Detection of accelerated reinforcement corrosion in concrete by ground penetrating radar

This paper presents a new approach to evaluate corrosion of reinforcement in concrete by ground penetrating radar (GPR). Pulse GPRs were used to monitor the continuous corrosion process in concrete, in which the changes of amplitudes, travel times and short time fourier transform (STFT) spectrograms associated with the bar reflections were continuously measured. The yearly long corrosion process of reinforcement bar was rapidly accelerated within 10 days by impressing 2A direct current across two embedded reinforcement bars serving as anode and cathode. When corrosion started, it was found that the travel times, amplitudes and the frequency spectra from the bar reflection reached a maximum or minimum, but the trends of these parameters were then reversed when the crack became wide open. The results presented in this paper will pave the way for future corrosion characterization using GPR, both in laboratory and in field.