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Public Roads - July/August 2016

July/August 2016
Issue No:
Vol. 80 No. 1
Publication Number:
Table of Contents

Internet Watch

The Web Manual for Nondestructive Evaluation Technologies

by Carrie Boris

To maintain the performance of highway systems, transportation agencies must be able to assess the condition of structural elements without damaging or altering them. Nondestructive evaluation (NDE), which complements visual inspection, is a means by which they can assess structural components of inservice highway infrastructure without impairing future usefulness.

To centralize and better coordinate research related to nondestructive testing, the Federal Highway Administration established the NDE Validation Center, now called the FHWA Advanced Sensing Technology (FAST) NDE Laboratory, in 1998.  The lab’s mission is to conduct state-of-the-art research and development and to support implementation of nondestructive testing systems and technologies to improve the Nation’s highway infrastructure assets, including bridges, pavements, tunnels, and other structures.

To support its mission, the laboratory produced the NDE Web Manual, a comprehensive collection of techniques and methods to aid practitioners in selecting and properly applying NDE systems. Experts on each technology helped to develop and independently review the content of the manual. Currently, the manual covers various structural elements of steel and concrete bridges. Planned expansions will include information for pavements and tunnels, as well as bridge substructures.

Focusing on the Problem

Launched in September 2015, the NDE Web Manual fills a critical knowledge gap between the practitioners dealing with the challenges of bridge performance and the researchers developing and refining NDE technologies to serve them.  The manual contains concise and unbiased guidance to help users navigate complexoptions and identify the technologies that can serve their specificneeds.

“When a bridge needs indepth assessment beyond visual inspection, sifting through a wide variety of technologies to find one that might help is not easy,” says Dr. Hoda Azari, manager of the NDE lab.  To make the NDE Web Manual more accessible to practitioners, developers created it to be a “problem-focused” rather than “technology-focused” tool. “The manual aims to address the common scenario in which a practitioner has already identified a specific infrastructure element or type of anticipated deterioration or defect and is seeking an NDE technology to provide better characterization,” explains Azari.

The simple interface under the “find technology” tab enables users to search for technologies and methods relevant to specific materials, types of deterioration, and infrastructure elements. For example, selecting “steel” under the materials column presents a list of five structure elements. Choosing an element then presents a list of relevant concerns, such as corrosion, cracking, and weld defects. When the user selects one of these targets of investigation, the manual provides a list of recommended technologies for consideration.

A Comprehensive Report

A technology report, based on user selections, consists of three tabs: the chosen NDE technology, the target of investigation (such as cracking), and the structure element. Each technology page provides a description and information about the application; the foundational physical principles; and the data acquisition, processing, and interpretation.  The page includes the advantages and limitations of the technology, illustrative photographs or diagrams, and related references.

The tabs for the selected target of investigation and structure element provide brief descriptions of those items. Clicking on the “display report” button at the top of the technology page produces a print-friendly version that includes all information and photos from the three tabs. Links at the top of each report Web page enable the user to see his or her current selections.

If a practitioner simply wants more information about a specific technology, the site includes a drop-down menu of NDE technologies divided by material: concrete or steel. Additional tabs provide a comprehensive glossary and list of acronyms and abbreviations.

“We want the manual to be very useful for practitioners,” says Azari. “It does not simply regurgitate the detailed technical literature that may be largely irrelevant for end users, but offers explanations of NDE test procedures, sample applications, and results, in a very easy-to-use format.”

For more information, visit or contact Hoda Azari at or 202–493–3064.




Carrie Boris is a contributing editor for Public Roads.