FREE TRAINING FEATURE

FREE TRAINING FEATURE

Want to learn more about pavement management, in-place recycling, and pavement preservation? Do you feel like you're setup for failure as an agency engineer with little or no money to spend on your roads? Enter your email below to get free instant access to a two-hour video-training session that Blair did for the Northwest Pavement Management Association:

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Blair Barnhardt

Hot In-Place Recycling

Per the ARRA definition, Hot In-Place Recycling (HIR) is an on-site, in-place method that rehabilitates deteriorated bituminous pavements and thereby minimizes the use of new materials.  One of the best testimonials for the Hot In-Place Recycling process comes from Joe Thompson, Commissioner of Cobb County,GA.  To view this testimonial please click on Mr. Thompson’s name.

This process may be performed as either a single pass (one phase) operation that monolithically recombines the restored pavement with virgin material, or as a two pass procedure, wherein the restored material is recompacted and the application of the new wearing surface then follows a prescribed interim period that separates the process into two distinct phases.

HIR provides a very low cost maintenance strategy that enables the public works official to effectively re-use existing materials.  This process demonstrates that asphalt is a rather unique construction material in that it can be effectively and economically restored.  Rather than bury the deteriorated pavement with inordinate depths of new material conventionally applied, or lose it to the grinder, proponents of HIR encourage restoration.

HIR effective addresses the classic symptoms of deteriorated pavement:

  • Cracks are interrupted and filled
  • Aggregate stripped of the bitumen is remixed and recoated
  • Ruts and holes are filled, shoves and bumps are leveled, drainage and crowns are re-established
  • Flexibility is restored by chemically rejuvenating the aged and brittle pavement
  • Aggregate gradation and asphalt content may be modified by some variations of this process
  • Highway safety is enhanced through improved skid resistance

In a period of rapidly increasing costs and limited funding, Hot In-Place Recycling presents the opportunity to spread available dollars over a much greater area.  Roadway deterioration can be suspended, pavements preserved and upgraded, and costly reconstruction avoided.

HIR provides the owner agency the opportunity to reuse valuable resources that they have already bought and paid for.  The agency performing the work typically rehabilitates 30% more asphalt roads per year by choosing this method in lieu of conventional milling and inlaying.

Generally, these Hot In-Place Recycled mats are covered up with a wearing course of Slurry, Micro Surfacing, or thin asphalt overlays.  For the most part, an agency candidate for HIR should have a minimum of 2″-3″ of asphalt in-place before rehabilitation.  For a sample specification for HIR, click here. It is also important to note, that because of the size of the equipment and the limited number of contractors performing this work in America,  the minimum job size should be 50,000 square yards.

Hot In-Place surface recycling 1.5" nominal depth

Hot In-Place surface recycling 1.5" nominal depth

Hot In-Place surface recycling, Cook County, IL

Hot In-Place surface recycling, Cook County, IL

HIR Remixing Train

HIR Remixing Train

HIR Repaving, Scottsdale, AZ

HIR Repaving, Scottsdale, AZ