## 1 Introduction
### Basic Concept of the Experimental Program
#### 2.1.2 Test Specim with Unreinforced Joints in the Webs (TS\({}_{\text{Point}}\))  
In contrast to the reference girder described above, this test specimen had unreinforced joints in the webs, representing the bridge superstructure of the presented bridge construction method. Compared to the actual bridge superstructure, the following simplifications--in addition to the ones described in the Introduction--were made for the test program: Instead of producing an in situ concrete layer on the bottom and top slabs and placing the continuous longitudinal reinforcement there, it was decided to produce the bottom and top slabs as a whole in one pour. Compared to the real bridge superstructure, the reinforcement in the vertical position could thus be laid somewhat closer to the outer edge of the concrete, while the horizontal distance to the corner remained consistent. The test specimen was designed with the same amount of continuous longitudinal reinforcement as the reference beam. As the longitudinal reinforcement of the webs should not be effective due to the joints in the webs as torsional reinforcement, an equivalent amount of additional longitudinal reinforcement was placed in the bottom and top slabs. This meant that, in addition to the \(\mathcal{O}8/150\) of the reference girder, two \(\mathcal{O}12\) bars were placed in each corner of the deck and bottom slabs. The position of this additional reinforcement was chosen to be as close as possible to the edge of the corners. In the actual bridge superstructure with in situ concrete layers, this would be the case for the bottom slab (apart  
Figure 3: Construction process of the test specimen serving as the reference girder (TS\({}_{\text{Ref}}\)): (**a**) reinforcement of the 9.20 m long webs and parts of the middle diaphragm before casting; (**b**) reinforcement of the 9.20 m long bottom slab between the webs before casting; (**c**) casting of the deck slab and the diaphragm in the middle of the girder; (**d**) completed test specimen. from the abovementioned vertical distance). The total area of continuous longitudinal reinforcement in this girder, with 10 \(\mathcal{O}\)8 mm and 8 \(\mathcal{O}\)12 mm (total 14.074 cm\({}^{2}\)), was equal to that of the reference specimen with 28 \(\mathcal{O}\)8 mm. The production process of the specimen with joints (Figure 4) was essentially the same as for the reference beam, with the only difference being that the webs were not produced in one step. Instead, each web was divided into two partial plates, which were concreted separately (Figure 4a depicts the unreinforced joints between the webs). At the ends of the slabs, where the joints were to be created, shear keys--based on [7]--with a depth of 5 mm and a height of 30 mm were placed over the entire height of the web (Figure 2b). The sections with a length of 4.475 m were then moved to a vertical position, with a 0.25 m gap left between them for the middle diaphragm, representing the pier segment. As previously described, the unreinforced vertical shear joints in the webs were located at the transition between the webs and the middle diaphragm, as would be the case with a pier segment and the hollow box girder in the novel bridge construction method. In contrast to the joints studied by [PERSON] et al. [7], no special mortar was used for filling the joints, as the concrete of the diaphragm itself served this purpose. Before the diaphragm was cast, the entire bottom slab with a length of 9.20 m was concreted between the webs (Figure 4b shows the reinforcement of the bottom slab and middle diaphragm, as well as the joint). Afterwards, the middle diaphragm was cast together with the deck slab in one step (Figure 4c shows the reinforcement before casting). As was the case for the reference girder, concreting of the outer diaphragms was carried out subsequently, at a distance of 4.00 m from the center of the girder, using a fast-setting grout. Figure 4d shows the final test specimen.