serving the asphalt industry with a regular rotation of high-quality content integral to running a successful asphalt plant or paving operation. Published 11 times each year, AsphaltPro delivers the information you need to improve safety, efficiency, and performance.

Whether that’s information on upcoming legislation, training opportunities, ideas and best practices from industry experts, the latest technology, and the newest equipmentAsphaltPro has you and your crew covered. Learn more here:


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2 – Asphalt Pro Magazine, December 2022 Edition

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