## 2 Materials and Methods  
### Test Program and Test Specimens  
The experimental campaign consisted of reference tests at ambient temperature and tests at high temperature, themselves subdivided into two groups according to the heating scenario: the slow-rate heating or the ISO 834-1 fire conditions. The experimental matrix is summarized in Table 1, where the symbol T refers to the high-temperature conditions. Two medium embedment depths were considered, 75 mm and 125 mm, which were chosen with regard to the probability of observing concrete cone failure, their practical significance and the technical constraints during the tests. In fact, shallower bonded anchors are more likely to fail by pull-out, and they are also of minor importance due to their limited capacity. On the other hand, deeper anchors are less sensitive to concrete damage after any reasonable exposure time. With the slow-rate heating, the four anchors were tested under similar thermal conditions, while with the ISO 834-1 fire, different levels of heating (30 min, 60 min and 75 min of exposure) were targeted for a similar embedment depth of 125 mm. Moreover, additional specimens were cast to determine the mechanical properties of concrete at ambient temperature at the time of testing. These consisted of cubes with sides of 150 mm to determine the compressive strength of the concrete according to NF EN 12390-3 [26], cylinders of 160 mm in diameter and 320 mm in height to determine the splitting tensile strength according to NF EN 12390-6 [27] and the modulus of elasticity according to NF EN 12390-13 [28]. Moreover, 600 mm long, 150 mm wide and 150 mm thick prisms were dedicated to three-point bending tests to determine the fracture energy of concrete according to RILEM TC 162-TDF 2002 [29]. The tested anchors consisted of carbon steel threaded rods installed in the hardened concrete slabs 36 days after their pouring. The bonding material consisted of an inorganic adhesive mortar, for which the installation procedure and curing time were specified by the manufacturer. The bond resistance of the adhesive mortar at ambient temperature was also determined experimentally according to the relevant approval test procedure [30], in the same concrete batch and with the same embedment depths, on the basis of three tests per embedment depth. The characteristics and mechanical properties at ambient temperature of the different materials constituting the anchoring system are listed in Table 2.  
For the high-temperature tests, two thermocouple scales were installed inside each test specimen (Figure 1). The first was carried by a thin steel rod 3 mm in diameter, positioned perpendicularly to the exposed surface, to measure the temperatures of concrete at different \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Embedment Depth** & **75 mm** & **125 mm** & **Dimensions of Concrete Specimens** \\ \hline \multirow{6}{*}{Ambient temperature} & 75-1 & 125-2 & \multirow{6}{*}{All anchors are installed in a common slab L 2.5 m \(\times\) W 1.4 m \(\times\) T 0.4 m} \\  & 75-2 & 125-3 & \\  & 75-3 & 125-4 & \\  & 75-4 & 125-5 & \\ \multirow{2}{*}{Slow-rate heating} & 75-1 & 1T25-1 & Each anchor is installed in an individual slab L 1.5 m \(\times\) W 0.5 m \(\times\) T 0.4 m \\  & 75-2 & 1T25-2 & \\ \multirow{2}{*}{Fire ISO 834-1} & \multirow{2}{*}{-} & 1T25-ISO-30 & \multirow{2}{*}{Each anchor is installed in an individual slab L 1.5 m \(\times\) W 0.65 m \(\times\) T 0.4 m} \\  & & 1T25-ISO-75 & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Matrix of the test program. depths along the thickness of the slab. The second was carried by a non-loaded witness anchor, which had exactly the same characteristics as the loaded anchor. The only difference is that for the witness anchor, the hole drilled in the concrete crosses the entire thickness of the slab to bring out the thermocouples through the unexposed face. It measured the temperatures at the concrete-steel interface, i.e., the temperatures of the adhesive mortar along the embedment depth.