The frequency of bridge damage, such as from accidental fires during repainting and fires from tank lorry vehicle overturning accidents, has increased in Japan and in other countries. Therefore, it is necessary to make clear the influence of the strength reduction after fire. The purpose of this study is to evaluate the fatigue behavior of composite girder after fire. We carried out the fatigue test of composite girder after fire test. As a result, it was confirmed that the headed studs between steel girder and composite slab were broken at the cyclic number 780,000 when they were subjected to thermal history of 680℃ for 30 minutes.
