In order to repair and retrofit the aged metal bridge, it is important to undestand the mechanical behavior of aged steel and replacement of rivet to H.T.B. In this study, firstly, tensile loading tests, chemical tests of aged steel are conducted to understand the basic property of aged steel. Secondly, tensile loading tests for multi-bolted joint are conducted to clarify replacement of rivet to H.T.B. In this study, three specimens are fabricated and tested; all riveted joint, partially H.T.B replaced, and, fully H.T.B replaced. Based on the test results, it is found that load carrying capacity and deformability of partially and fully replaced to H.T.B can be improved due to adding frictional resistance comparing with riveted joints only.
