The first project in the second Strategic Highway Research Program (SHRP 2) in the field of nondestructive evaluation (NDE) was completed in 2008. The project evaluated the existing and emerging NDE technologies and their state of implementation to satisfy NDE requirements for highway renewal. For the requirements not yet addressed with fully implemented NDE techniques, a research plan was devised for developing technologies to deal with the most pertinent requirements for bridges, pavements, tunnels, soils, and retaining walls through the life of the facility. The findings of this project related to NDE and its recommendations for subsequent research work in this area are presented in this report. The strategic objective of highway renewal research in SHRP 2 is to develop the necessary tools to “get in, get out, and stay out” when renewing the existing highway infrastructure. To accomplish the goals implied in this motto, technologies and processes that yield long-lasting facilities through rapid design and construction approaches while minimizing the impact to highway users are needed. Nondestructive testing (NDT) techniques that can pro-duce rapid inspection of new construction would facilitate timely reopening of a highway after reconstruction. Adequate NDT techniques are also needed to ensure the quality of construction required for long-term performance. Under SHRP 2 Project R06, a research team led by Andrew Wimsatt of the Texas Transportation Institute thoroughly reviewed existing and emerging NDE technologies, evaluated the existing inspection requirements, and developed a research and development (R&D) plan to address those requirements. Initial tasks in the research focused on gathering data from literature reviews, surveys, and in-person interviews with state departments of transportation in the United States, members of the Forum of European National Highway Research Laboratories, academia, and industry. The data-gathering activities identified existing NDE techniques and practices, emerging technologies, and apparent gaps between current and future inspection requirements and existing and emerging technology. The R&D plan was developed to address the gaps. The main audience for the R&D plan is the SHRP 2 Technical Coordinating Committee for Renewal, which will use the plan to program additional research funds for NDE. The information in this report has the potential to facilitate other agencies’ research plans in this field; thus, other research organizations and funding agencies are also possible audiences. The research team identified more than 20 areas of study that must be addressed with sub-sequent research. The team also provided detailed recommendations to address the top six research needs: • Automated methods of accurately profiling bridges; • Changes in profiles of tunnel linings over time; • Identification of bridge deck deterioration, including its cause; • Continuous deflection device at the highest possible speed for pavements; • New NDT quality assurance tools for ensuring quality construction; and • Measurement of interlayer bonding between hot-mix asphalt layers for pavements. (Author/publisher)
Samenvatting