C_3H_7NO_2S Effect on Concrete Steel-Rebar Corrosion in 0.5 M H_2SO_4 Simulating Industrial/Microbial Environment

摘要

This paper investigates C_3H_7NO_2S (Cysteine) effect on the inhibition of reinforcing steel corrosion in concrete immersed in 0.5 M H_2SO_4, for simulating industrial/microbial environment. Different C_3H_7NO_2S concentrations were admixed, in duplicates, in steel-reinforced concrete samples that were partially immersed in the acidic sulphate environment. Electrochemical monitoring techniques of open circuit potential, as per ASTM C876-91 R99, and corrosion rate, by linear polarization resistance, were then employed for studying anticorrosion effect in steel-reinforced concrete samples by the organic hydrocarbon admixture. Analyses of electrochemical test-data followed ASTM G16-95 R04 prescriptions including probability distribution modeling with significant testing by Kolmogorov-Smirnov and student's t-tests statistics. Results established that all datasets of corrosion potential distributed like the Normal, the Gumbel and the Weibull distributions but that only the Weibull model described all the corrosion rate datasets in the study, as per the Kolmogorov-Smirnov test-statistics. Results of the student's t-test showed that differences of corrosion test-data between duplicated samples with the same C_3H_7NO_2S concentrations were not statistically significant. These results indicated that 0.06878 M C_3H_7NO_2S exhibited optimal inhibition efficiency η = 90.52±1.29% on reinforcing steel corrosion in the concrete samples immersed in 0.5 M H_2SO_4, simulating industrial/microbial service-environment.