Radar tomography for evaluation of reinforced concrete structures

Radar tomography is a non-destructive technique that can be applied to concrete structure to map internal inhomogeneities, defects or property variations (moisture, chlorides concentration, density, steel fiber distribution). The method is illustrated by presenting the physical principles and the procedure for performing the experiments, i.e., the required equipment, the acquisition methods and the processing algorithms. Resolution, possible artefacts and criteria for interpreting the results are discussed to introduce the reader to a correct use of the technique. A few examples are also illustrated to show possible results. Advanced algorithms such as full-waveform inversion or diffraction tomography are briefly introduced and references are given to more in-depth studies.