The mechanical properties of reinforcing bar is known to affect the ultimate state of reinforced concrete structures. This study investigates how chloride-induced corrosion of rebar affects its elongation characteristics. With a view to establishing a practical assessment method for residual performance of existing RC structures, this study has employed a method of estimating the strength and elongation characteristics of rebar using only a vernier caliper. The results of this study can be summarized as follows; Residual sectional area of corroded rebar can be estimated by measuring the residual diameter of rebar. Elongation capacity reduces to 20percent with the residual area of rebar being in a range of 70 to 80percent. The stress-strain relationship and failure strain of corroded rebar can be estimated based on the stress-strain relationship of sound rebar and the smallest sectional area of corroded rebar.
