## 2 Proposed Test Setup
### Alternative Test Setup for the Identification of Bond Properties  
For the present experimental campaign, unreinforced concrete slabs of sizes \(300\times 300\times 150\) mm were cast. The threaded bars used for the system were M12 class 12.9, which required a borehole diameter of 14 mm. In order to be able to control the test with the adhesive anchor unloaded end, a hole needs to be drilled through the concrete specimen. In general, during the hammer-drilling procedure, the concrete toward the other end fails with a concrete breakout of unknown geometry. Such breakout needs to be avoided or controlled in order to ensure the repeatability of the tests. One of the methods which can be used to control the concrete breakout is to force it consistently to localise on a notch. In order to create such a notch, a wooden cylinder of dimensions \(35\times 40\) mm was placed in each one of the moulds before the concrete casting, creating a cylindrical void after demoulding. The concrete breakout localises at this void during the hammer drilling (see Figure 4a). Once the hole is drilled and properly cleaned, the lower end of the borehole needs to be sealed in order to avoid leakage of adhesive mortar during the anchor installation (see Figure 4b). Additionally, plastilin is placed in the notch to facilitate the removal of the excessive adhesive mortar that would otherwise fill the notch. After the hole is sealed, the anchor is installed and left to cure for the required time according to the manufacturer product installation instruction. Once the adhesive mortar hardens, the lower part of the slab is cleaned from the excessive adhesive mortar (see Figure 4c) in order to expose the threaded bar's unloaded end. A specially designed LVDT holder is coupled with the lower end of the threaded bar, which was previously milled to obtain a precise sliding coupling with the holder and to minimise the bond with the mortar. This procedure was chosen to measure the lower end displacement along the same axes of the threaded bar. The holder is then fastened in the correct position with a rapid-hardening adhesive mortar. A thin layer of plastilin is introduced to isolate the two adhesive mortars from each other (see Figure 4d). The applied testing speed was 0.001 mm/s for all tests. Figure 5 shows the experimental setup used for the testing. The specimen is positioned on a wooden platform that allows access to the unloaded end of the anchor, in order to setup the displacement transducer. The anchor displacement was measured at the loaded end and at the machine stroke, and measured and controlled at the anchor's unloaded  
Figure 4: Specim preparation process. end. At the unloaded end, a single LVDT was used, while at the loaded end, three LVDTs were placed in a 120\({}^{\circ}\) configuration to record the pull-out displacement at 60 mm from the concrete surface. A cardan joint is used to connect the specimen to the machine in order remove moments. The two beams that hold the supporting plate are connected with spherical couplers to threaded bars, which are themselves connected to the base of the machine. Three configurations of debonding methods and support geometry were tested in this experimental campaign, as shown in Figure 6. Additionally, two configurations were used as controls. In the first one (see Figure 6a), in order to unbond the threaded bar from the concrete, a 30 mm portion of threaded bar close to the concrete surface was wrapped with paper tape and Teflon tape. This configuration is referred to as Teflon. The paper tape was used to create a smooth surface over the ribs of the threaded bar, while the Teflon tape was used for its poor adhesion with the adhesive mortar. This method, however, forces the failure to start and progress along the inner interface. This may influence the obtained result in cases where the failure would otherwise initially involve the outer interface as well.