## 4 Experimental Results
### Ultimate Shear Strength  
The shear strengths corresponding to nominal flexural strength, the test results for SFRC beams, and the predicted shear strengths based on previous shear strength prediction models are summarized in Table 6. The shear strength a specimen was defined as half of the maximum force (V\({}_{\text{c,test}}=0.5\)P\({}_{\text{u,max}}\)). The symbol P\({}_{\text{u,max}}\) denotes the maximum of vertical load applied by the vertical actuator, while the symbol V\({}_{\text{n,f}}\)* stands for the shear strength corresponding to flexural strength. The effect of shear span-to-effective depth and longitudinal tensile reinforcement ratios can be observed from beam B1. For beam B2, only the effect of shear span-to-effective depth ratio was observed. Moreover, the mean and COV values for measured-to-predicted strengths are shown in Table 6.  
From beams B1 with a longitudinal reinforcement ratio of 0.75%, the shear strength of beams B1-2-0.75, B1-3-0.75, and beams B1-4-0.75 were 72.6 kN, 46.50 kN, and 35.70 kN, respectively. For series B1 with a longitudinal reinforcement ratio of 0.75%, the decrease of the ultimate shear stress due to the change of the shear span-to-effective depth ratio from 2 to 3, and 3 to 4 were about 36% and 23%, respectively. In series B1, with a longitudinal reinforcement ratio of 1.50%, the ultimate shear strength decrease was about 24% when the shear span-to-effective depth ratio increased from 2 to 3, and the shear span-to-effective depth ratio increasing from 3 to 4 led the shear strength to decrease by about 21%. In addition, improving the longitudinal tensile reinforcement ratio increased ultimate shear strength by about 46%, 73%, and 71% for beams with span-to-effective depth ratios of 2, 3, and 4, respectively. From series B2, the improvement of the shear span-to-effective depth ratio from 2.5 to 3 decreased ultimate shear strength by about 12%. In general, the test results present the effect of the shear span-to-effective depth ratio and the longitudinal tensile reinforcement ratio, as shown in Figures 1 and 2. According to Figure 1, increasing the shear span-to-effective depth ratio decreases the normalized ultimate shear strength by 14 to 24%. Therefore, the trend showing the decrease of ultimate shear strength with the increase of shear-span-to-effective depth ratio shown in Figure 1 agrees with the experimental results. Figure 2 shows the effect of the longitudinal tensile reinforcement ratio on the SFRC beam shear strength. It shows that improving the longitudinal tensile reinforcement ratio may increase the ultimate shear strength by approximately 60% or more. This agrees with the improvement of the shear strength from improving the longitudinal tensile reinforcement ratio that has been shown in this study. Furthermore, it can be known that the presence of the high longitudinal reinforcement ratio tends to decrease the rate of decrease of shear strength due to the increase of shear span-to-effective depth ratio. No effect of yield strength of longitudinal reinforcement was observed in the experimental program in this study. However, it can be predicted that varying the yield strength of longitudinal bar has no effect on shear strength of a normal reinforced concrete or SFRC beam that is designed to fail in shear. Comparison between Measured Shear Strength and Shear Strength Corresponding to Nominal Flexural Strength  
The shear corresponding to the flexural capacity of each beam is presented. The nominal flexural strength was calculated based on ACI ITG-4.3R-07 [40], and the tension stress of beam due to the presence of steel fibers was considered as well.