FHWA NDE CENTER RESEARCH & DEVELOPMENT
Advanced Ground-Penetrating Radar Inspection of Bridge Decks
The Federal Highway Administration (FHWA) has sponsored the development
of advanced ground-penetrating radar (GPR) systems for the inspection of bridge decks. Two radar systems have been designed
and built by Lawrence Livermore National Laboratory (LLNL) under this research program. The HERMES bridge inspector
(High-speed Electromagnetic Roadway Mapping and Evaluation System) is designed
to survey the deck condition during normal traffic flow. Surveys at a variety of traffic speeds have been conducted. This system is
based around a 64 channel antenna array covering 1.9 m in width with a sampling density of 3 cm.
 |
 |
HERMES bridge inspector |
PERES bridge inspector |
To investigate specific areas of a bridge deck that require detailed inspection,
a slower cart mounted radar has been produced. This system is named PERES (Precision Electromagnetic Roadway Evaluation
System). The density of data coverage with PERES is 1 cm and an average of 100 samples is taken at each location to improve the
signal to noise ratio. Images of the bridge deck interior are reconstructed from the original synthetic aperture data using wavefield
backpropagation techniques. The goal of these systems is to locate steel reinforcement, corrosion related delaminations, voids
and debonds. The final goal for these systems, and other non-destructive technologies, is to provide information on the condition
of the nation's bridges.
For more information, please contact either by e-mail or telephone.
Frank Jalinoos (202) 493-3082
frank.jalinoos@fhwa.dot.gov
The Problem of Deteriorating Bridge Decks
The HERMES Bridge Inspector
The PERES Bridge Inspector
Current Work on Hermes II
