Determination of residual cross-sectional areas of corroded bars in reinforced concrete structures using easy-to-measure variables

Area loss of corroded rebar cross sections is a crucial variable that is difficult to measure. In this paper, virtual models of corroded bars were built using 3D laser scanning technology; and, 693 severely corroded sections were screened to explore a practical way for the area loss determination. The results show that residual sections can be simplified into ellipses for general corrosion; otherwise, it can be ascribed to combined pit and general corrosion. Four spot penetration depths were taken as independent variables which can be easily measured. Based on the variables, regression models were developed and proven to be effective.