New trends in the ultrasonic imaging of concrete structures by means of 3D-FMC technology

The novel technologies in ultrasound generation and data processing offer new opportunities for three-dimensional imaging of concrete structures. Especially the Full-Matrix-Capture (FMC) technique with its real-time imaging capability can be successfully utilized for quality assurance in the construction industry. Although, the available testing instruments on the market implement the principle of linear transducer array with its two-dimensional reconstruction of B-Scan images based on the Synthetic Aperture Focusing Technique (SAFT) principle. The Dry-Point-Contact (DPC) transducers utilized in commercially available instruments for concrete testing with their matrix-like layout offer a direct opportunity to implement a three-dimensional Full-Matrix-Capture (FMC) data acquisition cycle. The obtained data can be in real-time processed by 3D-TFM reconstruction and visualized and evaluated three-dimensionally. In the present contribution both state-of-the-art and novel true-3D imaging approaches and data assessment are considered on real concrete inspection objects and the advantages of enhanced data processing with respect to improved information content and easiness of result, interpretation is discussed. The article also addresses the advantages of three-dimensional data acquisition with DPC transducer systems in relation to increasing the information content of ultrasonic concrete testing and improving its detection capability. Among other things, the quantitative crack depth assessment is discussed, which provides a practical dimension through the new approach. © 2022, NDT. net GmbH and Co. KG. All rights reserved.