# Evaluation of Horizontal Shear Performance of Composite Girders Using Separable Shear Connectors
## 5 Conclusions  
This study introduced a novel embedded separable shear connector to streamline the removal and replacement of aged or damaged decks of composite bridges with girders and decks. The efficacy of this method and that of the conventional rebar shear connector approach was assessed using horizontal shear tests. The results were evaluated against various design standards. Flexural tests on the composite girders provided key insights, leading to the following conclusions. 1. In horizontal shear tests, compared with the rebar specimens using conventional rebar shear connectors, the detachable shear connector model M-DY specimens exhibited performance differences at the 1% level, whereas S-DY specimens exhibited approximately 10% lower shear-strength performance. This phenomenon could be attributed to pull-out failure occurring because the embedded depth of the detachable shear connectors was not sufficiently secured. In the flexural performance test, this was improved by drilling through-holes in the embedded anchor nut of the S-DY shear connector and connecting rebar to resist pull-out. Consequently, pull-out did not occur when applying the improved method to PSC composite girder specimens. 2. In terms of slip displacement, DY specimens exhibited 55% lower results compared with rebar specimens. However, although DY specimens exhibited less slip than rebar specimens, where larger slip occurred due to pull-out failure from insufficient embedding depth and anchorage, both exceeded 6 mm, satisfying the ductility design conditions of EN standards. 3. From the simulation test results of deck disassembly and reconstruction using DY shear connectors, the horizontal shear strength of the disassembled and reconstructed  
Figure 16: Force–slip curves. (**a**) Rebar_F; (**b**) DY_F; (**c**) DY_H. specimens was approximately 97.7% of the average horizontal shear strength of regular specimens (S-DY), indicating that sufficient horizontal shear strength was secured. 4. Most M-DY and S-DY specimens with demountable shear connectors satisfied the shear-strength requirements of the AASHTO LRFD, ACI-318, and KDS standards, with the exception of the EC2 standard. 5. According to the flexural test results of PSC girders with DY shear connectors and composite girders of precast decks, the horizontal shear strength was approximately 4% higher compared with conventional rebar shear connector specimens, demonstrating superior performance over conventional rebar shear connectors. In particular, because the DY_F specimen used 35.1% fewer shear connectors compared with the Rebar_F specimen, the detachable shear connectors are approximately 60% more effective than conventional rebar shear connectors are. These findings reveal that the newly developed separable shear connector facilitates the replacement of damaged or aged decks without damaging existing girders, simply by detaching the shear connectors to accommodate new deck installations. Moreover, the connector demonstrated equal or superior shear-strength performance compared with conventional rebar shear connectors, affirming its effectiveness and potential as a viable alternative. This capability should be particularly beneficial for removing and replacing aged decks, thereby enhancing the efficiency and sustainability of bridge maintenance practices. Conceptualization, [PERSON]-S.J. ; Methodology and analysis, [PERSON]-H.P. and [PERSON]-[PERSON]; Experiments and investigation, [PERSON]-[PERSON] and [PERSON]-[PERSON]; Writing-original draft preparation, [PERSON]-S.J. and S.-H.P. ; Writing-review and editing, [PERSON]-S.J. and C.-Y.K. ; Visualization, [PERSON]-S.J. and S.-H.P. ; Supervision, [PERSON]-Y.K. All authors have read and agreed to the published version of the manuscript. This work was supported by the Korea Agency for Infrastructure Technology Advancement (KAIA) grant funded by the Ministry of Land, Infrastructure, and Transport (Grant No.