## 3 Results
### Load-Displacement Curves and Ultimate Capacities  
In Figure 12, the load-displacement curves recorded during the tests at ambient temperature and in the tests with slow-rate heating are presented, except for 75-3, for which the displacement could not be measured correctly. Figure 11: Disoloration of the aggregate particles near the exposed surface. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Test Conditions** & **Test ID** & \(\mathbf{h_{\text{ef}}}\) & \(\mathbf{r_{\text{max}}}\) & \(\mathbf{\beta}\) \\ \hline  & 75-1 & 75 mm & 2.8 h\({}_{\text{ef}}\) & \(17^{\circ}\leq\beta\leq 22^{\circ}\) \\
**Ambient** & 75-2 & 75 mm & 3.2 h\({}_{\text{ef}}\) & \(17^{\circ}\leq\beta\leq 28^{\circ}\) \\
**temperature** & 75-3 & 75 mm & 2.5 h\({}_{\text{ef}}\) & \(16^{\circ}\leq\beta\leq 25^{\circ}\) \\  & 75-4 & 75 mm & 1.8 h\({}_{\text{ef}}\) & \(28^{\circ}\leq\beta\leq 39^{\circ}\) \\ \hline
**Slow-rate** & T75-1 & 75 mm & 2.4 h\({}_{\text{ef}}\) & \(26^{\circ}\leq\beta\leq 48^{\circ}\) \\
**heating** & T75-2 & 75 mm & 2.1 h\({}_{\text{ef}}\) & \(22^{\circ}\leq\beta\leq 27^{\circ}\) \\ \hline
**ISO 834-1 fire** & T125-ISO-30 & 125 mm & 5.2 h\({}_{\text{ef}}\) & \(19^{\circ}\leq\beta\leq 34^{\circ}\) \\
**conditions** & T125-ISO-60 & 125 mm & 5.5 h\({}_{\text{ef}}\) & \(20^{\circ}\leq\beta\leq 44^{\circ}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Geometrical characteristics of the concrete cones. Figure 10: Failure angle and maximum radius of the concrete cone. For the 75 mm anchors, which all experienced concrete cone failure, the load-displacement curves show a first linear phase more or less overlapping for all the tests, whether at room or high temperature. Then, at high temperature, this phase is followed by a second non-linear phase, where the slope of the load-displacement curve decreases. The behaviors of the two anchors were different in this non-linear phase, resulting in different displacements despite quite similar peak loads. For the 125 mm anchors, which failed by combined failure, a first linear phase can also be seen in the load-displacement curves, where the curves are more or less superimposed for the tests at ambient temperature, except for 125-1. At high temperature, the curves have a less steep slope from the beginning of the tests, showing a more ductile behavior. The pre-peak branch does not appear to be clearly divided into linear and non-linear phases. Moreover, the post-peak phase shows a less abrupt decrease in capacity than at ambient temperature. The ultimate capacities F\({}_{\text{u,i}}\) recorded in each of the tests are presented in Table 4, together with the loss of capacity due to fire, determined with reference to the mean ultimate capacity measured at ambient temperature, which was 43.2 kN for 75 mm anchors (concrete cone failure) and 108.7 kN for 125 mm anchors (combined failure). It is shown in Table 4 that the loss of capacity was greater for the 125 mm anchors than for the 75 mm anchors after a similar duration of exposure to slow-rate heating. This is because the combined failure of 125 mm anchors at high temperature combines a loss of capacity associated with the concrete cone part and a loss of capacity associated with the lowered bond strength of the mortar. Regarding the four anchors that failed by the clear concrete cone (T75-1, T75-2, T125-ISO-30 and T125-ISO-60), the 125 mm anchors exposed to ISO 834-1 fire conditions lost a greater percentage of their capacities at room temperature, compared to the 75 mm anchors exposed to slow-rate heating despite a significantly shorter exposure time and despite the fact that the 75 mm anchors were entirely positioned in concrete at over 100 \({}^{\circ}\)C, while the 125 mm anchors were surrounded by concrete at under 100 \({}^{\circ}\)C over half of their depths. This supports the previous assertion that the temperature of the concrete near the surface of the slab is particularly important for the concrete cone capacity.