## 4 Experimental Results
### Ultimate Shear Strength
By referring to research conducted by [PERSON] [41], the strain and stress distribution and internal force acting on the SFRC beam section are shown in Figure 7. The rectangular stress block is used for compression zone, while the nonlinear distribution starting from maximum tensile stress \(\left(\sigma_{pc}\right)\) near the neutral axis to minimum value at the extreme tension fiber is the actual tensile stress [41]. For simplification, the tensile stress distribution can be assumed as an inverse triangle with the maximum tensile stress on the neutral axis [41]. For any RC beams, the cracks appear at the extreme tension fiber first and continue developing from the extreme tension fiber to upper parts in tension zone. Therefore, it is acceptable to define the maximum tensile stress to be near the neutral axis and the smallest tensile stress to be at the extreme tension fiber. \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline  & & & & \multicolumn{6}{c}{**Predicted Shear Strengths (kN)**} \\ \cline{4-10}
**Specimen** & \(\mathbf{V_{n,f}}\) & \(\mathbf{V_{c,test}}\) (kN) & \multirow{2}{*}{\begin{tabular}{c} **[PERSON]** \\ **(1986)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **[PERSON]** \\ **and [PERSON]** \\ **(1987)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **[PERSON] et al. (1992)** \\ **[PERSON]** \\ **(5a)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **[PERSON]-** \\ **(6)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **[PERSON]** \\ **(2006)** \\ \end{tabular} } & \multirow{2}{*}{\
\begin{tabular}{c} **[PERSON]** \\ **(2009)** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **[PERSON]** \\ **(2014)** \\ \end{tabular} } \\ \hline B1-2-0.75 & 60.71 & 72.6 & 70.90 & 71.41 & 28.49 & 67.62 & 48.02 & 57.31 & 39.58 & 70.84 \\ B1-2-1.50 & 104.15 & 106.1 & 70.90 & 78.84 & 35.89 & 68.76 & 48.02 & 64.81 & 49.18 & 78.83 \\ B1-3-0.75 & 40.48 & 46.50 & 64.06 & 59.40 & 24.89 & 45.08 & 48.02 & 53.66 & 39.58 & 70.84 \\ B1-3-1.50 & 69.43 & 80.50 & 64.06 & 62.93 & 31.35 & 45.84 & 48.02 & 60.21 & 49.18 & 78.83 \\ B1-4-0.75 & 30.17 & 35.70 & 58.08 & 57.48 & 22.27 & 33.09 & 46.78 & 50.57 & 39.37 & 69.44 \\ B1-4-1.50 & 51.72 & 63.30 & 58.08 & 60.13 & 28.05 & 33.66 & 46.78 & 56.32 & 48.76 & 77.16 \\ B2-5-2.5-1 & 114.81 & 120.55 & 64.81 & 76.93 & 40.87 & 56.16 & 46.42 & 68.96 & 59.30 & 92.10 \\ B2-2-5.2-5 & 114.81 & 114.63 & 64.81 & 76.93 & 40.87 & 56.16 & 46.42 & 68.96 & 59.30 & 92.10 \\ B2-3-2-5 & 97.09 & 95.10 & 62.37 & 70.49 & 38.62 & 47.06 & 46.76 & 67.11 & 59.78 & 92.95 \\ B2-3-2-5 & 97.09 & 114.63 & 62.37 & 70.49 & 38.62 & 47.06 & 46.76 & 67.11 & 59.78 & 92.95 \\ \hline \multicolumn{2}{c}{Mean of \(\text{V}_{c,test}/\text{V}_{c,predicted}\)} & 1.32 & 1.21 & 2.50 & 1.70 & 1.80 & 1.35 & 1.65 & 1.02 \\ \hline \multicolumn{2}{c}{COV} & 0.34 & 0.28 & 0.19 & 0.29 & 0.36 & 0.27 & 0.25 & 0.28 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Comparison between measured and predicted strengths. As mentioned in ACI Committee 544 [42] and reported by [PERSON] [28], the compressive strain at the extreme layer of the compression zone ranged from 0.0035 to 0.004. Since the depth of the neutral axis is still unknown, the first key step in section analysis is to accomplish section equilibrium. Therefore, by assuming the beam to be only subjected to the bending (with axial force of zero), the sum of the compression force can be set to be equal to the sum of the tension force, as shown in Equation (13). Solving Equation (13) can be based on a trial and error procedure in order to determine the depth of the neutral axis. The nominal moment strength is expressed as the sum of the tension force multiplied by the moment arm, as shown in Equation (14). For all series B1, the shear strength corresponding to the flexural strength is less than the measured shear strength. By contrast, for all series B2, the measured strength tended to be similar to shear strength corresponding to flexural strength.