Tensile behaviour of corroded steel bars under different strain rates

This paper presents an experimental investigation into the tensile behaviour of corroded steel bars under different strain rates. Accelerated corrosion tests were conducted on rebars embedded in concrete by the impressed current method. The influence of corrosion and strain rates on the mechanical properties was discussed. The results showed that almost all of the corroded steel bars failed at the minimum cross-section, and the strain rate and the corrosion degree had significant influences on the yield and ultimate strengths of the steel bars. As the strain rate increased both the yield and ultimate loads increased, but strain rate effects decreased with increased corrosion degree. With increases in the average corrosion degree, the nominal yield strength, ultimate strength and ultimate strain of the steel bars decreased significantly and the yield plateau shortened or even disappeared. However, the yield strength and the ultimate strength based on the minimum cross-sectional area did not decrease, which could be attributed to the uneven distribution of the cross-sectional area along the bar. Compared with the static tensile strengths of corroded rebars, the nominal yield strength and ultimate strength under high strain rate were more influenced by the corrosion degree.