Experimental investigation of the relationships between residual cross-section shapes and the ductility of corroded bars

•Tension test are performed on corroded and non-corroded steel bars.•Corrosion results of natural process and then corresponds to in-situ conditions.•Corrosion strongly modify the ultimate elongation of steel bars.•Residual cross-section shape had considerable influence on the ductility of the bars.

Mechanical experiments were conducted on corroded bars that were retrieved from RC beams exposed to a chloride environment for 26 and 28 years. Three types of corrosion simulation with different residual cross-section shapes, including both uniform and non-uniform cross-section loss, were applied to non-corroded bars to investigate the influence of residual cross-section shape on the ultimate strain of the steel bars. The results showed that the residual cross-section shape and the amount of cross-section loss had considerable influence on the ductility of the bars. For the same simulated degree of corrosion, the steel bar with a symmetrically distributed residual cross-section showed the best ductility.