Effects of high chloride contamination on direct wave of ground penetrating radar

This paper studied the effects of chloride contamination in concrete on GPR signals, which is considered as a first step to inverse GPR signal parameters to extent of chloride contamination in concrete. It was found that the travel time from the surface to the bar was delayed and the peak-to-valley amplitudes of the direct wave were attenuated. These two time domain results were further observed in joint time-frequency domain (JTFA), where the time domain waveforms were exported to generate spectrograms with short time fourier transform. Frequency spectra in the spectrograms were attenuated and shifted to the lower regimes. These chloride-driven GPR signatures warrants the possibilities of further on-going works about GPR signal inversion and ultimately, characterization of large scale chloride contamination on site.