## 5 Conclusions  
In this study, a pre-tension method using a hydraulic cylinder that can be manufactured on-site and is easy to move for repeated production, and a concrete pile used as an internal reaction force was proposed. The results of the finite element analysis performed to verify the performance of the steel-UHPC anchor block led to the following conclusions:  
* To simulate the reaction force of the steel wire anchorage according to the loading of the hydraulic cylinder, a reaction-force-type model was constructed that allowed a certain displacement by using a spring in the anchorage of the entire mono anchorage and the upper external steel wire. A maximum parallel movement of 89 mm was made in the direction of load application, and the upper surface of the fixing block moved 7.4 mm more than the lower surface, showing a slightly inclined displacement. This is considered to be a rotation caused by not matching the centroids of the three hydraulic cylinders and the centroids of the reaction forces.
* There was no bending deformation along the shear plane on the plane, but there was a slight difference in the displacement between both sides and the center in the section where the central load was applied. This shows a small value owing to the displacement according to the overall movement, but a larger value may be shown if the entire movement without tilting deformation is the same. Therefore, a re-examination with a changed load position is required.  
Figure 20: Actively yielding concrete failure/fracture for (**a**) reaction (front) side and (**b**) forcing (rear) side.  
* As described above, the contact surface of steel to concrete does not exhibit shear behavior (shear resistance at the joint surface) owing to slip; therefore, the shear force acting on the shear connection material can be neglected. However, it is better to arrange the shear connecting material evenly on the front joint surface at regular intervals for synthesis.
* The maximum stress of the steel plate was 215 MPa (compression), which occurred at the top of the outer steel wire anchorage of the fixing block; no other major deformations or stresses occurred.
* The maximum stress generated by UHPC is 92 MPa (compression), which is a problem in usability considering the material properties of UHPC assumed as linear elasticity up to 0.8 f\({}_{\text{ck}}\) (104 MPa) at 71% level for this CDP model f\({}_{\text{ck}}\) = 130. It is determined that there is no problem in pretension because damage (cracking) of the UHPC does not occur, and it is possible to reuse it.  
Conceptualization, D.-W.S.; Formal analysis, D.-W.S. and S.P.; Funding acquisition, K.-T.P.; Investigation, S.P. and Y.-W.S.; Project administration, K.-T.P.; Validation, H.-O.J. and Y.-W.S.; Writing--original draft, D.-W.S. and S.P.; Writing--review & editing, H.-O.J. and Y.-W.S. All authors have read and agreed to the published version of the manuscript.  
This study was supported by the Ministry of Science and ICT (MSIT) grant by the Korea Institute of Civil Engineering and Building Technology (KICT). (Project Number: KICT-2020102-001).  
Not applicable.  
The authors declare no conflict of interest.