Ultrasonic Crosshole Test

It’s a technique based on the principles of ultrasonic pulse velocity test for deep foundations. It provides a high resolution exploration that allows to get information regarding possible defects and variations in the quality of the concrete of the tested element.
 
For this test a number of access tubes must be installed inside the reinforcement cage before pouring concrete. Then, pairs of transducers are lowered in the tubes and measurements are taken at multiple depths with the transducers placed in different access tubes. The measurements consist in the identification of the arrival times of longitudinal waves which are used to compute the velocity of the ultrasonic pulse traveling through the element.

High velocities imply a high quality concrete, while low velocities indicate a lower quality or other anomalies such as honeycombed concrete, voids, etc.

Typical field setup, 2D and 3D results, where an anomaly is present.