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To solve the early rutting failure of asphalt pavement, the application of rock asphalt from Sichuan, China, based on anti-rutting performance, was studied. Preparations of North Sichuan rock asphalt (NS RA) and NS RA-modified asphalt mixture were elaborated in detail. Using Zhonghai AH-70 asphalt, Esso AH-70 asphalt, North American rock asphalt (NA RA) and NS RA, the performances of NS RA modified asphalt were researched based on index tests, Brookfield rotary viscosity test and bending beam rheometer test. A performance verification of NS RA-modified asphalt was carried out using rutting calculation, the rutting, indirect tensile fatigue, freeze–thaw split and small beam bending tests based on five kinds of selected gradations. The results indicated that in comparison with NA RA, the NS RA has a good modification effect as well. The NS RA can obviously improve the anti-rutting ability of the asphalt binder, and it can enhance its anti-aging performance as well. For the NS RA-modified asphalt mixture, it is feasible to determine the optimum NS RA content, based on its anti-rutting performance, and its optimum NS RA content is about 8%. The dynamic stability values of NS RA-modified asphalt mixtures are at least 3-fold higher than those of the base asphalt mixtures, and they are all far greater than the summer hot area requirement (no less than 2800 times/mm). NS RA-modified asphalt mixtures used in the middle course of asphalt pavement can obviously improve the anti-rutting performance of the pavement, and to enhance the anti-rutting ability of pavements, it should be used in the middle course of the pavement. The fatigue life values of NS RA-modified asphalt mixtures are at least 14.5-fold higher than those of the base asphalt mixtures. The freeze–thaw splitting strength ratio values of NS RA-modified asphalt mixtures are improved by at least 9.5% over the base asphalt mixtures, and their freeze–thaw splitting strength ratio values are all greater than the requirement (no less than 75%). In comparison with the base asphalt, the low temperature performances of NS RA-modified asphalt and its mixtures slightly decline, but they can meet the requirements for the zones with a minimum temperature of no less than –21.5 °C too. Therefore, except for the extremely low temperature area, it is an effective method for solving the rutting problem of pavement for using NS RA-modified asphalt. [ABSTRACT FROM AUTHOR]

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The self-healing properties of asphalt pavements reduce the need for frequent maintenance and repair of cracks and promote road sustainability. In this study, multiple healing tests were conducted under different healing conditions using the semicircular bending "crack-heal-crack" test. The beneficial effects of the healing temperatures and times were determined. However, below 60 °C, the healing index of asphalt mixture does not exceed 0.4. The peak healing indices of the 70# asphalt mixture in the fourth healing stage were 86% of the initial healing index. This correspond to the SBS# asphalt mixture parameters of 88%. Using the acoustic emission system, changes in the ring count and energy of the specimens before and after the healing were compared. The healing index of the cumulative ring count proposed in this study sufficiently correlates with that of the peak load. According to the three-dimensional time-difference positioning method, at the initial loading stage of the prehealing specimen, cracks first appeared at the top of the specimen in contact with the load, then concentrated near the prefabricated incision at the bottom, and finally expanded upward. When the specimen was loaded once again after healing, cracks mainly developed from the bottom upward. • The crack-healing ability of asphalt mixture was compared by acoustic emission system. • The peak healing indices of asphalt mixtures were higher than the fracture healing indices. • The healing of the asphalt mixture after forming macrocracks is significantly difficult. • The process of cracking and healing was analyzed according to 3D time difference localization method. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)