## 3 Results and Discussion
### Correlation Analysis  
In this section, the data of the calculated nominal bonding stress between the same kind of fiber (1# fiber or 2# fiber) and the asphalt mortar with different powder cement ratios were collected to do the correlation analysis with the test results of the rutting factor and the complex viscosity. It should be mentioned that the rheological indexes were tested under four kinds of temperatures (40 \({}^{\circ}\)C, 46 \({}^{\circ}\)C, 52 \({}^{\circ}\)C, 58 \({}^{\circ}\)C). In order to find at which temperature the nominal bonding stress has the best correlation with the rheological indexes, this section adopted the rheological tests results at 40 \({}^{\circ}\)C, 46 \({}^{\circ}\)C, 52 \({}^{\circ}\)C, and 58 \({}^{\circ}\)C to conduct the correlation analysis between the rheological indexes and the nominal bonding stress. The fiber asphalt pulling test was carried out at 40 \({}^{\circ}\)C. Therefore, this section also aims to verify the reliability of the test results of the nominal bonding stress. Because if \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Fiber** & **FB = 0.8** & **FB = 1.0** & **FB = 1.2** & **FB = 1.4** \\ \hline
1\# & 22.307 MPa & 26.851 MPa & 35.954 MPa & 51.247 MPa \\
2\# & 23.620 MPa & 27.124 MPa & 31.783 MPa & 57.580 MPa \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Results of nominal bonding stress. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Fiber** & **FB = 0.8** & **FB = 1.0** & **FB = 1.2** & **FB = 1.4** \\ \hline
1\# & 1.463 N & 1.761 N & 2.358 N & 3.361 N \\
2\# & 1.085 N & 1.246 N & 1.460 N & 2.645 N \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Average maximum pulling force. the test results of the fiber asphalt pulling test and the nominal bonding stress are accurate enough, the coefficient of determination (R\({}^{2}\)) of the correlation analysis results will be bigger than the other situations when the temperatures of the rheological test is at 40 \({}^{\circ}\)C (the same temperature as the test temperature of the fiber asphalt pulling test). It can be concluded from Figures 14 and 15 that, when the fibers are the same, the correlation analysis results show that the coefficient of determination (R\({}^{2}\)) increases when the temperature of the rutting factor and the complex viscosity decrease, and the R\({}^{2}\) value is the biggest when the test temperature of the two rheological indexes is 40 \({}^{\circ}\)C (the same temperature as the test temperature of the fiber asphalt pulling test), and the R\({}^{2}\) values are all bigger than 0.95 in this situation. This phenomenon shows that the nominal bonding stress calculated from the test results of the newly developed fiber asphalt pulling test has a good correlation with the rheological properties of the asphalt mortar, because higher R\({}^{2}\) value means better correlation between these two indexes. Moreover, the reliability of the nominal bonding stress derived from this new test is credible. Figure 12: Rutting factor. Figure 13: Complex viscosity. Figure 14: Correlation between bonding strength and rutting factor: **(a)** 40 \({}^{\circ}\)C-1\(\#\); **(b)** 46 \({}^{\circ}\)C-1\(\#\); **(c)** 52 \({}^{\circ}\)C-1\(\#\); **(d)** 58 \({}^{\circ}\)C-1\(\#\); **(e)** 40 \({}^{\circ}\)C-2\(\#\); **(f)** 46 \({}^{\circ}\)C-2\(\#\); **(g)** 52 \({}^{\circ}\)C-2\(\#\); **(h)** 58 \({}^{\circ}\)C-2\(\#\). Considering that the cost of the fiber asphalt pulling test or machine are far lower than the rheological test or instrument and that this newly developed test can both reveal the rheological property of the asphalt mortar to some extent and reveal the bonding between basalt fiber and the asphalt mortar in the basalt fiber reinforced asphalt composite materials, the nominal bonding stress between basalt fiber and asphalt mortar is reliable and accurate enough. In further studies, the nominal bonding stress (NBS) index might also be used to predict or give a prediction equation of the basalt fiber reinforced asphalt composite materials.