| This study is intended to examine changes in modal parameters PC box girders due to defective grouting and failures in PC tendons through a laboratory experiment. In the laboratory experiment, three PC box girders, which have different damage scenarios, are examined. Both static loading and vibration experiments were conducted. The static loading experiment was performed with 4-point bending loading, and as vibration experiment, the impact hammer test was applied. This study investigates the relationship between the energy-based bending performance adopted as a load carrying capacity, and frequencies of the PC box girders. The static loading test showed that local cracks were dominated around the location of defective grouting and failure of PC tendons, and energy-based bending performance evaluated from load-displacement curve, decreased according to loading process. Frequencies of bending modes showed a decreasing tendency but showed fluctuations as loading progresses. A moderate correlation was observed between the energy-based bending performance and the natural frequency of 1st and 2nd bending modes. |
