Original Articles: 2015 Vol: 7 Issue: 10
Effect of Vernonia amygdalina extract and zinc oxide inhibitor on the corrosion of mild steel reinforcement in concrete in 0.2M H2SO4 Environment
Abstract
The effect of Vernonia Amygdalina- VA(bitter leaf) extract and zinc oxide (ZnO) inhibitors on the corr osion behaviour of embedded steel rebar in concrete immer sed in 0.2% H 2 SO 4 was investigated by potential measurement, pH and gravimetric methods using the inhibitor conc entrations of 25, 50, 75, and 100%. The results wer e further analysed using the two-factor ANOVA test. Potential measurements were performed using a digital voltme ter and a copper sulphate reference electrode. Compressive st rength of each block sample was determined after th e experiments. Weight loss values were obtained from the gravimetric method, and the inhibitors’ efficie ncy was computed from the corrosion rate of each of the tes ted samples. Both inhibitors gave appreciable corro sion inhibition of the embedded steel rebar at 25 and 50 % concentrations. ANOVA test confirmed the results at 95% confidence. VA’s concentration had greater effect o n potential and pH; ZnO showed great significance i n potential measurements only.