Structural assessment of corrosion-damaged steel beams using minimum capacity curves

Assessment of the remaining capacity of corrosion-damaged steelwork is normally carried out by visual inspection, followed by full structural analysis of degraded sections. A simplified method for quantifying the initial visual inspection is proposed, using minimum capacity curves. These are derived for the remaining capacity of steel universal beams of sections currently available in the UK. The curves take account of the principal modes of failure, together with the possibility of the critical mode changing as the thicknesses of the webs and flanges reduce with corrosion. The proposed corrosion model is based on measurements of a small sample of corroded beams obtained from a chemical works. By using these curves it should be possible to avoid unnecessary closure of any plant or equipment following a negative visual appraisal of its supporting steelwork.