Electrochemical impedance behavior of concrete containing natural zeolite and copper slag

The current study assesses the electrochemical impedance behavior of binary and ternary concrete mixtures containing natural zeolite and copper slag as supplementary cementitious materials (SCMs). To this aim, several mixtures were made by replacing up to 30% by weight of Portland cement with natural zeolite or a combination of natural zeolite and copper slag. A test setup was made and suitable equivalent circuits were used to measure the electrochemical behavior of reinforced concrete specimens. Strength and transport properties of these mixtures were also measured. The results of this study revealed considerable improvement in the polarization resistance of steel–concrete interface and corrosion rate of reinforcement by use of natural zeolite and copper slag. The corrosion rate was reduced by almost 65% when 30% of Portland cement was replaced with supplementary cementitious materials. Transport properties were also improved by inclusion of SCMs.