Nondestructive Evaluation Laboratory Overview
What is Nondestructive Evaluation (NDE)?
Laboratory Purpose
Laboratory Description
Forensic Investigation and Technical Assistance
FHWA NDE Webinar Series
Other Accomplishments
Laboratory Capabilities
Laboratory Services
Laboratory Equipment
What is Nondestructive Evaluation (NDE)?
NDE is a means of analyzing and assessing the condition of various structural components of in-service highway infrastructure assets—pavement, bridges, and tunnels—without damaging them.
Laboratory Purpose
The mission of the Federal Highway Administration (FHWA) NDE Laboratory is to conduct state-of-the-art research, development, and implementation of nondestructive testing systems and technologies to improve the Nation’s highway infrastructure assets. Since its establishment in 1998, the NDE Laboratory has been maintained as an open resource for the FHWA, State departments of transportation (DOTs), industry, and academia. The NDE Laboratory fulfills the need for unbiased expertise to evaluate emerging NDE technologies, as well as data analysis, fusion, and interpretation.
Laboratory Description
The NDE Laboratory is a world-class facility for the development and testing of NDE technologies. FHWA has upgraded the NDE Laboratory with state-of-the-art NDE tools to support the program's mission, and to address the growing needs of FHWA and other stakeholders to improve the performance and reduce the lifecycle cost of highway-infrastructure assets.
Figure 1. Image. Artist’s rendition of the NDE Laboratory.
The The primary laboratory facility is a 9.4- by 8-meter facility (figures 1 and 2) with new equipment and tools, including a KUKA robotic arm (KR 10 R1100 six) with a payload of 10 kg to handle test specimens, NDE equipment such as a Full Matrix Capture Phased array ultrasonic testing (UT) system for the latest in flaw detection and imaging of steel component inspection, and three-dimensional augmented reality ground penetrating radar for better visualization of results from real time concrete inspection.
Figure 2. Photograph. The NDE Laboratory.
Forensic Investigation and Technical Assistance
Arlington Memorial Bridge
In response to a request on February 2015 by the FHWA Eastern Federal Lands Highway (EFL) office and the National Park Service (NPS), the FHWA NDE Laboratory in close coordination with the Long-Term Bridge Performance (LTBP) Program, provided technical assistance and evaluated the condition of the deck of the Arlington Memorial Bridge (AMB) using the RABIT™ bridge deck condition assessment robot and other advanced NDE technologies. The evaluation included condition evaluation and assessment of the deck with respect to:
- The concrete quality (degradation) and the corrosive environment.
- The extent and severity of delamination and overlay debonding in the deck.
FHWA EFL was briefed about the findings of the AMB testing and evaluation. Maintenance and management alternatives and recommendations were discussed in the briefing.
Yerba Buena Tunnel
In January 2016, a chunk of concrete from the tunnel liner fell into the travel way of the Yerba Buena Island Tunnel. In response to this event, the California Department of Transportation (Caltrans) immediately conducted an indepth visual inspection and sounding of the tunnel lining walls and identified additional areas of distress. This issue has raised Caltrans Management’s concern about the public's confidence in using the tunnel. Because of the sensitivity of this issue, Caltrans requested that the FHWA provide an independent evaluation of their assessment of the tunnel lining condition. To support FHWA’s work, Caltrans provided traffic control and the equipment needed to access the tunnel lining (e.g., bucket lifts to access the top 5 feet of the tunnel walls).
To assist Caltrans to validate their sounding results, the FHWA team conducted comprehensive non-destructive testing using different NDE techniques on the eastbound side of the Yerba Buena Tunnel, including:
- LiDAR (Light Detection and Ranging)
- Infrared Thermography (IR)
- Impact Echo (IE)
- Ground Penetrating Radar (GPR)
- Electrical resistivity (ER)
FHWA NDE Webinar Series
The FHWA NDE Program offers monthly webinar series. This webinar series serves as a collective experience with the goal of sharing more about the adoption of various NDE technologies by Government, State and local transportation agencies, and current projects, challenges, and best practices. The presentations are monthly, alternating between pavement-themed topics and a focus on bridges and tunnels. During these webinars, you will learn about government, State and local transportation agencies' NDE experiences; and the successes of local agencies.
