The application of selected tomographic imaging methods in the inspection of concrete bridges

Majority of non-destructive testing (NDT) methodologies necessitate access to only one side of the structure. Due to factors such as wave absorption or reflection by the test object, it is necessary to position the transmitter and receiver on different sides of the test surface. This particular investigative modality is designated as tomography. The article reviews the literature on the use of tomography for the inspection of concrete structures, and presents the results of research conducted on the use of GPR in tomographic mode on a bridge support. It is concluded that GPR in tomographic mode is well suited for mapping larger areas with varying concrete quality. Conversely, radiography is particularly well suited to point measurements and is not limited by the influence of dense reinforcement mesh. It has been determined that when employing a suitable radiation source, the risk to human health when utilising this method is negligible. The article examines X-ray tomography and ground-penetrating radar (GPR) techniques, both employing tomographic imaging and requiring access to at least two sides of the structure. It aims to compare the two methods in terms of accuracy and data acquisition, based on the author’s experimental results and evidence from international literature.