Recently, fatigue damage accidents of orthotropic steel decks of highway bridges are increasing due to vehicles weight, traffic volume and long term usage. In this research, fatigue tests on full-size specimens of open-rib steel decks were carried out by changing the running posision with wheel running machine having a double-tire. Also, fatigue tests to verify the effectiveness of composition of steel deck with concrete were carried out after casting steel fiber reinforced concrete on the steel deck. From the former fatigue tests, different fatigue crackings were observed and the cracking mechanisms were made clear through FEM analysis. The latter test results showed a remarkable increase of fatigue durability by the composition of steel deck with concrete.
