The National Academies

NCHRP Synthesis 20-05/Topic 55-04 [Active (Synthesis)]

Current Practices and Guidelines for Full-Depth Reclamation (FDR)
[ NCHRP 20-05 (Synthesis of Information Related to Highway Practices) ]

  Project Data
Funds: $55,000
Staff Responsibility: Edward T. Harrigan
Research Agency: Jo E. Sias
Principal Investigator: Jo E. Sias
Effective Date: 10/15/2023
Completion Date: 4/15/2025
Fiscal Year: 2024

Final Scope of Work

Full-Depth Reclamation (FDR) is an in-place recycling method for reconstruction and rehabilitation of flexible pavements, as well as construction of new alignments, that uses existing materials as the base for a new surface wearing course. By making effective use of the pavement, paving projects using FDR may be sustainable and may achieve reduced costs. Pulverized roadway materials may be blended with stabilizing additives such as emulsified asphalt, foamed (expanded) asphalt, calcium chloride or Portland cement to form a stiff base layer. FDR is a widespread practice, but state departments of transportation (DOTs) have diverse construction practices and quality assurance procedures for FDR. 

The objective of this synthesis is to document current state DOT practices and guidelines for the use of FDR. 

Information to be gathered includes (but is not limited to):

·         Existing specifications and guidelines related to FDR mix design.

·         State DOT classification of FDR types.

·         FDR design criteria and consideration of traffic loads and environment conditions.

·         Site selection and pre-design investigation for FDR.

·         Post-construction verification of FDR properties.

·         Properties of FDR base used in pavement design.

·         Current practices in FDR construction and QA.

·         Mix design and test methods to evaluate FDR quality, e.g., Superpave gyratory compaction, modulus, stiffness, curing time, long-term strength gain, etc.

·         Selection of stabilization additive, e.g., cement, aggregates, foamed asphalt, emulsified asphalt.

·         Tests to make time-critical decisions regarding opening to traffic and surfacing of the FDR base, such as raveling resistance using a short-pin raveling test and shear resistance using a long-pin shear test.

·         Performance and cost effectiveness of different methods used to mitigate cracking in hot mix asphalt (HMA) overlay on the (stabilized) FDR layer, such as crack relief layer, micro-surfacing, chip-seal, microcracking, etc.

·         Efforts to quantify the sustainability of FDR.

·         Life-cycle cost analysis of FDR by DOTs.

·         Potential to utilize quarry by-products (QB) in FDR.

·         Time savings during construction. 

Information in this synthesis will be gathered through a literature review, a survey of state DOTs, and follow-up interviews with selected agencies for the development of case examples. Information gaps and suggestions for research to address those gaps will be identified. 

TRB Staff
Edward Harrigan
Email: eharrigan@nas.edu

Mobile: 540-454-2149

Meeting Dates
First Panel Meeting: September 12, 2023 (Virtual)
Conference Call: September 22, 2023 
Second Panel Meeting: July 15, 2024 (Virtual)

Panel Members

Cathrina Barros, California Department of Transportation

Rueben Carrasco, Texas Department of Transportation

Brian Diefenderfer, Virginia Transportation Research Council

Colin Franco, Rhode Island Department of Transportation

Daba Shabara Gedafa, University of North Dakota

Jusang Lee, Indiana Department of Transportation

Christopher Lundgreen, Washington State Department of Transportation

Kimberly Lyons, South Carolina Department of Transportation

Raquel Moraes, National Center for Asphalt Technology

Nelson Gibson, TRB Liaison

Jason Dietz, FHWA Liaison

To create a link to this page, use this URL: http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=5471