Polarization-Dependent Ground-Penetrating Radar Assessment of Reinforcement Corrosion

The aim of this paper was to assess the effect of ground-penetrating radar (GPR) wave polarization on the detection of reinforcement corrosion in concrete structures and to analyze the feasibility of improving the sound/corroded separation by fusion of selected signal parameters. The amplitude and propagation time of the surface wave and the wave reflected from the reinforcement were studied in two orthogonal polarizations: parallel (L) and perpendicular (T) to the rebar axis. The obtained results showed that, regardless of polarization, all time parameters increased with corrosion progression. Corrosion-related amplitude changes were different: a decrease was observed in the L polarization, while an increase was observed in the T polarization. Statistical analysis indicated that time parameters were the most effective in detecting corrosion, while surface wave amplitude was the least sensitive indicator of degradation. Furthermore, it was shown that data fusion in a single polarization led to only a moderate improvement in the separation ability of GPR parameters. This work demonstrates for the first time that fusion of parameters (especially time) from two orthogonal GPR polarizations significantly improves the separation ability of sound and corroded samples, indicating the complementary nature of data from both polarization configurations.