## 5 Conclusions  
Recently, PC systems have been increasingly used in modular high-load long-span buildings. In particular, a one-way PC structural system that utilizes prestressed PC beams and PC slabs facilitates secure construction and economics. When constructing a one-way PC structural system, multi-tee PC slabs with dapped ends have been increasingly applied to reduce the floor height and improve structural performance and constructability. However, at the construction stage, the structural safety of the PC slabs is compromised, owing to the unanchored shear reinforcement. This study proposed the use of clip-type shear reinforcement at the dapped ends for multi-tee PC slabs. To investigate the structural performance of the multi-tee PC slabs at the construction stage, the performance characteristics of the proposed reinforcement at the dapped end, and the damage level of the insulation (expanded polystyrene) attached to the bottom of the multi-tee PC slab, a monotonic loading test was performed for simply supported PC slabs, considering the construction stage. The major test parameters were the reinforcement details of the PC slab's dapped end (Z-type or clip-type shear reinforcement) and the shear-to-span ratio (12.8 and 6.4). Based on the test, the load-displacement relationship of the multi-tee PC slab, failure mode, strength ratios to the predicted strength, and shear reinforcement strains were analyzed. The major findings of this study are summarized as follows:  
1. In the case of a general multi-tee PC slab at the construction stage, the behavior was governed by flexural failures rather than a shear failure of the dapped end or a member, owing to the slender shapes and high shear-to-span ratio;
2. The insulation material (EPS) attached to the bottom of the multi-tee PC slab was intact with the PC slab until the slab's ultimate failure without any particular damage. This indicates that the adhesion between the insulation and the PC slab could be secured until the ultimate state, as well as at the construction stage;
3. The tested-to-predicted flexural strength ratios of the PC slabs at the construction stage were 1.20-1.40. This indicates that the flexural strength can be predicted with an adequate safety margin according to the predicted equations in the current design codes. By excluding the shear contributions of the unanchored shear reinforcement (straight shear reinforcement and lattice shear reinforcement), the shear performance of the PC slab at the construction stage showed a very conservative prediction. Thus, further study is needed to determine the contribution of unanchored shear reinforcement;
4. The existing Z-type shear reinforcement at the dapped end showed limited anchorage performance, similar to that of unanchored shear reinforcement. This was because the Z-type shear reinforcement was not anchored into the concrete and had no enclosing flexural reinforcement, resulting in ineffective load transfers at the dapped end;
5. The clip-type shear reinforcement proposed in this study at the dapped end showed superior structural performance. Clip-type shear reinforcement improved the anchorage performance because of the enclosed detail and because it was arranged in the same direction as the resultant force of the tensile strut. The closer it was located to the loading point of the dapped end, the more effective the clip-type shear reinforcement was expected to be. Conceptualization, methodology, supervision, project administration, funding acquisition, and writing--review and editing, S.-M.K. ; writing--original draft preparation, investigation, validation, data curation, software, and visualization, J.-W.B. All authors have read and agreed to the published version of the manuscript. This research was financially supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (No. 2018R1A2B6007559 and No. 2019R1F1A1059249). The authors are grateful for their support. Not applicable.