Effect of Water-Cement Ratio on the Macrocell Polarization Behavior of Reinforcing Steel

Abstract

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.

Effect of Nitrite Inhibitor on the Macrocell Corrosion Behavior of Reinforcing Steel

“…The exposed area of the steel was 59.7 cm 2 . The surface of the exposed area was polished by sandpaper number 180 and cleaned with acetone just prior to being placed in the mold so as to ensure the accuracy of the experimental results [21,22].…”

“…For some conditions, this effect could be significant, notably when the resistance of the concrete or mortar was too high to support the macrocell activity. For this reason, the specimens in Aside and B-side were partially immersed in water to enhance the electroconductivity of mortar [21,22].…”

“…of Cathode and Anode. In the macrocell corrosion state, it was important to know the relative contributions from the polarization of the cathode, anode, and the mortar resistance, as described by Δ corr 1 = Δ corr 2 + Δ corr 3 + Δ corr 4, which had been graphically illustrated previously [22]. In order to obtain the relative contributions of Δ corr ( = 2, 3, 4) on Δ corr 1 for the cases with various nitrite concentrations, the relationships between Δ corr 1 and Δ corr ( = 2, 3, 4) were plotted in Figure 7 and were fitted by the linear function.…”

“…The value of the point that represented the corrosion state of cathodic (anodic) steel in microcell corrosion state was obtained by averaging the halfcell potential and the microcell current density obtained in the disconnected periods, while the value of the point that represented the corrosion state of cathodic (anodic) steel in macrocell corrosion state was obtained by averaging the halfcell potential and the macrocell current density obtained in the connected periods. The macrocell polarization slopes of cathode ( ma-c ) and anode ( ma-a ) could reflect the polarization ability of cathode and anode in the macrocell corrosion state [22]. The higher the ma-c , the stronger the ability of the cathode to receive the electrons, which results in a lower macrocell polarization resistance of the cathode.…”

Effects of Mineral Admixtures on Macrocell Corrosion Behaviors of Steel Bars in Chloride-Contaminated Concrete

“…Additionally, known from the previous studies [7][8][9][10], the macrocell corrosion rate and control mode are mainly determined by half-cell potential and microcell current density of cathodic and anodic steels, macrocell potential difference between cathodic and anodic steels, macrocell polarization slopes, and macrocell polarization ratios of cathodic and anodic steels. The use of mineral admixtures in marine reinforced concrete structure would have an effect on these above parameters.…”