Defect Based Condition Assessment of Steel Bridges

Steel bridges deterioration has been one of the problems in North America for the last years. Steel bridges deterioration mainly attributed to the difficult weather and environmental conditions. Steel bridges suffer mainly from fatigue cracks and Corrosion, which necessitate Frequent inspection. Visual inspection is the most common technique for steel bridges inspection but it depends on the inspector experience and conditions associated with uncertainty and subjectivity inherent in human judgments. So many NDE models have been developed use Non-destructive technologies to be more accurate, reliable and non-human dependent. Non-destructive techniques such as The Eddy Current Method, The Radiographic Method (RT), Ultra-Sonic Method (UT), Infra-red thermography and Laser technology have been used. After Reviewing the latest steel bridge NDT, it was found that the best solution is to combine two or more technology to have the most reliable Bridge evaluation. In researcher’s other publication a proposed NDE combine two method, image processing, and IR thermography. As a result of using more than one measure for inspection it was a must to develop a model which combine defects different measures and come with a unified condition rating. This paper presents systematic procedure to develop a detailed steel bridge condition assessment model by comprehensive aggregation of possible defects. Using fuzzy membership-based defect rating the proposed model will be able to translate uncertain measurements of defects into a reliable bridge condition rating.