## 4 Performance Evaluation of Void Slab with Shear Reinforcement
### Shear Capacity Evaluation Based on Standard Formulae in Different Codes
#### 4.1.2 Ubc 2  
The expected shear strengths for all test specimens were calculated following the Uniform Building Code 2 (UBC 2) design code procedures, commonly used in the western United States. Tables 5-7 summarise the results, categorised by the type of shear reinforcement (unreinforced, 45-degree, and 90-degree) and the hollow core ratio:  
* Building upon the findings from the ACI code analysis (Section 4.1.1), unreinforced specimens continued to exhibit a range of expected shear strengths. This variation spanned from a minimum value of 1.97 for HC-35 (void ratio of 35%) to a maximum  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**No Reinforcement**} & \multicolumn{3}{c}{**45\({}^{\circ}\) Reinforcement**} & \multicolumn{3}{c}{**90\({}^{\circ}\) Reinforcement**} \\ \hline
**Name** & **HC-30** & **HC-35** & **H-C40** & **HC-30-45** & **HC-35-45** & **HC-40-45** & **H-C30-90** & **HC-35-90** & **HC-40-90** \\ \hline \(\mathrm{V_{test}}\) (kN) & 395.5 & 335.8 & 340.9 & 430.2 & 403.3 & 366.2 & 425.7 & 358.3 & 341.1 \\ \(\mathrm{V_{ACI}}\) & 185.9 & 172.4 & 159.2 & 263.0 & 249.8 & 236.7 & 262.6 & 249.5 & 236.3 \\ \(\mathrm{V_{test}}/\mathrm{V_{ACI}}\) & 2.13 & 1.95 & 2.14 & 1.64 & 1.61 & 1.55 & 1.62 & 1.44 & 1.44 \\ \hline AVG. & & 2.07 & & 1.6 & & & 1.5 & \\ Var. & & 0.011 & & 0.002 & & & 0.011 & \\ S.D. & & 0.107 & & 0.046 & & & 0.104 & \\ \hline \hline \end{tabular} Note: AVG. is average, Var. is Variance, and S.D. is Standard Deviation.  
\end{table}
Table 5: Ratios between experimental shear capacity and expected shear capacity with different reinforcements from ACI 318-14.  
value of 2.16 for both HC-40 and HC-30 (void ratios of 40 and 30%, respectively). The average expected shear strength for this group was 2.10. Additionally, the variance and standard deviation were 0.012 and 0.11, respectively (See Table 6).
* In contrast to the unreinforced specimens, those with a 45-degree shear reinforcement displayed a significantly narrower range of expected shear strengths. This range varied from a minimum of 1.56 to a maximum of 1.65. Notably, the average expected shear strength for this group was 1.60.
* Furthermore, the variance (0.002) and standard deviation (0.046) were both considerably lower compared to the unreinforced group. These reduced values suggest a more consistent performance in terms of expected shear strength for specimens with a 45-degree reinforcement. This observation aligns with the findings from the ACI code analysis (Section 4.1.1), where similar trends were observed for 45-degree reinforced specimens.
* Similar to the observations for unreinforced and 45-degree reinforced specimens, the expected shear strength of specimens with a 90-degree reinforcement also exhibited variations based on the hollow core ratio. The minimum value was 1.45 for both HC-35-90 and HC-40-90 (void ratios of 35 and 40%, respectively). This value increased to a maximum of 1.63 for HC-30-90 (void ratio of 30%).
* The average expected shear strength for the 90-degree group was 1.51, with a variance of 0.011 and a standard deviation of 0.104. These findings suggest that the hollow core ratio remains a factor influencing expected shear strength even with a 90-degree reinforcement.