The webinars are geared toward State highway and local transportation agencies, suppliers, consultants, academia, and the transportation community.
All webinars are free to attend and are tentatively scheduled for the fourth Monday of each month at 1:00 p.m. (Eastern Standard Time (EST)). Please contact Hoda Azari, Hoda.Azari@dot.gov, for more information.
Other Accomplishments
InfoTechnologySM, which replaces the NDE web manual, is a web tool for assisting practitioners, service providers and researchers with proper selection of NDE technologies for the condition assessment of highway infrastructure components. This manual, a product of an FHWA Strategic Initiative project, presents a comprehensive selection and description of NDE technologies to fill a gap between the practitioners dealing with performance of their assets on a day-to-day basis and the researchers developing and refining NDE technologies. This version of the InfoTechnology presents current, unbiased, and reliable information about NDE technologies for bridges, tunnels and pavements, including the application, description, physical principle, data acquisition, data processing, data interpretation, advantages, and limitations of each NDE technology. Future versions of the InfoTechnology would include information about applications of other sensor technologies.
FHWA NDE Strategic Plan for FY 2019-2022
In 2019, the FHWA published the FHWA Nondestructive Evaluation [NDE] Program Strategic Plan for FY [fiscal year] 2019–2022, which outlines a strategic framework of goals, objectives, and strategies to allocate resources to the most pressing needs in the area of nondestructive condition assessment. This strategic plan was a result of extensive discussions and feedback with stakeholders at various webinars and technical working groups, and aligns its objectives, related program initiatives and performance measures with those of the USDOT and FHWA’s strategic plans. The NDE Program strategic plan also outlines seven topical areas of high- and medium-priority research that were identified through discussions with FHWA and external stakeholders.
FHWA NDE and Structural Health Monitoring Workshop
Workshop Summary
In June 2016, the FHWA convened a diverse group of experts at the National Academies of Science to develop, discuss, and debate future research directions for existing and emerging assessment technologies (inclusive of both (NDE) and structural health monitoring (SHM). As a follow up to that workshop, the FHWA NDE Program hosted a workshop on Oct. 26–28, 2022, at Turner-Fairbank Highway Research Center (TFHRC). The workshop presentations and discussions centered on the added values of NDE and structural monitoring (SM) and what opportunities exist to integrate them with asset management. The workshop discussed future steps and needs related to SM, as well as opportunities and approaches to integrate NDE with asset management.
The workshop’s presentation and discussions centered on achieving the following: better understanding of the current policies and practices for how bridges are managed and maintained by State DOTs, improvements in supplying data-driven solutions for bridge owners, new and improved resources for NDE and SM users, and identification of future research needs.
Motivation and Objectives
From a broad perspective, the first overarching aim of the workshop was to begin to foster communication and collaboration between the end-users of NDE/SHM technologies and the researchers that are engaged in their development and refinement. The second overarching goal of this workshop was to bring NDE and SHM communities together to promote and identify opportunities for the integration of NDE and SHM.
In addition to these broad objectives, the following more detailed goals were also identified to ensure tangible products that may make near-term impacts on the field.
- Identification of guidance needs, strategies, and delivery mechanisms to effectively promote and enable the effective adoption of SHM approaches by end-users.
- Development of an NDE research roadmap for transportation infrastructure (inclusive of integration opportunities with SHM).
