Untersuchungen zur Homogenität von Bauwerksteilen mit Lasertechniken

Investigations concerning homogeneity of building parts by laser techniques. The subproject B1 “Diagnostics and Quality Control by Non‐Destructive, Contactless Testing Techniques” is working within the CRC 524 on the procedural and measurement technological evolutionary development of the conventional ultrasonic through‐transmission method towards an optical measuring method by application of laser technologies. The aim is the determination of the distribution of elastic characteristic parameters for the evaluation of laboratory test specimens in investigations on durability of concrete and for the actual state of construction elements in the course of revitalising buildings. In this case, a laser induced sound excitation takes place by means of an Nd:YAG‐laser. The sound waves that have been influenced by the investigation object are detected by a laser vibrometer. By applying these methods, both a high lasing rate and a high achievable data density are to be expected since the laser beams in both systems can be deflected optically by means of scanners. Furthermore, a surveying‐technological approach for sound path determination at each pair of measuring points has been developed, which can also be used for the conventional application of the ultrasonic through‐transmission method.