Corrosion behavior of steel reinforcement bars embedded in concrete with sugar cane bagasse ash

The corrosion behaviour of G42 steel reinforcing bars embedded in modified concrete was studied, using cylindrical concrete specimens with sugar cane bagasse ash (SCBA) as partial replacement for Portland cement at proportions of 0, 15, 30 and 45 wt%. The specimens were exposed to a brine environment using the impressed current technique during 0, 8, 16, 32 and 64 h, in order to accelerate the corrosion. Behaviour of the corrosion process was evaluated by means of electrochemical measurements using the Electrochemical Impedance Spectroscopy technique (EIS). The results showed an impedance reduction in concrete after impressed current exposure in all tested formulations. Lower reaction rates were observed in specimens with 0 and 15 wt% of SCBA content after 64 hours of accelerated corrosion. The impedance spectra of the samples with 45 wt% of SCBA content were compared with an equivalent circuit model, where high corrosion damage was observed.

Keywords: Accelerated corrosion, Electrochemical Impedance Spectroscopy, Sugar cane bagasse ash, Impressed current, X-ray photoelectron spectroscopy.