| As the continuously growing of traffic volume and the number of heavy vehicles, the pressure of pavement is becoming heavier and heavier. It is of great significance to design a kind of sustainable asphalt pavement for considering the huge liquidity and the limitation of asphalt pavement service life for road transportation. Under the help of rest periods and hot summers, it is very useful to design a durable asphalt pavement with self repairing capacity because asphalt materials themselves have self-healing ability to some extend and can prolong the pavement service life. In order to achieve this goal, it is important to have an intensive research on the self-healing capacity of bituminous materials and take all kinds of measures to improve it.The study chose standard, unmodified bituminous mastics SK-70, SBS polymer modified bituminous mastics SK-70, and aging bituminous mastics SK-70 as the objects of study, and their self-healing capacities were evaluated and analyzed.Firstly, in this paper, the stress scanning, frequency scanning and temperature scanning tests were taken on the three mastics. The basic dynamic rheological change of them were analyzed after polymer modification and aging. Polymer SBS modification and aging make the |G*| become bigger and phase angle become less. Through the experimental data and related diagram, results show that the complex shear modulus value of them decline with the rise of temperature, meanwhile, the phase angle increases gradually. The complex shear modulus increase with the rise of loading frequency, and log Kow of |G*| has a good line relationship with that of loading frequency.Secondly, by testing the fatigue properties of them under selected temperature and stress level, combining the related domestic and foreign materials, a reasonable fatigue point was determined and a solid foundation was built for late fatigue-healing-fatigue tests. It was defined as the transition point of various macro-asphalt mortar dramatic changes in mechanical properties in the complex shear modulus (phase angle)-load cycles curves.Thirdly, through choosing attenuation and restore degree of the composite shear modulus for asphalt mastics as evaluation index, the fatigue-healing-fatigue tests were performed on them basing on the fatigue test. The self-healing capacities of them were studied at the same time. The results show that in the repeated loading forces, the anti-fatigue performance of bituminous mastics decreases since the healing ability become weak and the healing index HI becomes less. In the stress control mode of this research, the greater the loading force is, the higher the settled temperature is, the weaker the anti-fatigue and healing ability become. Overall, the self-healing ability of SBS modified bituminous mastics is better than that of unmodified bituminous mastics, and the healing ability of aging bituminous mastics is much weaker than that of unmodified bituminous mastics.Finally, the internal mechanism of self-healing capacity for asphalt mastics were analyzed from the angle of energy, and the dissipation theory was used in the bituminous mastics which was used for asphalt and HMA mixture previously so that a new breakthrough point for the development of follow-up study can be provided. |
