Mechanical damage coefficients of corroding reinforcement of an old building based on the residual “effective” area

Abstract Corrosion decreases the metal mass of the rebar, which reduces its bearing section in addition to developing the risk of hydrogen embrittlement of the bars due to the acidity created during active corrosion. To evaluate the residual strength of corroding bars, a framework was proposed in a previous paper to categorize the alternative modes of failure (ductile or brittle), emphasizing the need to calculate first what was named “the effective residual” area to further calculate tensile parameters characterizing the stress–strain curve: yield and tensile strength, modulus of elasticity, and ultimate strain. Using the effective residual area, it is possible to deduce some damage coefficients of each mechanical property by calculating the ratio of corroded/uncorroded condition and deducing if the uncorroded properties of the steel remain or have been degraded by the corrosion process. In the present paper, such an approach has been applied to bars obtained from a historical building around 100 years old. First, stress–strain tests were performed on quasi‐uncorroded and on corroded bars and thereafter, effective residual area is deduced in this case from the weight loss of the bars. With this effective residual area, we then recalculate the mechanical parameters in corrosion conditions and the corresponding damage coefficients.