Application of Impact-Echo techniques for crack detection and crack parameter estimation in concrete

Existing instruments designed for measurements involving the Impact-Echo (IE) technique are usually of limited use in field tests when investigating large concrete structures like buildings or tunnels. In 2001 demand for such instruments increased significantly particularly in Germany, as German authorities made quality control tests of state road tunnel constructions mandatory. For this task, it is essential that the equipment used for Impact-Echo measurements along profiles uses the scanning technique and is easy to work. A new concept for impact-echo testing systems is presented. The new device is small and easy to handle, robust and unproblematic regarding transportation. The system utilizes advanced impact generation, measurement, data acquisition, filtering, and visualization techniques. Regarding the software state-of-the-art requirements were implemented for both, scientific applications and field-tests. A new option is the flaw detection and estimation of crack parameters like crack width and depth out of the impact-echo signals. Some first results of in-situ measurements are shown.