Abstract
About 50,000 steel railway bridges are in service. More than half of them have been in service over their design lifetime. Some of these bridges have problems such as corrosion and fatigue. To improve the performances of the existing bridges without replacement of them, we proposed a method to install concrete decks on the existing steel girders. By this method, the structural system of the bridge can be changed into composite girder. To realize this technique, it is necessary to apply pre-cast concrete decks in order to enable short-time installation work. To install the pre-cast decks, connection by filler mortar is possible to be applied. Then, it is necessary to clarify the strength of the girder-deck connection and deck-deck connection using filler mortar.
In this study, loading tests of composite girder that was fabricated using proposed method were carried out in order to evaluate the structural performance of the girder and to observe failure mode of the connection. As a result, it was found that the bending stiffness and the yielding capacity of the girder were improved comparing with steel girders. At the girder-deck connection, the failure occurred at the steel-mortar interface at the girder end. Finally, we obtained shear strength of the girder-deck connection and it was found that the proposed method is applicable to actual railway steel bridges without failure of the girder-deck connection.
