Title: Quantitative Relationship Involving Reinforcing Bar Corrosion and Ground-Penetrating Radar Amplitude

Author(s): Rakesh K. Raju, Md Istiaque Hasan, and Nur Yazdani

Publication: Materials Journal

Volume: 115

Issue: 3

Appears on pages(s): 449-457

Keywords: amplitude; dielectric constant; durability; ground-penetrating radar (GPR); reinforcing bar corrosion; two-way travel time

DOI: 10.14359/51702187

Date: 5/1/2018

Abstract:
Ground-penetrating radar (GPR) has been used for qualitative assessment of defects in reinforced concrete structures, such as corrosion-induced deterioration in concrete bridges. However, reliable quantitative models for GPR estimations of reinforcing bar corrosion are unavailable. This study quantitatively related the reinforcing bar corrosion with the maximum reflected waveform amplitude from GPR scanning. Accelerated corrosion was used to induce reinforcing bar corrosion, and GPR scanning monitored corrosion at three stages: before and after submersion into saltwater solution and at the end of a preset corrosion period. As expected, the reinforcing bar corrosion mass loss was greater for longer corrosion periods, larger reinforcing bar size, and lower cover. The GPR amplitude increased with increased corrosion activity. A set of polynomial curves were proposed for particular dielectric constant, reinforcing bar size and cover. The model was calibrated with the GPR scan data from a portion of a demolished old concrete bridge deck.