## 3 The Experimental Campaign
### Investigated Parameters
#### 3.3.1 Anchor Location  
The overall behavior of an anchor installed in masonry, in terms of maximum capacity, stiffness, deformation at failure, mode of failure, etc., is expected to depend on the exact location of the anchor. Differences in behavior are expected between anchors installed in bricks and those installed in masonry joints. Whether the anchor is installed in a header or in a stretcher may also affect its behavior. It is also reasonable to anticipate that the typically lower quality of the mortar in vertical joints will lead to worse behavior than for anchors installed in a bed mortar joint, presumably of better quality and benefiting from the normal compressive stress on the wall. Nonetheless, for the reasons explained in Section 3.3.2 and after preliminary tests, the decision was made to test at the T-joint location, i.e., at the intersection of a vertical and a horizontal joint. It should also be noted that cracks expected to occur due to a seismic event, typically, pass through mortar joints, as in most cases the mechanical properties of the mortars are significantly lower than those of (solid) masonry units. Thus, cracks in horizontal mortar joints were formed in wallettes, where anchors were to be installed either to bricks or mortar joints.  
For the design of the experimental campaign, the following was considered: (a) In practice, one cannot expect and cannot impose the application of chemical anchors to the best possible location of masonry. Therefore, both brick and mortar joint locations were investigated within the program. (b) Although in practice, an anchor may be installed at any point of a brick (along its height or its length), the case of anchors installed in the middle of a brick is examined in this part of the experimental work. Other locations within a brick are examined in subsequent parts of the research. (c) For anchors installed in mortar joints, the most adverse location (after that of vertical joints was excluded) was selected for investigation, namely the intersection of a bed and a vertical mortar joint. Furthermore, (d) the case of cracks occurring due to a seismic event in the vicinity of anchors was given special attention, as described in more detail herein.  
The anchor locations accounted for within the work presented in this paper are shown in Figure 3.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Threaded Rod M12** & \\ \hline Nominal diameter of drill bit, d\({}_{0}\) (mm) & 14 \\ Drill hole depth = embedment depth, h\({}_{0}\) = h\({}_{\text{ef}}\) (mm) & 50...300 \\ Maximum diameter of clearance hole in the fixture, d\({}_{\text{r}}\) (mm) & 14 \\ Minimum wall thickness, h\({}_{\text{min}}\) (mm) & h\({}_{0}\) + 30 \\ Brush HIT-RB & 14 \\ Maximum torque moment, Tmax (Nm) & 10 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Installation parameters of threaded rods in solid bricks ETA19/0160 [19].  
Among the possible anchor locations, L\({}_{1}\) (anchor installed in the middle of a brick, in a masonry element free of cracks) is expected to exhibit the highest resistance. Thus, within the entire campaign, this location serves as a reference for the assessment of the behavior in other locations. An alternative to L\({}_{1}\) is location L\({}_{6}\), where the anchor is installed in the middle of an uncracked brick, but there is a horizontal crack through one of the bed joints adjacent to the brick.  
For anchors installed in mortar joints, the reference location is L\({}_{3T}\), i.e., the anchor is installed at the intersection of the horizontal and vertical joints, both of them being uncracked. Location L\({}_{3H}\), where the anchor is installed in the horizontal joint between two brick units, was also investigated (not shown in Figure 3). Nonetheless, as location L\({}_{3H}\) was proven to be more favorable than L\({}_{3T}\), the latter was exhaustively investigated within the project, as well as its equivalent under cracked conditions, L\({}_{4T}\).