## 3 Results
### Anti-Aging Performance  
#### 3.2.1 Anti-Aging Performance of RAMB Based on High-Temperature Rheological Performance  
The dynamic shear rheological test was performed on the short-term and long-term aging of asphalt and the \(\delta\) and G* values were obtained to calculate the aging index. The rutting indexes for the six asphalts were measured at different temperatures and three aging states (no aging, short-term aging and long-term aging), as shown in Figure 10. The G* value of three of the aging asphalts decreased and the \(\delta\) value increased as the temperature increased. The high temperature increases the mobility of the asphalt and reduces the anti-deforming capability. The G* value of all asphalts increased and the \(\delta\) value gradually decreased with aging at constant temperature. The physical hardening effect caused by aging favors the anti-deforming capability of asphalt. The rutting indexes of matrix asphalt, rock asphalt-modified bio-asphalt and RAMB met the requirements. RAMB had the highest G* value and the lowest \(\delta\) value. The rutting index of the original asphalt was 2.60 times that of the untreated bio-asphalt and 1.12 times that of the matrix asphalt at 64 \({}^{\circ}\)C. The rutting index of the short-term aging asphalt at 64 \({}^{\circ}\)C was 2.36 times that of the untreated bio-asphalt and 1.11 times that of the matrix asphalt.  
The aging resistance of asphalt was evaluated by calculating CMAI and PAAI using Equations (4) and (5). With smaller CMAI, larger PAAI indicates better aging resistance.  
\[\text{CMAI}=\frac{\text{Complex modulus of short or long term aging asphalt}}{\text{Complex modulus of original asphalt}} \tag{4}\]  
\[\text{PAAI}=\frac{\text{Phase angle of short or long term aging asphalt}}{\text{Phase angle of original asphalt}} \tag{5}\]  
The changes in CMAI and PAAI after short- and long-term aging of the six asphalts are shown in Figures 11 and 12. As seen from Figures 11 and 12, untreated bio-asphalt had the largest CMAI and the smallest PAAI in the range of 46 \({}^{\circ}\)C to 64 \({}^{\circ}\)C. This indicates that untreated bio-asphalt has poor aging resistance and the high-temperature rheological properties are greatly affected by aging because there are many light components in bio-asphalt. The volatilization of light components leads to the change in high-temperature performance of asphalt. The CMAI and PAAI of treated bio-asphalt were improved, compared to untreated bio-asphalt. The pretreatment of distilled water reduced the introduction of light components in matrix asphalt by removing the light components in bio-oil. Thus, the volatilization of light components in bio-asphalt was reduced during the aging. The addition of rock asphalt and montmorillonite reduced the CMAI and increased the PAAI of bio-asphalt. The performance of rock asphalt demonstrated little change under the influence of aging, meaning it can bear rutting deformation under high temperature by serving as the hard particles in bio-asphalt. Montmorillonite within the layered structure reduces  
Figure 9: S and m of six asphalts at \(-18\)\({}^{\circ}\)C.  
the volatilization of light components. Stability of asphalt components is maintained. This prevents oxygen incorporation and reduces the oxidation of asphalt components. The changes in bio-asphalt in terms of chemical composition are reduced. Therefore, the high-temperature rheological properties of treated bio-asphalt, rock asphalt-modified bio-asphalt and montmorillonite-modified bio-asphalt change little under the influence of aging. The CMAI of RAMB is less than that of other asphalts. The PAAI is greater than other asphalts. Its anti-aging properties are better. Bio-asphalt has good anti-aging performance with pretreatment, rock asphalt and montmorillonite.