## 3 Test Results and Discussions
### Effect of Chloride Environment
The CE_E coupons showed longitudinal cracks that appeared during the tensile test (Figure 9a), during which cracking is expected to be related to bond deterioration. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Cracking Tensile**} & \multicolumn{2}{c}{**Cracking Tensile**} & \multicolumn{2}{c}{**First Stiffness**} & \multicolumn{2}{c}{**Ultimate Tensile**} & \multicolumn{2}{c}{**Ultimate Tensile**} & \multicolumn{2}{c}{**Second Stiffness**} \\ \cline{2-13}
**Test Coupons** & \multicolumn{2}{c}{\(f_{\epsilon}\)} & \multicolumn{2}{c}{**Aver. \(f_{\epsilon}\)**} & \multicolumn{2}{c}{\(\epsilon_{c}\)} & \multicolumn{2}{c}{**Aver. \(\epsilon_{c}\)**} & \multicolumn{2}{c}{\(E_{1}\)**} & \multicolumn{2}{c}{**Aver. \(E_{1}\)**} & \multicolumn{2}{c}{**Aver. \(E_{1}\)**} & \multicolumn{2}{c}{**Aver. \(f_{\epsilon}\)**} & \multicolumn{2}{c}{**Aver. \(f_{\epsilon}\)**} & \multicolumn{2}{c}{**Aver. \(\epsilon_{c}\)**} & \multicolumn{2}{c}{**\(E_{2}\)**} & \multicolumn{2}{c}{**Aver. \(E_{2}\)**} \\  & **(MPa)** & **(MPa)** & **(\%)** & **(\%)** & **(\%)** & **(MPa)** & **(MPa)** & **(MPa)** & **(MPa)** & **(\%)** & **(\%)** & **(MPa)** \\ \hline CE1 & 0.76 & 0.80 & 0.050 & 1525.00 & 1707.31 & 2.25 & 2.29 & 0.661 & 0.634 & 189.84 & 199.30 \\ CE2 & 0.83 & 0.80 & 0.044 & 0.047 & 1889.61 & 1707.31 & 2.33 & 2.29 & 0.606 & 0.634 & 189.84 & 199.30 \\ CE\_E & 0.74 & - & 0.042 & - & 1780.00 & - & 2.35 & - & 0.550 & - & 190.91 & - \\ CE\_ESI & 0.64 & 0.71 & 0.040 & 1613.67 & 2.47 & 2.47 & 0.772 & 247.22 & 247.22 & 247.22 & 247.22 & 247.22 \\ CE\_ES2 & 0.78 & 0.044 & 0.042 & 1762.50 & 2.41 & 2.44 & 0.461 & 0.617 & 519.00 & 383.11 \\ \hline HTHE1 & 0.66 & 0.66 & 0.061 & 0.069 & 1093.13 & 961.74 & 2.83 & 2.70 & 1.017 & 132.39 & 170.30 \\ HTHE2 & 0.65 & 0.078 & 0.078 & 830.36 & 2.58 & 2.70 & 0.772 & 0.894 & 1208.21 & 170.30 \\ HTHE\_E1 & 0.69 & 0.078 & 0.078 & 898.29 & 2.8 & 0.978 & 0.978 & 2.45 & 128.13 & 142.44 \\ HTHE\_E2 & 0.75 & 0.72 & 0.067 & 0.073 & 1125.00 & 1007.15 & 2.58 & 2.43 & 1.267 & 156.74 & 142.44 \\ HTHE\_E & 0.68 & - & 0.067 & - & 1018.75 & - & 2.29 & - & 1.01 & - & 106.68 & - \\ \hline SL1 & 0.77 & 0.056 & 0.050 & 1387.50 & 2.82 & 2.82 & 3.00 & 1.044 & 0.956 & 148.53 & 169.05 \\ SL2 & 0.73 & 0.044 & 0.050 & 1631.25 & 3.18 & 3.18 & 0.867 & 189.56 & 169.05 & 169.05 \\ SL\_E1 & 0.93 & 0.08 & 0.058 & 1359.76 & 2.39 & 2.39 & 0.579 & 201.69 & 201.69 & 200.68 \\ SL\_E2 & 0.62 & 0.62 & 0.039 & 0.054 & 1585.71 & 1472.74 & 2.73 & 2.56 & 0.744 & 0.662 & 199.66 & 200.68 \\ SL\_ES & 0.69 & - & 0.044 & - & 1556.25 & - & 2.98 & - & 0.472 & - & 458.57 & - \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Tensile behavioral characteristics obtained from the experimental results. Additionally, the results of TRM coupons in this series were compared to the previous test results of TRM coupons [39], with slightly different amounts and details of carbon fiber without exposure to the chloride environment. The reference TRM coupons in the previous study were Com, Com_E, and Com_ES series; the coupons Com, Com_E, and Com_ES mean the comparative coupons without surface treatment, the comparative coupons with epoxy impregnation, and the comparative coupons with sand coating after epoxy impregnation, respectively. Figure 14 presents the previous test results of the TRM coupons under sound conditions. Figures 12a and 14a show that the CE and Com coupons without surface treatment revealed a significant difference in stiffness. In addition, those TRM coupons showed approximately 20% strength and 30% deformability differences. The initial stiffness and ultimate tensile strength of the CE series under chloride environment were decreased by 25-50% and 50%, respectively, compared to those of the Com series under sound conditions. This is because the chloride ion could penetrate inside the mortar and weaken the properties of the textile and the interfaces between textile and epoxy.