Effect of Zinc Oxide Admixture on Corrosion Inhibition of Iron in Cement Mortar Containing

Abstract

Iron plate was embedded in ordinary Portland cement mortar containing a small amount of zinc oxide powder. Sweet water and sea water were used as mixing water and steam curing was used for acceleration of corrosion for 90 days. Iron corrosion, spontaneous potential and microstructure of specimens were investigated. When the cement mortar was mixed with sea water, the iron plate was found to be vigorously corroded, and the spontaneous potential showed about -400 mv. Also, large plate-crystal s of calcium hydroxide were formed in the interfacial region between the iron plate and the cement mortar. On the other hand, with the mortar containing the zinc oxide admixture, corrosion of the iron plate did not occur, It is concluded that the use of zinc oxide as an admixture is very effective for inhibition the corrosion of iron.