ABSTRACT
Transportation system in China has great developed since 1980s, and lots of highway bridges have been constructed in recent 30 years, in which more than 90% of these constructed bridge are concrete bridge. These in-service concrete girder bridges are carrying increasing traffic volume and heavier traffic loads (Li et al. 2010, Wang et al. 2012.). The bridge management departments are paying more attention to bridge safety, durability and remaining service life. During the bridge life cycle including design stage, construction stage, service stage, there are many factors that affect the performance of the bridge. Meanwhile, under the loading condition and service environment, the resistance of bridge structure is decreasing gradually. Besides, overloading and other occasional events would accelerate degradation processes of structural resistance. And the fatigue resistance degradation of the bridge is a very important factor among many factors (Rliem Committee 1984, Herwig 2008).
Because of these problems, scientific and effective strengthening ways for concrete bridge can be rationally used to recover and improve the structural capacity while service life can also be extended in the same time (Shi et al. 2003). However, it may not always be satisfactory when improper reinforcement was taken.
Therefore, performance detection and assessment work become particularly important for concrete bridge, especially after strengthening. Nowadays, the popular bridge inspection methods mainly include appearance inspection, load test, and monitoring during operation period. Bridge performance assessment system can be established through these existing testing methods. A concrete box girder bridge was taken as a case study for performance assessment. Based on the static and dynamic test data, the structural capacity and remaining fatigue life were calculated, and the strengthen effectiveness was assessed by evaluating performance.
