## 3 Evaluation of the Fabricated Looney Bin
### Evaluation of the Fabricated Looney Bin  
Initial trials for the Looney Bin were conducted on a non-proprietary UHPC without steel fibers. The collected data are shown in Table 2. Each result from the Looney Bin was a single data point representing the principal stresses at the failure of the cube. The side stresses at failure were determined by averaging the stress readings between the time of reaching the prescribed stress state and the time at failure. The \(\sigma_{1}\) stress was determined by finding the maximum stress. The three principal stresses were then arranged in the appropriate order by magnitude to describe a single test. Three replicate tests were conducted for each stress state, and an outlier analysis was used to remove outliers. Each stress state described in Table 2 is the average of at least two tests of the stress condition listed. If the replicate tests were too dissimilar in results, the data were discarded and the stress state was retested. The tables list the principal stresses at failure, the compressive strength of the concrete at the time of testing determined from a 75 mm \(\times\) 150 mm cylinder (fc), and the deviatoric polar angle where that data point falls on the failure surface (\(\theta\)). [PERSON] and [PERSON] developed a novel series of equations that were modified to fit concrete failure surface data in a variety of shapes [13]. After developing these equations, \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multicolumn{2}{c}{**Side Stresses**} & \multicolumn{2}{c}{**No. of Tests Averaged**} & \multicolumn{5}{c}{**Mpa**} \\ \cline{3-8} \multicolumn{2}{c}{} & \multicolumn{1}{c}{\(\sigma_{1}\)} & \(\sigma_{2}\) & \(\sigma_{3}\) & \(\mathbf{f_{c}}\) & \(\theta^{\circ}\) \\ \hline \multirow{8}{*}{TTTT} & 0–0 & 3 & 8.50 & 0.00 & 0.00 & 111.70 & 0.0 \\  & 1.38–1.38 & 2 & 6.86 & 1.50 & 1.47 & 121.18 & 0.3 \\  & 2.07–2.07 & 3 & 6.26 & 2.15 & 2.11 & 111.10 & 0.5 \\  & 2.76–2.76 & 2 & 5.28 & 2.81 & 2.71 & 115.74 & 1.9 \\  & 3.45–1.72 & 3 & 5.93 & 3.33 & 1.84 & 112.52 & 21.0 \\  & 3.45–3.45 & 2 & 8.63 & 3.42 & 3.40 & 107.71 & 0.1 \\  & 3.45–3.45 & 2 & 7.07 & 3.42 & 3.36 & 107.71 & 0.9 \\  & 3.45–3.45 & 2 & 7.37 & 3.52 & 3.43 & 126.35 & 1.2 \\  & 4.41–2.07 & 2 & 5.73 & 4.07 & 2.11 & 99.11 & 32.7 \\  & 6.41–4.41 & 3 & 6.74 & 4.10 & 4.09 & 126.35 & 0.1 \\ \hline \multirow{2}{*}{TT} & Proportional & 2 & 4.94 & 4.94 & 0.00 & 110.59 & 59.7 \\  & 2.41 & 2 & 4.62 & 2.53 & 0.00 & 110.59 & 33.2 \\ \hline \multirow{8}{*}{TT} & 1.38–1.38 & 2 & 1.35 & 1.33 & \(-\)16.26 & 120.13 & 59.9 \\  & 1.38–1.38 & 3 & 1.37 & 1.36 & \(-\)22.85 & 113.79 & 60.0 \\  & 2.07–2.07 & 2 & 2.04 & 2.00 & \(-\)28.36 & 111.84 & 59.9 \\ \cline{1-1}  & 2.07–2.07 & 2 & 2.11 & 2.03 & \(-\)20.95 & 113.79 & 59.8 \\ \cline{1-1}  & 2.76–1.38 & 2 & 2.70 & 1.37 & \(-\)19.44 & 111.84 & 56.9 \\ \cline{1-1}  & 2.76–2.76 & 2 & 2.78 & 2.67 & \(-\)14.68 & 120.13 & 59.7 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Looney Bin Data. Figure 14: TTC test procedure flowchart. the authors used the UHPC failure data they collected to define parameters for two failure surface shapes. The data used to define the parameters was from fiber-reinforced UHPC and for the following stress conditions: triaxial compression, tension-compression-compression, and biaxial compression. Due to the absence of data for stress conditions with more than one tensile direction, the authors presented two versions of their failure surface with different shapes on the tension end of the failure surface. One shape was parabolic until the point that represents the theoretical triaxial tension strength, labeled iteration No. 1. The other shape creates reverse curvature in the tension region to the point of theoretical triaxial tension strength, labeled iteration No. 7 [13]. The Looney Bin data are plotted against both failure models presented by [PERSON] and Curb  
Overall, the Looney Bin data plots in the expected regions of the failure models, providing evidence that the collected data are reasonable.