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Better, faster methods for determining concrete bridge deck conditions

Nondestructive Testing for Concrete Bridge Decks (R06A)


The number of concrete bridge decks in poor structural condition is one of the biggest problems affecting bridges in the United States. Evaluating bridge deck conditions becomes increasingly critical as highway agencies work to optimize the effective timing, scope, and approaches for preventive maintenance, repair, and replacement.

Normal chain dragging, hammer sounding, and visual methods of identifying concrete bridge deck deficiencies do not accurately and safely provide the needed information to adequately maintain concrete bridge decks. Nondestructive testing (NDT) techniques have the potential to quickly and reliably provide the needed information about under-the-surface conditions of bridge decks, but independent evaluations are needed to determine their best use and to validate their effectiveness under a variety of conditions.


The web-based, open-source NDToolbox helps identify and characterize testing technologies that are available to locate the primary deficiencies in concrete bridge decks. With the toolbox, users can explore different NDT technologies and examine their use in detecting deterioration for conditions relevant to the project. The NDToolbox describes the technology and the physical principle behind it, applications, performance, limitations, equipment, test procedures and protocols, and sample results. It also provides recommendations regarding the best technologies for a particular deterioration detection application.

The accompanying report identifies the four most common types of deterioration affecting concrete bridge decks, and the corresponding NDT techniques that are best suited to locating and identifying the deterioration. Based on their overall value in detecting and characterizing deterioration in concrete decks, the top technologies were ground-penetrating radar, impact echo, and ultrasonic surface waves. The report and web tool provide clear information about the advantages and limitations of each technology. However, the ultimate decision about which equipment to acquire and which technology to use is dependent on the type of deterioration that is of highest concern to the agency, and whether the evaluation is being done for network-level condition monitoring or for project-level maintenance or rehabilitation.


Comprehensive and accurate assessments of concrete bridge decks can reduce the frequency of detailed regular and follow-up inspections. This can reduce the number of congestion-related traffic interruptions, which, in turn, can provide shorter durations and frequencies of work zones during testing operations. In addition, a number of NDT technologies can generate data at production rates that are comparable to the current practice of chain dragging and hammer sounding. The cost of these techniques is also approaching traditional testing values.

In the Field

State Project Description Activity Contact
Florida Implementation Assistance Program – The Florida Department of Transportation is supporting bridge rehabilitation by the use of technologies that can detect and quantify concrete defects for plan production. The technology will become a part of routine bridge inspections and eventually increase efficiencies in bridge inspections and problem detection. Lead Adopter Will Watts
Indiana Implementation Assistance Program – The Indiana Department of Transportation is expanding its use of NDT tools from project level planning to network level planning as well as the integration of the data into Network Based Asset management tools. Lead Adopter Jeremy Hunter
Iowa Implementation Assistance Program – The Iowa Department of Transportation has identified impact echo as one of the most promising technologies for bridge deck evaluation. They will purchase an impact echo system for more extensive evaluation and use on additional bridge decks. Lead Adopter Ahmad Abu-Hawash
Louisiana Implementation Assistance Program – The Louisiana Department of Transportation plans to use NDT methods as part of routine inspections. This will be accomplished through technical support, training, and usage of the technology so that in-house personnel may interpret data received by vendors. Lead Adopter Haylye Brown
Missouri Implementation Assistance Program – The Missouri Department of Transportation is utilizing a Wenner probe to test bridge decks and is interested in learning the scope and limitations of this tool and whether contract based bridge maintenance is a cost effective tool. Lead Adopter Andrew Hanks
Oregon Implementation Assistance Program – The Oregon Department of Transportation is evaluating two groups of bridge decks for either delamination or deterioration due to corrosion using various NDT technologies. The results will be evaluated by a subject matter expert. Lead Adopter Corey Withroe
Pennsylvania Implementation Assistance Program – The Pennsylvania Department of Transportation will assess and utilize different NDT technologies on three bridges of different lengths and structures to ascertain what technology should be used for a given condition. Lead Adopter Anthony McCloskey
Virginia Implementation Assistance Program – The Virginia Center for Transportation Innovation and Research will apply NDT technology for assessment and rehabilitation of a series of six bridges along a heavily traveled Interstate corridor. If this pilot is successful, use of the technology could be expanded to conduct evaluation and prioritize bridges along other interstate and primary corridors. Lead Adopter Adam Matteo
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