# Tension Performance of Precast Bridge Deck Longitudinal Joints with Different Configurations
## 5 Conclusions  
In this study, a tension load was applied to a series of precast bridge deck longitudinal joint specimens to determine the influences of the joint width, rebar type, and steel plate. These influences were evaluated to obtain an optimal joint configuration. Finally, a finite element analysis was conducted, and its similarity to the behavior observed in the tests was verified. The results of this study are as follows:  
1. When the width of the precast bridge deck joint using hooked rebars and a steel plate was 100 mm (J100-HB-SP), the initial cracking load was 20% higher, and the final load was 18% higher than when the width of the same joint configuration was 150 mm (J150-HB-SP). Therefore, the joint width should be set to 100 mm to ensure that the precast bridge deck joint has high initial cracking and final loads.
2. The use of hooked rebars and a steel plate in a 100 mm wide precast bridge deck joint (J100-HB-SP) resulted in a 61% higher initial cracking load than when no rebars were provided in an otherwise equivalent joint (J100-NB-SP). Thus, steel rebars are required to prevent precast bridge deck joints from cracking at low loads.
3. Although their behaviors were otherwise similar, the final relative displacement of the precast bridge deck joint was larger when using looped rebars and no steel plate (J0-LB-NP) than when using hooked rebars and a steel plate (J100-HB-SP).
4. Similar precast bridge deck joint behaviors were observed when using looped rebars and a steel plate (J0-LB-SP) or hooked rebars and a steel plate (J100-HB-SP), but the final relative displacement of the latter was 38% smaller, owing to the limited connectivity provided by looped rebars. Therefore, hooked rebars should be used to ensure joint connectivity.
5. The overall structural performance of the optimal precast bridge deck joint (J100-HB-SP) was similar to that of an equivalent monolithic CIP bridge deck (C-SB-NP), indicating that J100-HB-SP is a suitable configuration for a precast bridge deck longitudinal joint.
6. The final crack geometry of J100-HB-SP was similar to the final crack geometry observed using a high-speed PCIe camera. In addition, since diagonal cracks did not occur until the final load of 800 kN, the structural behavior of J100-HB-SP can be confirmed as safe.
7. The load-relative displacement curve and overall crack pattern obtained using the FEM were similar to those observed during the test, and the final relative displacements were within 2%. Therefore, the proposed FEM was able to accurately predict the structural behavior of the precast bridge deck longitudinal joint.  
Figure 14: Comparison of load–relative displacement curves from the test and FEM analysis results of J100-HB-SP.  
The gap between the appropriate longitudinal connections on the bridge deck was 100 mm, and the joint between the installed hook reinforcement and steel plate showed the most optimal longitudinal behavior.  
Conceptualization, S.C.; formal analysis, H.N.; investigation, J.H.; data curation, J.H.; writing--original draft preparation, H.L.; writing--reviewing and editing, S.K. and H.L. All authors have read and agreed to the published version of the manuscript.  
This research was supported by a grant (No. 21 TBIP-C160991-01) from the Technology Business Innovation Program funded by the Ministry of Land, Infrastructure and Transport of the Korean government.  
Not applicable.  
No new data were created or analyzed in this study. Data sharing is not applicable to this article.  
The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.