# Research on Mechanical Performance of Porous Asphalt Mixture with High-Viscosity Modified Asphalt
## 3 Research on Mechanical Performance of Porous Asphalt Mixture
### Research on Mechanical Performance of High-Viscosity Modified Asphalt Mixtures
#### 3.2.1 High Temperature Stability  
According to the Chinese specification JTG E20-2011 (T0719), in a high-temperature environment, if the ability of the asphalt mixture to resist shear stress is lower than the shear stress generated by vehicle loads, the pavement will produce rutting deformation [42]. This study used a high-temperature rutting test to verify the high-temperature stability of porous asphalt mixtures. The high-temperature rutting test involves subjecting mixture specimens to repeated wheel rolling under specified temperature conditions and evaluating the high-temperature stability of the asphalt mixtures based on the depth of rutting and test time. The test procedure is shown in Figure 12, and the test results are shown in Figure 13. The specific test requirements are as follows:  
1. Specim Formation: The specimen size is 300 mm \(\times\) 300 mm \(\times\) 50 mm, prepared using an indoor rutting tester. The test begins 48 h after the specimen is formed and left to stand.
2. Test Process: Before starting the test, the specimen should be placed in a 60 \({}^{\circ}\)C heat preservation box for 6 h. Then, a small rutting test machine should be used to perform the rutting and crushing test. The test temperature is 60 \({}^{\circ}\)C, the rubber wheel crushing pressure is 0.7 MPa, the crushing speed is 42 times per minute, and the crushing time is 1 h.
3. Data Collection: The rut depth and dynamic stability indices are obtained from the deformation depth versus time curve at the end of the wheel rolling.  
Figure 11: Grading curve.  
Excellent high-temperature rutting resistance is characterized by high dynamic stability and low rutting deformation depth. As shown in Figure 13, the dynamic stability of both 10-A and 10-B exceeded 5000 times/min, indicating that both mixes exhibit good high-temperature rutting resistance. Under the same mixture preparation process, 10-A demonstrated higher dynamic stability and lower rutting depth. This is because the modifier particles in 10-A melt and adhere to the aggregate surface at high temperatures, forming an adhesive film. This film enhances the adhesion between the aggregate and binder, thereby improving the deformation resistance of the mixture at high temperatures [43].  
These findings suggest that the 10-A modifier particles may enhance rutting resistance via a high-temperature fusion mechanism, aligning with the results reported by [PERSON] et al. (2017) [44; 45]. However, unlike previous studies concluding that merely increasing the SBS content improves the high-temperature performance of asphalt mixtures, our research indicates that increasing the ratio of the modifier antioxidant to the resin could be a critical factor in achieving superior performance. Future investigations should aim to further validate this hypothesis and elucidate the underlying mechanisms.  
Figure 12: Porous asphalt mixture high temperature rutting test. (a) Porous asphalt mixture. (b) Rut tester.  
Figure 13: Porous asphalt mixture high temperature rutting test result.