FDTD Examination of Propagation Effects in GPR Wall Monitoring

The rebars in a reinforced concrete wall can be monitored using Ground Penetrating Radar (GPR) techniques. Here the influence that the corrosion or decay of the rebars has on typical GPR signals is investigated. The absorptive characteristic of oxidised rebars is seen to be detectable, particularly using polarisation sensitive sensing schemes. The influence of the aggregate used in the concrete is also examined, and in severe cases can produce significant effects in the GPR signals. This is seen to reduce the GPR sensitivity to rebar oxidation, but can show where the concrete is becoming aerated due to corrosion.