Can be GPR technique useful for strength characterization of concrete?

The possibility of material characterization through the GPR measurements, taking into account the integration with the ultrasonic technique, has been studied and possible relationships between the permittivity of materials and their bulk density are discussed. We present here two different approaches. The first one describes an attempt to correlate the mechanical strength of concrete (as well the ultrasonic velocity) with the permittivity of the material. A series of samples of concrete, characterized by different material properties, were used for georadar and ultrasonic measures, seeking correlations among experimental data. The second approach illustrates the comparison between GPR and ultrasonic techniques to detect anomalies within the concrete. A 3D tomography was performed with ultrasonic and GPR measures on a laboratory model and the data obtained are here compared.