# Shear Performance for Prestressed Concrete Hollow Core Slabs
## 4 Experimental Results and Discussion
### Analysis of Key Influence Factors On the Web-Shear Capacity  
As mentioned in Section 2, due to the vulnerable structure resulting from prestress and hollow cores, shear strength of HCS is likely to be determined by web-shear strength rather than flexural-shear strength. For a more objective evaluation of the effects of web-shear strength, a comparative analysis was performed with experimental results from previous studies as key influence factors [6; 18; 19; 20; 21; 22; 23]. 164 sets of experimental data were retrieved from previous studies, and a summary is provided in Table 4.  
Figure 11 compares the experimental results with the results of previous studies; shear strength was nondimensionalized (\(\
u_{test}/\sqrt{f_{c}^{\prime}}\)) for more objective comparison of key influence factors. From Figure 11a,b, with increasing compressive strength and shear span-to-depth ratio, we can see a proportionate increase in both experimental results and previous study results. The variable shown in Figure 11c, which shows the effect of compressive stress with consideration of stress loss of prestress at the cross-sectional centroid, showed a more prominent increase compared to other variables, and had the greatest influence on web-shear strength. This is also indicated in previous studies of prestressed concrete beams under shear and torsional loading [24]. In Figure 11d, which shows member height as a variable, both experimental results and results from previous studies decreased in similar ways. However, compared to the web-shear strength (\(0.29\sqrt{f_{c}^{\prime}}\)) recommended in the design codes, the results were consistent with those of previous studies. As reported by [PERSON] and [PERSON] [5], HCS members were not significantly affected by size.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Researchers** & \(f_{c}\) **(MPa)** & **\(h\) (mm)** & **\(b_{w}\)** (mm)** & **\(d_{p}\)** (mm)** & **\(A_{g}\)** (mm\({}^{2}\))** & **\(A_{ps}\)** (mm\({}^{2}\))** & **\(f_{pc}\)** (MPa)** & **\(V_{test}\)** (\(\mathbf{k}\)N)** \\ \hline [PERSON] and [PERSON] [6] & 53.9 & 304.8 & 299.5 & 256.5 & - & 954.8 & 25.4-0.0 & 1.0–5.5 & 221.2 \\ (24 specimens) & –68.7 & –508.0 & –438.9 & –448.8 & - & –1587.1 & 2.5–4.0 & 1.0–5.5 & 221.2 \\ \hline [PERSON] [18] & 38.1 & 200.0 & 215.0 & 160.0 & 1190.0 & 372.0 & 2.7–5.7 & 1.8–7.0 & 80.4 \\ (50 specimens) & –63.7 & –500.0 & –335.0 & –453.0 & –3000.0 & –1953.0 & 2.7–5.7 & 1.8–7.0 & 528.0 \\ \hline Walraven and Merck [19] & 64.0 & 255.0 & 250.0 & 225.0 & 1710.0 & 470.0 & 1.7–6.7 & 2.5–5.9 & 181.6 \\ (19 specimens) & 64.0 & –300.0 & –294.0 & –265.0 & –1990.0 & –940.0 & - & & 2286.3 \\ \hline TNO [20] & 55.9 & 255.0 & 241.0 & 202.0 & 1720.0 & 853.7 & 2.9–3.2 & 3.6–8.8 & 224.0 \\ (39 specimens) & –113.9 & –400.0 & –449.0 & –350.0 & –2610.0 & –1684.4 & 2.9–3.2 & 3.6–8.8 & 224.0 \\ \hline [PERSON] and Mancini [21] & 55.0 & 163.0 & 335.0 & 133.0 & 1120.0 & 278.8 & 2.8–4.5 & 2.3–6.8 & 97.0 \\ (14 specimens) & –65.7 & –421.5 & –444.0 & –378.5 & –2380.0 & –1435.0 & 2.8–4.5 & 2.3–6.8 & 97.0 \\ \hline [PERSON] [22] & 62.9 & 206.0 & 229.0 & 158.0 & 1501.4 & 502.5 & 2.0– & 2.0– & 2.0–8.0 \\ (8 specimens) & –67.9 & –305.0 & –313.0 & –255.0 & –2069.9 & –888.3 & 3.0–3.8 & 3.6–5.0 & 163.0 \\ \hline [PERSON] et al. [23] & 60.5 & 200.0 & 242.0 & 168.0 & 1215.9 & 504.8 & 2.5–3.1 & 4.0–5.1 & 81.9 \\ (10 specimens) & 60.5 & –500.0 & –300.0 & –452.0 & –2554.1 & –899.6 & 2.5–3.1 & 4.0–5.1 & 81.9 \\ \hline \hline \end{tabular} \(A_{g}\)—cross sectional area; \(A_{ps}\)—cross sectional area of tendon; \(f_{pc}\)—prestness introduced in centroid of section.  
\end{table}
Table 4: Summary of previous studies.  
Figure 11: _Cont._