1. PROBLEM NUMBER
  1. PROBLEM TITLE

Guide Construction Specifications for Cold In-place Recycling (CIR) and Cold Central Plant Recycling (CCPR)

  1. RESEARCH PROBLEM STATEMENT

Pavement preservation is becoming an important activity for DOTs in maintaining and enhancing the condition of their highways. With the enactment of MAP 21 wherein the DOTs have to show improved performance in the conditions of their highways, the use of pavement preservation treatments will be crucial to meet the performance goals. Pavement preservation treatments are treatments that do not improve the structural capacity of a pavement, but do delay pavement deterioration. In the case of CIR and CCPR, they are considered a minor rehabilitation pavement preservation treatment when topped with a thin overlay, but can be used with a surface treatment for low volume roads as a pavement preservation treatment. They treat cracks of a higher severity than what other preservation techniques can treat, and the recycled layer istopped with a thin overlay to modify the pavement structure to produce a more long-lasting system.CIR and CCPR treatments are part of a sustainable strategy for reducing the need for new aggregate and new asphalt while using lower energy and creating fewer emissions.

Preservation treatments using asphalt emulsion as the binder have almost always been considered secondary to hot mix asphalt technologies and are therefore not as well understood. These technologies have not been upgraded or researched as much as HMA. However, over the last five years the FHWA PPETG (Pavement Preservation Expert Task Group) and ETF (Emulsion Task Force) have made a concerted effort to 1) improve the state of the science in emulsion technology, and 2) create consistent performance-based standards (specifications, test methods, design practices, etc.) that are sponsored by FHWA and / or AASHTO and are not vendor specific.

The rationale for creating AASHTO standards for pavement preservation treatments was to provide credence, and more importantly, buy-in from the DOTs. In order to implement any of these treatments into construction projects, material AND construction standards have to be created first, and in the case of CIR and CCPR, a mix design practice and material specifications have been created and submitted to the AASHTO Subcommittee on Materials (SOM). However, as noted in NCHRP Synthesis 421, one of the barriers to greater use of these treatments is lack of specifications. Development of guide construction specifications accounting for the best practices by agencies and contractors will greatly assist in increased use of these treatments, especially by agencies with little past practice with in-place recycling.

  1. LITERATURE SEARCH SUMMARY

Asphalt Recycling and Reclaiming Association. ARRA, Cold Recycling. Asphalt Recycling and Reclaiming Association, May 2009 [Online]. Available:

FHWA, Cold In-Place Asphalt Recycling Application Checklist,Publication FHWA-IF-06-012, U.S. Department of Transportation, Washington, D.C., 2005a [Online]. Available:

Mary Stroup-Gardiner, Synthesis 421, Recycling and Reclamation of Asphalt Pavements Using In-Place Methods, Washington DC, 2011

  1. RESEARCH OBJECTIVE

The objective of this project is to produce an AASHTO Construction Guide Specification for the application of cold in-place recyclingand cold central plant recycling. This will assist highway agencies to tailor their own specifications to the local conditions and environments. This will go a long way in getting DOTs to implement this treatment for their pavement preservation programs.

The research to produce the construction guide standards should include a review of previous work in this area. This should include a review of construction specifications and practices that are in use in several state DOTs already performing this work.

  1. ESTIMATE OF PROBLEM FUNDING AND RESEARCH PERIOD

Recommended funding:

$100,000

Research period:

12 months

  1. URGENCY, PAYOFF POTENTIAL, AND IMPLEMENTATION

The creation of this construction guide specification, together with the already drafted design practice and materials specifications, should make it easier for DOTs to implement this treatment.

MAP 21 and the required performance enhancements of the aging highway system makes it imperative that this effective treatment is used on a more regular basis.

  1. PERSONS DEVELOPING THE PROBLEM

The problem statement was developed with the support of the FHWA Emulsion Task Force (ETF). The ETF is made up of members from DOTs, FHWA, academia, and representatives of AEMA (Asphalt Emulsion Manufacturers Association), ARRA (Asphalt Recycling and Reclaiming Association), and ISSA (International Slurry Surfacing Association). The ETF has been working on creating standards for AASHTO and has delivered several materials standards related to pavement preservation.

Todd Thomas, Colas Solutions and chair of the Recycling Emulsions Subcommittee of the ETF

Steve Cross, Oklahoma State University and Technical Director of ARRA

Colin Franco, Rhode Island DOT

Anita Bush, Nevada DOT

Darren Hazlett, Texas DOT

Mike Voth, FHWA-CFLHD

Chris Lubbers, Kraton

  1. PROBLEM MONITOR

To be determined

  1. DATE AND SUBMITTED BY

October 20, 2016

Jon Wilcoxson - AASHTO Subcommittee on Maintenance