This paper describes application of nondestructive test (NDT) methods for condition assessment of metal-tensioned elements in geotechnical engineering applications including rock bolts, ground anchors and soil nails. Electrochemical tests, such as measurements of half-cell potential and polarization, are used to detect the presence of corrosion and evaluate the integrity of corrosion protection systems. Mechanical wave propagation techniques, such as impact and ultrasonic tests, are used to locate features along the length of an element including loss of cross section from corrosion. Interpretation of test results requires knowledge of the electrical
continuity between elements being tested, and knowledge of the details associated with the installation of the system being evaluated.