Post‐fire Residual Strength and Ductility of Structural Steels from Hollow Sections

Abstract Steel structures are severely affected by the extreme temperatures reached during a fire. After this, if structure has not collapsed, remaining elements can be reused they excessively distorted or material is still fit for service. In last case, residual properties of steel must adequate and fulfil requirements current standards. On this matter, it hypothesized that behaviour only depends on highest temperature fire episode, but also load was simultaneously bearing. This work focused an experimental study post‐fire structural steels. Specimens were cut from (S355) cold‐formed circular hollow sections (CHS) subjected to combination tensile stress high temperature. Afterwards, specimens cooled in air back room and, finally, increased until specimen failure. The obtained results allowed discussing yield strength, ultimate strength stiffness steel, special focus put ductility. provide basis appraisal after fire, supporting further decision its reinstatement subsequent demolition.