CRACK DETECTION AT CONCRETE CONSTRUCTION UNITS FROM PHOTOGRAMMETRIC DATA USING IMAGE PROCESSING PROCEDURES

Cracks on the surface of a concrete construction are measured and evaluated by a digital photogrammetric method. Knowing these cracks, the behaviour of the construction, especially using textile reinforcement, can be interpreted. In the photogrammetric data the cracks are extracted by analysing the deformations. Two options are presented. On the one hand cracks are detected by searching for the maximum of strain and are followed using a list of rules. On the other hand the non-cracked areas between the cracks, which are characterized by small strains and uniform motions, are selected by a dynamic active contour method. The project "photogrammetric measurement" is part of a collaborative research centre "textile reinforced concrete foundation of a new technology" at the RWTH Aachen University. * Corresponding author