Application of microwave 3D SAR imaging technique for evaluation of corrosion in steel rebars embedded in cement-based structures

This paper presents and discusses the attributes and results of using wideband microwave 3D SAR-based imaging technique for evaluation of reinforced cement-based structures. The technique was used to detect corrosion and thinning of reinforcing steel bars and its potential was demonstrated through experiments for different bar sizes, depth of rebar locations, and spacing between rebars. The results of a limited and preliminary investigation in which thinning of rebars with and without rust in two mortar samples were obtained at three frequency bands covering the frequency range from 8.2 GHz-26.5 GHz