Advanced NDT Contributing Performance Evaluation of Civil Structures

Through the life cycle of civil infrastructures, quality assessments shall be implemented during construction, in-service, before/after repair and so forth; however, there are no decisive techniques to evaluate the inside of structures non-destructively. The authors have developed an advanced measurement method using a tomographic approach referred to as AE tomography without artificial excitations, leading to one-side access evaluation of large infrastructures. With this advanced technology, internal damage or defects can be visualized as a distribution of elastic wave parameters such as velocities so that damage identification consisting of locations and damage degree would be possible. In the paper, qualities of infrastructures in the consecutive phases of the life cycle are assessed with these tomographic approaches and the estimated damage is quantified with actual damage observation.