## 2 Materials and Methods
### Testing Procedure
& - & 5.31 (0.209) & 9.42 (0.371) & 10.66 (0.420) \\ Deflection increase under sustained load (\(\delta_{\mathrm{s}}\)) mm (in.) & - & 1.11 (0.043) & 3.55 (0.140) & 2.18 (0.085) \\ Creep coefficient—Ratio sustained to initial deflection (\(\delta_{\mathrm{s}}/\delta_{\mathrm{s}}\)) & - & 0.21 & 0.38 & 0.20 \\ Rotation under sustained load & - & 0.0027 & 0.0087 & 0.0054 \\ Sustained load deflection at 24 days (\(\delta_{\mathrm{  
control specimen BC1. Beam B2-SL's sustained load was near the yield moment, while the others were greater. None of these specimens failed under the sustained loads. During further loading, the beams experienced significant flexural cracking and deflection prior to the sudden final shear failure shown in Figure 11.  
BC5 served as a control specimen for beams series II and failed at a load of 18.35 kN (4216 lb). The failure mode was a sudden shear failure, as shown in Figure 12. The remaining beams in series II were tested under a first stage of sustained load with initial load levels of 84% (B6-SL), 91% (B7-SL), 95% (B9-SL), and 98% (B10-SL) of the strength of BC5. Under increasing levels of short period sustained loads, the shear-controlled beams that experienced sustained load exhibited significant flexural cracking and deflection before a sudden shear failure. \begin{table}
\begin{tabular}{c c c c c c} \hline
**Specimen** & **BC5** & **B6-SL** & **B7-SL** & **B9-SL** & **B10-SL** \\ \hline Sustained load kN (lb) & - & \begin{tabular}{c} 15.35 \\ (3750) \\ \end{tabular} & \begin{tabular}{c} 16.68 (3450) \\ \end{tabular} & \
\begin{tabular}{c} 17.48 (3750) \\ \end{tabular} &
\begin{tabular}{c} 18.02 (4050) \\ \end{tabular} \\ The reinforcement depth mm (in.) & 116 (4.573) & 112 (4.412) & 112 (4.423) & 111 (4.357) & 114 (4.473) \\ Sustained load intensity & - & 0.84 & 0.91 & 0.95 & 0.98 \\ (sustained load/peak load of BC1) & - & 0.71 & 0.89 & 0.91 & 1.00 \\ Actual sustained load intensity & - & 0.71 & 0.89 & 0.91 & 1.00 \\ (sustained load/measured peak load) & 18.35 & 21.75 & 18.70 (4205) & 19.26 (4330) & 18.02 (4050) \\ Peak load kN (lb) & (4216) & (4889) & 18.70 (4205) & 19.26 (4330) & 18.02 (4050) \\ Ratio of the peak load to the peak load of BCS & 1 & 1.18 & 1.02 & 1.05 & 0.98 \\ Deflection at the peak and failure mm (in.) & 5.64 & 18.45 & 17.60 (4.463) & 12.52 (0.493) & 6.13 (0.241) \\ Initial deflection under short-term loading deflection (\(\delta_{\mathrm{i}}\)) mm (in.) & - & 4.98 (0.196) & 6.45 (0.254) & 6.84 (0.269) & 5.87 (0.231) \\ Deflection under sustained load (\(\delta_{\mathrm{i}}\)) mm (in.) & - & 0.91 (0.036) & 1.60 (0.063) & 1.95 (0.077) & 0.26 (0.010) \\ Creep coefficient—Ratio sustained to initial deflection (\(\delta_{\mathrm{i}}\)/\(\delta_{\mathrm{i}}\)) & - & 0.19 & 0.25 & 0.29 & 0.05 \\ Rotation under sustained load & - & 0.0015 & 0.0026 & 0.0032 & 0.00043 \\ Sustained load deflection at 24 days (\(\delta_{\mathrm{i}}\)=24 days) mm (in.) & - & 0.90 (0.035) & 1.58 (0.062) & 1.92 (0.076) & - \\ Rotation at 24 days under sustained load & - & 0.0015 & 0.0026 & 0.0032 & - \\ \hline \end{tabular} Note: the load reported in this table is the point load (P).  
\end{table} 
Table 4: Beam series II test matrix and results. Figure 11: Beam series I failures. Specimen B10-SL, which was loaded to 98% of beam BC5's failure, load failed under sustained load (18 kN (3930 lb)) only 84.5 min after the sustained load level was obtained (total time of 104.5 min). All other specimens did not fail during the first stage of sustained load. The test results indicate that to fail under sustained load, the load level must be very close (within 2% in this case) to the short-time capacity. This is a higher capacity than the results by [PERSON] et al. (2015) in which the beams failed at 91% of the shear capacity. It is possible the compression reinforcement in this series of beams helped to increase the level at which failure would occur under sustained load. The demonstrated that a RC specimen has a significant ability to redistribute loads and thus survive under high sustained loads.