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The Effect of Inhomogeneity of Concrete Quality in Corrosion of Reinforcement

This paper presents the laboratory results of the effect of inhomogencity of concrete quality in initiation period of corrosion and rate of corrosion of reinforcement. Two types of reinforced concrete including columns and slabs were investigated. Each specimen was made of two different concrete qualities by changing water-cement ratio. Specimens were subject to a series of laboratory tests, including corrosion potential, rate of corrosion and resistivity. The resuts showed that inhomogeneity of concrete quality is an important factor in reducing of initiation time of corrosion and increasing rate of corrosion. Direction of reinforcement and direction of pouring concrete are important parameters, which have effects on potential differences in two parts of the reinforced concrete members. In other words, duration of initiation corrosion was less in columns compared to that of slabs, due to differences in direction of reinforcement.