# Experimental Study on Flexural Capacity of Corroded RC Slabs Reinforced with Basalt Fiber Textile
## 3 Experimental Results and Discussion
### Flexural Capacity Analysis  
Table 5 summarizes the loads obtained in the experiments and contains: yield load (\(F_{y}\)) and ultimate load (\(F_{\text{u}}\)). The yield load was defined as the load corresponding to the tensile reinforcement yield. The ultimate load was defined as the peak load observed on the load-deflection curve. The flexural capacities (\(M_{\text{u}}\)) of slabs were obtained by utilizing the ultimate loads. The yields and ultimate loads of all strengthened slabs were generally higher than that of the control slabs. Under the moderate corrosion condition, the yield load of the strengthened slabs increased by 21.70%-50.0% and the flexural capacities increased by 27.81%-61.80% compared to that of the corresponding control slabs. Under the severe corrosion condition, these yield loads increased by 1.63%-19.11% and flexural capacities increased by 11.52%-33.27%. Figure 10 illustrates the comparison of normalized flexural capacity of strengthened slabs in different corrosion states. It can be seen that the flexural capacity of the BTRM-strengthened slabs was higher than that of the BFRP-strengthened specimens under the moderate corrosion condition. The highest flexural capacity, namely 21.18 kN\(\cdot\)m, was obtained from specimen M-M-5, which was strengthened by BTRM composites. Specimen M-M-5 was recorded as having a 12.48% higher flexural capacity increment when compared with that of specimen M-P-5. This abnormal phenomenon is likely due to the randomness of the sample. The strengthening technology and quality of M-M-5 was shown to be superior to the other specimens, while its curing time was longest because it was the last one to be tested. When the slabs were severely corroded, the capacity of the BTRM-strengthened specimens were slightly lower than that of the BFRP-strengthened specimens. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{
\begin{tabular}{c} **Specimen** \\ **ID** \\ \end{tabular} } & **Corrosion** & **Yield** & **Percentage** & **Ultimate** & **Flexural** & **Percentage** \\  & **Ratio** & **Load** & **Increase** & **Load** & **Capacity** & **Increase** \\  & **\(\boldsymbol{\eta}\) (\%)** & **\(\boldsymbol{F_{y}}\) (kN)** & **of \(\boldsymbol{F_{y}}\) (\%)** & **\(\boldsymbol{F_{u}}\) (kN)** & **\(\boldsymbol{M_{u}}\) (kN\(\cdot\)m)** & **of \(\boldsymbol{M_{u}}\) (\%)** \\ \hline M-C & 8.84 & 31.8 & – & 37.4 & 13.09 & – \\ M-P-3 & 7.68 & 38.7 & 21.70 & 47.8 & 16.73 & 27.81 \\ M-P-5 & 9.55 & 43.3 & 36.16 & 53.8 & 18.83 & 43.85 \\ M-M-3 & 8.37 & 44.5 & 39.94 & 48.2 & 16.87 & 28.88 \\ M-M-5 & 9.14 & 47.7 & 50.00 & 60.5 & 21.18 & 61.80 \\ S-C & 16.25 & 24.6 & – & 28.5 & 9.98 & – \\ S-P-3 & 15.81 & 25.0 & 1.63 & 33.2 & 11.62 & 16.43 \\ S-P-5 & 14.94 & 29.3 & 19.11 & 38.0 & 13.30 & 33.27 \\ S-M-3 & 16.43 & 25.7 & 4.47 & 31.8 & 11.13 & 11.52 \\ S-M-5 & 14.27 & 28.2 & 14.63 & 35.8 & 12.53 & 25.55 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Loads and flexural capacities of specimens. Figure 10: Comparison of normalized flexural capacity of strengthened slabs. The initial corrosion ratio could significantly affect the flexural capacities of specimens. According to the test result in reference [44], the flexural capacity of uncorroded RC slab with the same parameters was 20.60 kN\(\cdot\)m. When the initial corrosion ratio increased from 0% to 8.84% and finally to 16.25%, the flexural capacities of the control slabs dropped by 36.45% and 51.55%, respectively. From Figure 11, it can be concluded that the flexural capacities of strengthened specimens also decreased with the initial corrosion ratio increasing, and the rate of decrease was 0.8723. The influence of the number of strengthening layers on the slabs' flexural capacity is presented in Figure 12. When the number of strengthening layers was increased from 0 to 3 and finally to 5, the normalized flexural capacities increased by 29% and 62% in the moderate corrosion state, respectively; these capacities increased by 12% and 26%, respectively, in severe corrosion state.