Safety Evaluation of the Precast Half Deck Pannel Joints Reinforced by Connection Rebar

이음철근이 보강된 반단면 프리캐스트 판넬 이음부의 강도 안전성 평가

Abstract

The Half-depth precast deck is a structural system that utilizes pre-cast panels pre-built at the factory as formwork at the construction stage and as a major structural member at the same time after completion. These systems have joints between segments, and the detail and performance of the joints are factors that have a very large impact on the quality, such as the constructability and durability of the bridge decks. In this study, strength performance evaluation was performed for improved joints using connecting rebar by experimental method. Static loading tests were conducted on the test specimen with improved joint, those with existing joint and those without joint. The test results of the specimens were compared to each other, and the flexural strength required by the design was compared. The flexural strength required in the design was presented by finite element analysis. It has been shown that the flexural strength of the specimens with joints were more than twice that required by the design. But the flexural strength of the specimen with existing joint was about 84% of that without joint. The flexural strength of the specimen with improved joints was a nearly similar degree of that compared to the specimen without joint. And a comparison of the moment-deflection relationship curves of the two specimens also shows a very similar flexural behavior. It is confirmed that improved joint has sufficient flexural strength. In addition to strength, the bridge decks require serviceability, such as deflection and cracking, and in particular, fatigue resistance due to repetitive live loads is an important performance factor. Therefore, further verification studies are required.

Fig. 1. Moment distribution for longitudinal direction by FEM.

Fig. 2. Details of RC specimen.

Fig. 3. Details of Half-depth precast deck Specimens.

Fig. 4. Static test of the specimens.

Fig. 5. Failure of RC specimen.

Fig. 6. Failure of LBH16 specimen.

Fig. 7. Failure of LBH16H10 specimen.

Fig. 8. Moment-deflection relationship of RC specimen.

Fig. 9. Moment-deflection relationship of LBH16 specimen.

Fig. 10. Moment-deflection relationship of LBH16H10 specimen.

Fig. 11. Moment-deflection relationship of all specimens.

Fig. 12. Load-strain relationship of RC specimens.

Fig. 13. Load-strain relationship of LBH16 specimens.

Fig. 14. Load-strain relationship of LBH16H10 specimens.

Fig. 15. Load-strain relationship of the connecting rebar.

Table. 1. Summary of specimens