EIS study on corrosion evolution of chemical quenched rebar in concrete contaminated with chloride

The corrosion evolution of scaled rebar cooled by a chemical reagent FM in concrete immersed in 3·5%NaCl aqueous solution was studied by electrochemical impedance spectra and compared with bare rebar. The results show that the corrosion evolution process of FM cooled rebar consists of three stages during the immersion: the passive stage, the accelerated corrosion stage dominated through the charge transfer step and the steady corrosion stage dominated through the mass transfer step. The corrosion rate of FM cooled rebar reaches a steady rate (<0·7 μA cm⁻²) after 80 days. However, the corrosion rate of bare rebar always increases at all immersion times. After immersion for ∼1 year, the corrosion rate of bare rebar is nine times larger of that of FM cooled rebar. Therefore, the corrosion resistance of the rebar has been improved significantly by applying the FM cooling process.