AMRL to Certify Falling Weight Deflectometer (FWD) Calibration Center Operators
A Falling Weight Deflectometer (FWD) is a non-destructive testing device used to measure pavement deflections in response to a high-amplitude dynamic load. The devices are used to simulate the load applied by truck traffic. Vertical deformation of the pavement, caused by a controlled load, is measured using deflection sensors. This information is used to determine the expected life of the pavement, overlay thickness requirements, and load capacity.
There are approximately 200 FWDs used in the United States, and the more than 400 FWDs used worldwide. Many of these FWDs are calibrated annually in accordance with AASHTO R 32 to ensure proper function and accuracy of the data collected. The calibration is generally performed by a certified FWD calibration center operator.
In 1987, the Strategic Highway Research Program established 4 centers for the purpose of calibrating FWDs in the United States. That number has since risen to include several centers worldwide. Until just recently, FWD calibration center operators were certified by a team of experts from Cornell University as part of a Federal Highway Administration (FHWA) Pooled Fund Study. Since the pooled fund study will be ending on October 31, 2010, the FHWA has asked AMRL to take over the responsibility of conducting the evaluation and certification of the center operators.
Over the past 18 months, AMRL staff have received extensive hands-on training from industry experts at the Cornell Local Roads Program. AMRL will officially take over the responsibility of conducting the annual calibration center operator evaluations and certifications this Fall.
Technical support will be handled primarily by AMRL, with assistance from the Cornell Local Roads Program, if the need arises. The FHWA will continue to provide oversight to the certification program.