Detection of thin layers into concrete with static and CMP measurements

Most concrete bridge decks contain a thin waterproofing layer, whose complex GPR signature can affect the detection of disorders or delaminations into the slab. In this study, we characterized the detection limits of our 2.3 GHz antenna for the detection of thin layers, with static and CMP measurements. In this last configuration, we showed that the radiation pattern and the reflection coefficient estimation are key parameters to use the inversion of the amplitude versus offset (AVO) curves for the estimation of the layer parameters. The theoretical results were compared to the results of FDTD simulations, performed with GprMax2D, and to laboratory measurements, performed on concrete slabs or sand containing thin layers.