Summary of Key Workshop Outcomes
Throughout the 2016 workshop a strong consensus emerged that the integration of end-user and research perspectives together with collaboration between NDE and SHM researchers is essential to moving the use of assessment technologies forward. To maintain the momentum developed during the workshop, it was strongly recommended that FHWA work to develop a diverse government-industry-academe working group that meets regularly to continue to debate and discuss the issues surrounding NDE and SHM research and implementation. Although there are several NDE- and SHM-focused committees at numerous professional societies, none include the auspices of the American Association of State Highway and Transportation Officials (AASHTO) Subcommittee on Bridges and Structures. This was viewed as a significant shortcoming.
Six priority research topics were identified and categorized under three primary research thrust areas. These included developing new technologies to fill the gaps in existing NDE technologies, improved data analysis, and integration of NDE technologies in the decisionmaking process.
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Thrust Area 1: Expansion of NDE Capabilities – Development of new NDE approaches to detect and track defects, identify characteristics, or measure responses that cannot be accomplished with current methods.
Thrust Area 2: Improvement of NDE Data Interpretation – Development of data processing, fusion, analysis, visualizations, etc. methods to allow for more reliable and cost-effective data interpretation.
Thrust Area 3: Incorporation of NDE Methods within Total Asset Management- Identify strategies and overcome barriers that limit the incorporation of NDE methods within decisionmaking frameworks.
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The key outcomes of the 2022 workshop listed below:
Current policies and practices for bridge management and maintenance.
- Conduct a comprehensive review of current practices and policies of State DOTs engaged in the use of NDE to complement bridge visual.
- Identify “lead adopter” users of NDE and document existing case studies; level of maturity of NDE usage; guidelines and specifications used for data collection; NDE technology usages for managing assets at the project or network level; results states and whether/how they are translated to condition- rating standards for use in asset management systems; implementation barriers and success factors for NDE usage; and quantifications of how NDE usage added value.
- Describe NDE techniques as either predictive NDE or defect detection NDE and identify how these techniques can be used to predict potential areas of future damage or directly supply condition -state data for asset management systems, respectively.
- Describe how predictive and defect detection NDE techniques are used, individually, and/or together over the course of an asset lifespan to better manage an asset.
- Describe how NDE data storage might be incorporated with FHWA’s Building Information Modeling digitization efforts.
Added value and return on investment (ROI) for the integration of NDE technologies into asset management.
- Make recommendations on how to improve and advance current bridge inspection procedures with a view toward the future of data-driven infrastructure condition assessment policies and how NDE will be incorporated into asset management systems.
- Create a plan to develop a tool(s) that describes the added value and ROI related to NDE applications for bridge management.
- Upon approval of the plan, develop the tool(s) and validate with case studies or “lead adopter” agencies.
Improve NDE standards and guidelines.
- Identify available NDE standards and guidelines, and for those technologies with a lack of standards, make recommendations for how standards can be developed.
- Develop NDE standards for both project- and network-level asset management applications.
Future research needs.
- Use an NDE factor integrate NDE data into asset management, similar to current environmental and protection factors. This represents a promising approach at the project level, however significant research over 10 to 20 years would be required to collect the data needed to calibrate the NDE factor and combination factors when multiple technologies are utilized. Efforts such as the LTBP Program are poised to support this type of future research.
- Develop scenario building tools for asset management that allow high-level decision-makers the ability to study the financial impact of approaching network-level bridge assessment differently using data-driven NDE tools.
- Advance efforts to develop NDE equipment capable of network-level data collection that are automated, low cost, and can be executed at highway speeds or with minimal traffic disruption.
- Develop a data standard for a simplified metric collected by NDE and execute these test(s) on a large population over a sustained period to validate the feasibility of a network-level NDE approach.
FHWA Workshop in Advanced Ultrasonic Inspection Applications for Steel Bridge Welds
WORKSHOP SUMMARY
FHWA and the National Steel Bridge Alliance cohosted an NDE workshop at TFHRC on May 31 and June 1 entitled “Advanced Ultrasonic Inspection Applications for Steel Bridge Welds.” Cutting-edge NDE techniques are under investigation at TFHRC as a possible alternative to radiography for the inspection of steel welds in new fabrication bridges. The techniques are also of interest for application on in-service bridges to monitor known or suspected problematic flaws. The workshop included approximately sixty representatives from State transportation agencies, FHWA, U.S. Army Corps of Engineers, advanced ultrasonic system equipment manufacturers, academia, and contractors.
