The National Academies

SHRP 2 R06(F) [Completed]

Development of Continuous Deflection Device

  Project Data
Funds: $250,000
Research Agency: Virginia Tech
Principal Investigator: Gerardo Flintsch
Effective Date: 4/29/2009
Completion Date: 5/31/2012

Project snapshot. More details below.

(Project Number)
Impact on Practice
Product Status

Catalog of devices for measuring continuous deflection and detailed evaluation of traffic speed deflectometers, detailed assessment of the most promising devices, case studies, fact sheets, training materials for a workshop on the topic, research needs statements, and a dissemination and implementation plan for the technology.
Continuous deflection measuring devices are increasingly used to support pavement management business processes. Techniques that don’t disrupt traffic are of special interest. The evaluations identified promising characteristics of these young technologies and areas for future development. They have advanced network-level data collection and show promise for project-level use.
The final report is available at www.trb.org/Main/Blurbs/167283.aspx.

Staff Responsibility: James Bryant

The structural capacity of pavement is a critical input for performing structural analysis of in-service pavements, identifying sections with structural capacity deficiencies at the network level, and designing pavement renewal or rehabilitation treatments at the project level. The use of continuous deflection measuring devices, which in some cases operate at traffic speed, allows for better spatial coverage with less impact on traffic. The currently available continuous devices are becoming increasingly popular as a practical alternative to stationary falling weight deflectometer (FWD) devices, especially for network-level structural monitoring.

The objective of this project was to critically assess the potential of existing continuous deflection devices as a practical and cost-effective tool for use in the development of optimum pavement rehabilitation strategies on rapid renewal projects.

This project evaluated current technologies implemented in continuous deflection measuring devices. The demand and the potential value of continuous deflection devices for supporting pavement renewal decisions were assessed, and the technologies best suited for effectively supporting the most critical decisions were identified by the potential users through a survey of state departments of transportation.  The study produced a catalogue of existing continuous deflection measuring technologies and their characteristics. The capabilities of two devices that showed the most promise to be ready for production use were reviewed. Practical applications for supporting pavement management decision-making were identified and illustrated.

Status: This project is complete.

Product Availability: The final report is available.

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