This report documents the work conducted under Phase 2 of Strategic Highway Research Program (SHRP 2) Renewal Project R06G. Renewal Project R06G seeks dependable non-destructive testing (NDT) techniques that minimize disruption to traffic. The objectives of the proposed research are as follows: • Identify NDT technologies for evaluating the condition (e.g., moisture, voids, and corrosion) of various types of tunnel linings (e.g., unreinforced concrete, reinforced concrete, shotcrete, and steel) and tunnel lining finishes such as tile. The techniques must be capable of analysing conditions within the tunnel lining and the surrounding substrate. • Evaluate the applicability, accuracy, precision, repeatability, ease of use, capacity to minimize disruption to vehicular traffic, and implementation and production costs of the identified technologies. • Within the time limitations of this project, develop the hardware or software for those techniques that show potential for technological improvement. • Prove the validity of the selected technologies/techniques to detect flaws within or verify conditions of the targeted tunnel components. • Recommend test procedures and protocols to successfully implement those techniques. Chapter 2 reports the advisory expert panel’s findings on performance criteria. According to the results reported in Chapter 3, the following techniques meet the necessary criteria to be candidate solutions: • Air-coupled ground-penetrating radar (GPR); • Thermography (handheld thermal camera); • SPACETEC scanner; • Ground-coupled GPR; • Ultrasonic tomography (UST); • Ultrasonic echo; and • Portable seismic property analyser (PSPA) ultrasonic surface waves (USW) and impact echo (IE). Each technique should be considered useful for implementation. Table ES.1 summarizes aspects of these technologies. All of these devices will require a combination of classroom and hands-on training for collecting and analysing data. But each technology also has limitations that need to be assessed. Limitations are outlined in individual appendices. Chapter 4 presents conclusions and recommendations. (Author/publisher)
Samenvatting