Post‐fire Behaviour of Stainless Steel Rebars

Abstract Stainless steel rebars (SSR) offer significant advantages for reinforced concrete structures, especially in environments where corrosion is a major concern. Also, SSR exhibit excellent mechanical strength, high ductility, and reliable performance at elevated temperatures. However, SSR are less commonly used than carbon steel rebars (CSR) mainly due to their higher cost. This cost factor likely contributes to the limited research on the mechanical properties of SSR after exposure to high temperatures. In the present study, an experimental campaign was conducted on duplex SSR of various grades and production routes (hot‐rolled and cold‐formed) to evaluate their response following exposure to elevated temperatures. Specimens were heated to temperatures up to 1000 °C and posteriorly cooled in air to room temperature. Afterwards, specimens underwent tensile testing to obtain the residual mechanical properties, including yield strength, ultimate strength, Young's modulus, ultimate strain and strain at fracture. The residual values were compared with results obtained in similar tests conducted on CSR. Findings indicate that SSR, after cooling down, fully recover their yield and ultimate strengths and exhibit a greater residual ductility compared to CSR, even in cold‐formed specimens.