Kuala Lumpur 2004 ACCEPTANCE CRITERIA FOR BORED PILES BY ULTRASONIC TESTING

Ultrasonic testing, or crosshole logging (CSL), has become the primary means for judging the integrity of bored piles and barrettes. While the test procedure is now well standardized, interpretation of the results is still controversial. The following paper reviews a number of published criteria, and then goes on to evaluate the various sources of measurement error: Concrete variability, access tube effect, FAT picking error, sampling error and hardening time effect. It is shown that in certain cases, especially in smaller diameter piles, potential error may exceed some established acceptance criteria. The paper describes two methods for accurate determination of wave velocity, and suggests themes for further study