There are a lot of corroded steel bridges, which have to be prolonged its life in Japan. Corroded members in these bridges generally have local corrosion damages, and are often repaired by covering on the corroded area with steel plates in order to rehabilitate the strength. Recently, adhesive such as epoxy resin is often used for bonding the cover plates made of steel or CFRP, even though high-tensile bolts or welding have been adopted conventionally. In this case, surface preparation is the most important issue to bond the cover plates completely. However, complete removal of rust and wastes are quite difficult in the fieldwork of surface preparation. This paper presents recovery effect of local corrosion damage by means of covering method used by adhesive when the rust is not completely removed. Axial tensile tests were conducted for rectangular steel plates of 1,100mm x 100mm x 12mm with 400mm length of corrosion-surface-unevenness on the both surfaces, and the defects of surface preparation are made by putting tape paper at the damaged area. Then various sizes of the repair plates are bonded to consider the influence to repairing. From the test results, the ultimate strength decreased 7-10% compared with non-rust state when the defect area rate was about 30%.
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