Comparison of Five Standards on Ultrasonic Pulse Velocity Testing of Concrete

The essence of the pulse velocity method is that the transition time of an ultrasonic longitudinal pulse (wave) is measured in concrete. From this, the pulse velocity can be calculated, and inferences are drawn concerning the strength or overall quality, or both, of the concrete. Many countries have standardized this procedure, five of which are compared in this paper. These are American (ASTM), British (BS), German (DIN), Russian (GOST), and Slovak (STN) standards. The best, and perhaps the only reliable applications of the ultrasonic pulse velocity are for checking the uniformity of concrete and monitoring the changes in a concrete with time. Strength estimation is possible with only ±20% accuracy and even this can be achieved only under strict laboratory conditions. The other applications (defect detection, crack depth measurements, and so forth) are even less reliable. Thus, they are inadequate for practical purposes, especially under field conditions. No warning is given in any of the examined standards about the unreliability of most of these applications. It is hoped that an evaluation of these standards will help in the better use of the ultrasonic pulse velocity method and contribute to the improvement of future standards.