## 3 Test of Masonry Prisms Strengthened with SFRM Overlay
### Test Program
#### 3.1.1 Specimens  
The type of bricks, the number of strengthened faces, and the fiber volume ratios adopted for test variables are summarized in Table 6 with specimen names. Concrete and red clay bricks usually used for construction of bearing walls and external masonry veneers, respectively, were adopted to comprise masonry prisms and designated by C and R in the specimen names. In the specimen names, P designates the specimen without strengthening, S designates the specimen strengthened on a single surface, and B designates the specimen strengthened on both sides. The number that follows the characters in a specimen name represents the fiber volume fraction in percent in mortar overlay for strengthening. Due to lack of amorphous steel fibers, only two specimens were produced per RS1.0 and CS1.0 in Table 6. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Brick**} & \multirow{2}{*}{**SFRM Overlay**} & **Fiber Volume** & **Specimen** & \multicolumn{2}{c}{**Number of Specimens**} \\ \cline{3-5}  & & **Fraction (\%)** & **Name** & **Compression** & **Diagonal Tension** \\ \hline \multirow{4}{*}{Red clay brick} & No & - & RP & 3 & 3 \\ \cline{2-5}  & \multirow{2}{*}{1 side} & 1.0 & RS1.0 & 3 & 2 \\ \cline{3-5}  & & 1.3 & RS1.3 & 3 & 3 \\ \cline{2-5}  & \multirow{2}{*}{2 side} & 0 & RB0 & 3 & 3 \\ \cline{3-5}  & & 1.0 & RB1.0 & 3 & 3 \\ \cline{3-5}  & & 1.3 & RB1.3 & 3 & 3 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Design of test specimens. \begin{table}
\begin{tabular}{c c c} \hline \hline \multicolumn{2}{c}{**Experiment**} & \multicolumn{2}{c}{**SFRM Mixing Ratio**} \\ \hline \multirow{4}{*}{Workability} & \multirow{4}{*}{Flow} & S/C20-W/C40 \\  & & S/C15-S/C35 \\  & & S/C10-W/C32 \\ \cline{2-3}  & Adhesion & S/C20-W/C45 \\  & & S/C10-W/C32 \\ \hline \multirow{2}{*}{Strength} & Compressive & **-** \\ \cline{2-3}  & Tensile & S/C10-W/C32 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Determination of SFRM mixing ratio. The shapes and dimensions of test specimens for compression and diagonal tension tests, illustrated in Figure 7, comply with ASTM C 1314 [32] and ASTM E 519 [33], respectively. The dimension of both concrete bricks and red clay bricks is \(190\times 90\times 57\) mm. Concrete bricks are hollow but red clay bricks are solid, as is usual in Korea. The compressive strength of concrete bricks and red clay bricks tested in accordance with KS F 4004 [34] were 29.1 and 23.2 MPa, respectively. Joint mortar was made with a standard volume ratio of cement:sand = 1:3, as prescribed in KCS 41 34 02 [35]. [PERSON] et al. (2004) [36] proposed an empirical equation to predict the compressive strength of the joint mortar with respect to the sand-to-cement weight ratio. The test result for the compressive strength of the joint mortar used in this study that were cured in water was 33 MPa, which was almost similar to the 32.5 MPa predicted in accordance with [PERSON] et al. (2004) [36]. The prism specimen for compression strength test has a total of three layers laid-up in a stack bond pattern, while the diagonal tension prism has a total of six layers laid-up in a running bond pattern as illustrated in Figure 7. Both vertical and horizontal joints between bricks were filled with mortar without a visual gap. As shown in Figure 8, strengthened prisms were produced by plastering SFRM repetitively on bare masonry prisms 28 days after lay-up. A total thickness of 30 mm were plastered in three times with an interval of 24 h, according to the adhesion test result described previously. Water was sprayed on the bare masonry before plastering SFRM. All of the SFRM-overlaid prisms were cured in air dry conditions and room temperature.