## 3 Test Results
### Test for Diagonal Tension Strength  
The stress-strain curves from the tests for the diagonal tension strength are plotted in Figure 7. The diagonal tension strength and shear modulus based on the stress-strain curves are summarized in Table 5. All the stresses in the strengthened specimen were calculated based on the cross-sectional area of the bare masonry prism, similar to the compressive strength tests. The average diagonal tension strength and shear modulus for the bare prisms were 0.29 and 1410 MPa, respectively. Strengthening with the ASFRM overlay on one side improved the diagonal tension strength of D-SF-20S and D-SF-30S to 2.34 and 2.47 MPa, respectively; however, the thickness of the overlay did not have a significant effect, as observed in the two specimens. Strengthening using the same material on both sides of the specimen resulted in a diagonal tension strength that was two times higher than that achieved by strengthening on one side; moreover, the thickness of the overlay resulted in a significant improvement in the diagonal tension strength, as observed for D-SF-20B and D-SF-30B. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{3}{c}{**Average**} & \multicolumn{3}{c}{**Rate of Increase (\%)**} \\ \cline{2-6}
**Specimens** & **Peak Load (kN)** & **Diagonal Tension Strength (MPa)** & **\(G_{m}\)** & **Diagonal Tension Strength** & \(G_{m}\) \\ \hline D-P & 11.9 & 0.29 & 1410 & - & - \\ D-NM-30S & 87.2 & 2.11 & 2210 & 628 & 56.7 \\ D-SF-20S & 96.7 & 2.34 & 3690 & 707 & 162 \\ D-SF-30S & 102 & 2.47 & 1920 & 752 & 36.2 \\ D-SFA-30S & 102 & 2.46 & 2840 & 748 & 101 \\ D-SFM-30S & 111 & 2.7 & 2340 & 831 & 66 \\ D-FEM-30S & 80.2 & 1.94 & 1870 & 569 & 32.6 \\ D-NM-30B & 141 & 3.41 & 10,000 & 1080 & 609 \\ D-SF-20B & 212 & 5.13 & 6940 & 1670 & 392 \\ D-SF-30B & 330 & 8.0 & 14,100 & 2660 & 900 \\ D-SFA-30B & 260 & 6.3 & 10,800 & 2070 & 666 \\ D-SFM-30B & 265 & 6.41 & 8260 & 2110 & 486 \\ D-PEM-30B & 257 & 6.23 & 6230 & 2050 & 342 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Diagonal tension strength test results. Figure 6: Damage state after termination of compression tests: (**a**) C-P; (**b**) C-SF-30S; (**c**) C-SF-30B. Strengthening using the ASFRM, as applied to D-SF-30S and D-SF-30B, resulted in a higher strength compared with strengthening using only a glass fiber mesh-reinforced mortar overlay, as applied to D-NM-30S and D-NM-30B, respectively. The difference in strength increased, particularly when strengthening was performed on both sides. By adding a glass fiber mesh to the ASFRM overlay, the diagonal tension strength increased by 0.23 MPa compared with strengthening on one side in D-SF-30S and D-SFM30S; however, it decreased by 1.59 MPa compared with strengthening on both sides in D-SF-30B and D-SFM30B. Therefore, the glass fiber mesh did not exert a consistent positive effect on the diagonal tension strength. The overall tendency of the improvement in the shear modulus was similar to that in the diagonal tension strength. Specimens D-SFA-30S and D-SFA-30B, whose shear connectors were installed between the ASFRM overlay and masonry, did not yield significant improvements in the diagonal tension strength compared with specimens D-SF-30S and D-SF-30B, which had no shear connectors. Specimens strengthened with the ASFRM achieved higher diagonal tension strengths compared with those strengthened with the PEFRM, particularly for strengthening on one side. The damage states of the specimens after failure in the diagonal tension strength tests are shown in Figure 8. Prisms without strengthening failed and exhibited cracks along the joints, as shown in Figure 8a. However, the mortar overlay reinforced with only a glass fiber mesh, as in D-NM-30S and D-NM-30B, was damaged, unlike the other strengthened specimens, as shown in Figure 8b. In contrast, cracks were not observed on the ASFRM overlay for D-SF-30S, as shown in Figure 8c, where the masonry layer exhibited a few cracks on the masonry unit and separation between the bed joint and masonry units, as shown in Figure 8d.