Relationship between corrosion and element severity score for reinforced concrete beams

Guidance for highway bridge and structure maintenance management in the UK is provided by the code of practice (CoP) 'Management of Highway Structures'. With regards to inspection of reinforced concrete beams in accordance with the code, the professional judgement of the bridge engineer is required to assess the extent and severity of deterioration with help from a library of different defects. The Extent of the defects is rated A – E whilst the Severity is scored 1 – 5, giving an Extent and Severity score for each element, known as the element condition score. However, the Code does not provide information on the corresponding levels of corrosion in the steel reinforcement in the damaged beam. The purpose of this paper is to relate the element severity scores for a range of damaged reinforced concrete beams to approximate levels of corrosion of the main steel, thereby giving the bridge inspector an understanding of the seriousness of corrosion for each of the five Severity scores.