Automated Impact-Echo and method improvement: 2-and 3-D imaging of concrete elements

The development of advanced NDT methods for structure/infrastructure investigation and assessment is today an important topic in Civil Engineering, not only for the construction industry but also for infrastructure stock owners that could use NDT as a tool for evaluating structural safety as well as for performance criteria assessment. Point-measurement Impact-Echo (IE) has been used to investigate concrete elements and structures giving often encouraging results. Nevertheless IE data can easily lead to misinterpretation and require skilled personnel. This has been so far a limitation to a wider employ of the method. Instead, the use of scanning IE developed at BAM implements the method by giving complete and detailed information about the object under test. Furthermore an automated procedure has been developed for data collection. A description of the automated IE technique and its benefits is given, so that it is highlighted how this new approach is aimed at easing data interpretation and thus widening a reliable use of the technique in the practice. First, example laboratory applications on concrete specimens will be shown and data collection described for the plotting of 2-D and pseudo 3-D re-elaboration of the element sections. Secondly, site examples from testing railway high-speed tracks will be shown.