## 2 Compression Tests
### Triaxial Test Results  
The paper further studied the mechanical properties and failure characteristics of BFRGC under triaxial compression tests with the confining pressures chosen as 5 MPa and 8 MPa. The stress-strain curves under two confining pressures are shown in Figures 2 and 3, respectively. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Group**} & \multirow{2}{*}{\begin{tabular}{c} **Rubber** \\ **Particles** \\ **(\%)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Basalt** \\ **Fibers** \\ **(\%)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Basalt** \\ **Fibers** \\ **(kg-m3)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Rubber** \\ **Granular** \\ **(kg-m3)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Cement** \\ **(kg-m3)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **River** \\ **Sand** \\ **(kg-m3)** \\ \end{tabular} } & \multirow{2}{*}{\
\begin{tabular}{c} **Water** \\ **(kg-m3)** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **Binder** \\ **(kg-m3)** \\ \end{tabular} } \\ \hline \multirow{3}{*}{B} & B1 & & 0 & 0 & 57.76 & 380 & 570 & 133 & 5.7 & 8.66 \\  & B2 & 0.4\% & 4.64 & 57.76 & 380 & 570 & 133 & 5.7 & 8.66 \\  & B3 & 0.8\% & 9.32 & 57.76 & 380 & 570 & 133 & 5.7 & 8.66 \\  & B4 & & 1.2\% & 14.03 & 57.76 & 380 & 570 & 133 & 5.7 & 8.66 \\ \hline \multirow{3}{*}{C} & C1 & & 0 & 0 & 123.02 & 380 & 570 & 133 & 5.7 & 18.45 \\  & C2 & 0.4\% & 4.94 & 123.02 & 380 & 570 & 133 & 5.7 & 18.45 \\  & C3 & 0.8\% & 9.92 & 123.02 & 380 & 570 & 133 & 5.7 & 18.45 \\  & C4 & & 1.2\% & 14.94 & 123.02 & 380 & 570 & 133 & 5.7 & 18.45 \\ \hline \multirow{3}{*}{D} & D1 & & 0 & 0 & 282.78 & 380 & 570 & 133 & 5.7 & 42.42 \\  & D2 & 0.4\% & 5.68 & 282.78 & 380 & 570 & 133 & 5.7 & 42.42 \\  & D3 & 0.8\% & 11.40 & 282.78 & 380 & 570 & 133 & 5.7 & 42.42 \\  & D4 & & 1.2\% & 17.17 & 282.78 & 380 & 570 & 133 & 5.7 & 42.42 \\ \hline \multirow{3}{*}{E} & E1 & & 0 & 0 & 498.64 & 380 & 570 & 133 & 5.7 & 74.80 \\  & E2 & 0.4\% & 0.4\% & 6.68 & 498.64 & 380 & 570 & 133 & 5.7 & 74.80 \\ \cline{1-1}  & E3 & & 0.8\% & 13.40 & 498.64 & 380 & 570 & 133 & 5.7 & 74.80 \\ \cline{1-1}  & E4 & & 1.2\% & 20.19 & 498.64 & 380 & 570 & 133 & 5.7 & 74.80 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._  
Figure 2: _Cont._  
Figure 3: _Cont._  
Figure 2: Test results under confining pressure of 5 Mpa. (**a**) Group A; (**b**) group B; (**c**) group C; (**d**) group D; (**e**) group E.  
As shown in Figures 2 and 3, the yield strength increased gradually with increasing confining pressure, as would be expected. For A2, B2, C2, and D2, the yield states appeared when the strains were about 2-2.5%, while there were no peak strengths in group E. A comparison of the stress-strain curves in four groups A, B, C, and D indicated that as rubber particle content increased (from group A to group D), the peak strengths exhibited a noticeable decrease, and the downtrend of stresses after the peak strength became increasingly gentle. In addition, the maximum yield strengths were reached when the mass fraction of basalt fiber was 0.4%, which was consistent with the results of the uniaxial compression test obtained by [PERSON] et al. [27]. The failure feature of the specimens under 5 MPa and 8 MPa showed some similarities. Only the failure characteristics of the samples under the confining pressure of 5 MPa were analyzed in this paper, as shown in Figure 4. The failures of the specimen under 8 MPa are given in Figure A1. Figure 4: \(Cont.\)  
Figure 3: Test results under confining pressure of 8 MPa. (**a**) Group A; (**b**) group B; (**c**) group C; (**d**) group D; (**e**) group E.  
It can be seen in Figure 4a that the plain concrete (A1) exhibited more serious damage than the basalt fiber concrete (A2, A3, and A4) under the same loading conditions, and its failure mode was the typical split failure, similar to those under uniaxial loading condition.