The effect of water-cement ratio on the macrocell polarization behavior of reinforcing steel embedded in cement mortars was investigated by comparing and analyzing the macrocell polarization ratios and slopes of anodic and cathodic steels. Based on the experimental results, the relationship between macrocell potential difference and macrocell current density was also analyzed, and the mechanism of macrocell polarization affected by water-cement ratio was proposed. The results indicated that the water-cement ratios had little impact on the macrocell polarization ratios of cathode and anode. The lower water-cement ratio could reduce the macrocell current by decreasing the macrocell potential difference and increasing the macrocell polarization resistance of the cathode and anode.

The influence of nitrite concentration on the corrosion of steel immersed in three simulated pH environments containing chloride ions or sulfate ions has been investigated by comparing and analyzing the change of half-cell potential, the change of threshold level of Cl − or SO 4 2− , the change of threshold level of NO 2 − /Cl − or NO 2 − /SO 4 2− mole ratio, and the changes of anodic/cathodic polarization curves and Stern-Geary constant. The corrosivity of chloride ions against sulfate ions also has been discussed in pH 12.6, pH 10.3, and pH 8.1 environments containing 0, 0.053, and 0.2 mol/L NO 2 , respectively.

The effect of nitrite ions on the macrocell corrosion behavior of reinforcing steel embedded in cement mortar was investigated by comparing and analyzing the macrocell corrosion current, macrocell polarization ratios, and slopes of anodic and cathodic steels. Based on the experimental results, the relationship between macrocell potential difference and macrocell current density was analyzed, and the mechanism of macrocell corrosion affected by nitrite ions was proposed. The results indicated that nitrite ions had significant impact on the macrocell polarization ratios of cathode and anode. The presence of nitrite could reduce the macrocell current by decreasing the macrocell potential difference and increasing the macrocell polarization resistance of the anode.

The effect of steel surface conditions on the macro-cell polarization behavior of reinforcing steels embedded in cement mortar was investigated by comparing and analyzing the macro-cell current density and macro-cell polarization ratio of steels. The results indicated that steel surface conditions played an important role in controlling the macro-cell corrosion and polarization. The polished or pre-rusted surface had a better corrosion resistance to inhibit the flow of macro-cell current than the scaled surface that formed in the production process. Compared to the polished surface, the presence of mill scale or rust oxides on the surface of anodic steel could reduce the macro-cell polarization ratio of anode.

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