Tensile behavior of naturally and artificially corroded steel bars

The tensile behaviors of corroded steel bars are important in the capacity evaluation of corroded reinforced concrete structures. However, information on the tensile behaviors of naturally corroded steel bars is scarce. Moreover, differences in tensile behaviors between steel bars from natural and artificial corrosion are not well-understood. In this study, tensile testing was conducted on corroded steel bars from a residential building exposed to natural chloride attack, and from A706 corroded steel bars obtained from artificial corrosion using the impressed-current method. Based on the test results, reduction factors were proposed to relate the tensile behaviors with the corrosion mass loss for both the naturally and artificially corroded bars. Moreover, reduction factors from previous studies for both naturally and artificially corroded steel bars were collected. Comparison of reduction factors from this study and previous studies has shown that reductions factors for bars naturally corroded by chloride attack are generally larger than those by carbonation corrosion. Moreover, it is more appropriate to use the impressed-current method on bars embedded in concrete than on bare bars to simulate natural corrosion caused by chloride attack. On the other hand, reduction factors from the impressed-current method on bare bars are generally closer to those from natural carbonation corrosion than bars embedded in concrete.