MOTIVATION AND OBJECTIVES
The workshop primarily focused on the emerging phased array UT PAUT technique and full-matrix capture/total focusing method (FMC/TFM). The FMC/TFM technology is an industrial spinoff of advanced image processing techniques used in radar, sonar, and medical imaging applications. The concept is similar to the relatively old synthetic aperture focusing technique (SAFT) for image processing, but the multiple sensor location information required by SAFT is obtained by the multi‑element PAUT probe in lieu of multiple single sensor locations. The availability of more powerful computing capability in laptops and portable ultrasonic equipment has enabled ultrasonic equipment manufacturers to further develop and bring this image processing capability to the field for real-time high-resolution imaging.
SUMMARY OF KEY WORKSHOP OUTCOMES
The images provided by the FMC/TFM process result in improved weld-flaw sizing and characterization information. The improved flaw sizing and characterization is of interest to owners of existing bridges with weld flaws that need to be evaluated in detail for repair or monitored. The improved flaw information provides engineers with more reliable information to assess the significance of these known flaws. For new fabrication bridges, this FMC/TFM technology has the potential to be used to support the elimination of radiography from the bridge fabrication specification American Welding Society (AWS) D1.5. Radiography is a costly inspection method when compared to ultrasonics and comes with scheduling and radiation hazard concerns. At the workshop, numerous bridge fabricators commented on their interest in eliminating the radiography requirement.
With overall positive enthusiasm by the attendees to further evaluate and pursue this technology, followup actions were identified at the end of the workshop. These plans include a more detailed evaluation of the FMC/TFM technique at a bridge fabricator’s facility, possibly on the production line of new steel bridge girder fabrication welds.
Laboratory Capabilities
FHWA has recently renovated and upgraded the NDE Laboratory to address the growing research needs of stakeholders. Current expertise at the laboratory includes: conventional PAUT; conventional/advanced eddy current testing; acoustic emission; ground penetrating radar testing; infrared thermography testing; impact echo testing; surface wave testing; SHM systems; noncontact and remote sensing; numerical simulation; automated data collection, analysis, interpretation, visualization and data fusion. In conjunction with this expertise, an extensive collection of concrete/steel specimens and commercial test equipment are available at the NDE Laboratory.
Laboratory Services
The NDE laboratory conducts state-of-the-art research, development, improvement and implementation of NDE systems and technologies to assist infrastructure owners. This work includes condition assessment of in-service tunnels, pavements, and bridges, as well as providing technical assistance and forensic investigation services in examining the nature and causes of anomalies or failures of highway infrastructure assets.
Laboratory Equipment
The NDE Laboratory maintains an extensive collection of commercial and emerging test equipment. Click here for a more detailed list of equipment.
- Loading Frame and Environmental Testing Chamber
- Laboratory-based large specimen scanning systems: XY Scanner and Robot Scanner
- Concrete Electrical Resistivity Meter
- Galvanostatic Pulse Measurement (GPM) System
- GPR System
- Half-Cell Potential (HCP) Corrosion Analyzing Instrument and Probe
- Impulse Response (IR) Testing System
- Infrared Thermography Camera
- Ultrasonic Pulse Echo (UPE) System
- Ultrasonic Surface Waves (USW) Testing System
- Portable Automated Acoustic Array System
- Acoustic Emission Data Acquisition System
- Pavement Compaction Testing System
- Eddy Current Testing (ECT) Instrument and System
- Full Matrix Capture Phased Array System
- Portable PAUT
- Ultrasonic Testing (UT) Device
Last updated: Monday, July 1, 2024