Die Ultraschallintegritätsprüfung für Bohrpfähle - Eine Herausforderung für die zerstörungsfreie Prüfung im Spezialtiefbau

Ultrasonic integrity testing for bored piles - A challenge for non-destructive testing

In recent years, the application of non-destructive testing in the field of special geotechnical works has grown. In particular for bored piles, clients specify ultrasonic integrity testing on a much more frequent basis.
Bored piles are executed by specialist contractors, in compliance with established technical standards. For preparation of ultrasonic integrity testing, pipes are installed on the reinforcement cage. After placement, setting and hardening of the concrete, the ultrasonic testing can be carried out. Within the last decade, Bauer Spezialtiefbau has experienced several such applications on construction sites worldwide. Key findings such as typical sources of mistakes during installation, testing, and evaluation are presented. A practical approach assists in classifying anomalies and shares responsibilities between contractual partners. It takes into account the fact that minor deviations from an absolute 'perfect product' must generally be accepted within an industrial production of bored piles in natural ground.
Quality assurance and management of the processes prior and parallel to the actual execution are to be preferred. Incoming material inspection, setting, checking and verifying limit values, detailed records and written approvals should be relied upon to a greater extent than post-construction quality control. Possible anomalies should never be assessed on the results of ultrasonic testing only.