Many buildings and infrastructure elements currently reach their projected lifetime limits and require regular condition assessment in order to ensure safe subsequent using and to identify the possible need for repair or replacement. Periodic inspections as prescribed by law can not comply this task with absolute certainty, since they were not designed for the conditions in the lifetime limits.
Permanent condition monitoring is a strategy of choice to provide both need-based examination of structures and early detection of potentially dangerous defects. To this, the ability of permanent condition monitoring to reliably identify structural deviations that require further examination is crucial. Such deviations include formation and growth of cracks or corrosion damage, changes in the inclination angle or material aging. Additionally, the detection of short-term mechanical overloads may be of interest. The detection of some special types of defects is even more reliable by means of permanent monitoring, since often it‘s easier to track the change of a state than to detect the mere existence or even the location of a defect. Such condition monitoring requires nondestructive measurement devices which are constantly attached to the specimen. Nowadays, nondestructive sensors are able to detect and to track most of the mentioned damage processes long before failure.
Fraunhofer IZFP's respective R&D work is tied in its business unit "infrastructure / construction".