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Backcalculation of the Long-Term Pavement Performance Program Deflection Data

Project Information

Project ID: 
Project Status: 
Start Date: 
Friday, September 30, 2011
End Date: 
Tuesday, December 29, 2015
FHWA Program: 
FHWA Subprogram: 
Long-Term Infrastructure Performance
FHWA Activity: 
Long-Term Pavement Performance
FHWA Topics: 
Research/Technologies--Turner-Fairbank Highway Research Center (TFHRC); Research/Technologies--FHWA Research and Technology
TRT Terms: 
Pavement Performance; Backcalculation; Infrastructure; Pavements; Research; Falling Weight Deflectometers
FHWA Discipline: 
Pavement and Materials
TRB Subject Area: 
Highways, Materials, Pavements, Research

Contact Information

First Name: 
Yan (Jane)
Last Name: 
(202) 493-3149
Email Address: 
Long-Term Infrastructure Performance Team
Office of Infrastructure Research and Development
Office Code: 

Project Details

Project Description: 

This study shall first evaluate and decide on the most appropriate method(s) for backcalculation of the Long-Term Pavement Performance (LTPP) deflection data for different pavement types. Using the selected method(s), backcalculated moduli and related parameters shall be derived and integrated into the LTPP database.The research shall consist of two phases. The goal of phase I is to evaluate and select appropriate methodology for backcalculation of the LTPP deflection data, covering both flexible and rigid pavement structures. The process shall include literature and LTPP data reviews, and case studies on selected LTPP sections using candidate backcalculation methods. The contractor shall submit an interim report, including a detailed phase II work plan.


The main goal of this study is to select the appropriate methods and perform backcalculation of all the deflection data in the current Long-Term Pavement Performance (LTPP) database for flexible, rigid, and composite pavement sections. 


Deliverable Name: 
Final report and related documents
Deliverable Type: 
Research report or guidelines
Deliverable Description: 
The contractor shall prepare a final report documenting the work performed, findings from investigations performed, results, and suggestions for future research. In addition, the contractor shall prepare and submit a Long-Term Pavement Performance (LTPP) TechBrief. Feedback reports will also be submitted by the contractor to the Federal Highway Administration documenting any questionable data, discrepancies, or other data problems that need to be explained or corrected.
Deliverable Name: 
Backcalculation and data processing software developed
Deliverable Type: 
Deliverable Description: 
The contractor shall, with the final report, deliver the source, executable code, and a list of any third party off the shelf components used, and required Federal Highway Administration documentation for preprocessing and postprocessing of Long-Term Pavement Performance data and other software developed under this contract.
Deliverable Name: 
Long-Term Pavement Performance computed parameter tables
Deliverable Type: 
Deliverable Description: 
Analysis datasets developed for conducting backcalculation.Backcalculated computed parameter tables data, and related documentation.