Rating of Concrete Road Bridges With Static Proof Load Tests

Nowadays, finite element analyses provide information about the performance of a structure, but they are more or less simplified. Therefore, load tests are the only way to find the “real” behavior of an existing bridge subjected to the rating process. In this paper, the state-of-the-art concerning load tests of concrete road bridges is presented, and the problems of the execution of such tests are specified. It is pointed out that only load tests accompanied with current finite element analyses may result in a proper assessment of the level of safety of the bridge. The authors’ procedure of complex assessment of such bridges combines in-situ examination of the structure, load testing, and finite element modeling.
The paper discusses the following topics:
• Aims and fundamentals of static diagnostic and proof load tests,
• The load application method according to different codes and specifications,
• The basis for proper assessment of the target load: reliability index, partial factors approach, global rating factor approach,
• Establishing the load allowable on the bridge, based on the applied proof load,
• The proposed procedure of assessment of existing concrete road bridges by load testing.