## 1 Introduction
[16] studied the impact of short-term aging on the cracking resistance of asphalt mixture using the SCB test (\(-10\)\({}^{\circ}\)C to \(-22\)\({}^{\circ}\)C). It was demonstrated that the short-term aging asphalt mixture exhibited a superior cracking resistance to that of the mixture under unaging conditions at a lower test temperature, which was captured by the elevation in the surface free energy of the asphalt binder caused by aging. As described in the above literature, a majority of the current experimental research on cracking resistance that considers different degrees of aging is limited to low or medium temperatures. However, cracking can also occur at high temperatures [17]. Therefore, it is necessary to test cracking resistance at high temperatures. Even so, it is worth noting the cracking resistance of asphalt mixture considering a high temperature (30 \({}^{\circ}\)C) was only reported in one study [13]. As the highest temperatures can reach about 40 \({}^{\circ}\)C in most parts of southern China, it seems that the highest test temperature should be set at 40 \({}^{\circ}\)C instead. Furthermore, as asphalt mixture is a kind of multi-phase composite material, its overall mechanical properties are bound to be associated with its internal structure, such as its gradation. On this basis, a few studies have been launched to probe the effect of gradation on the cracking resistance of asphalt mixture. [PERSON] et al. [18] employed the SCB test at different test temperatures below 0 \({}^{\circ}\)C on both continuous gradation and gap gradation asphalt mixtures (AC-16, SMA-16, AC-20). Additionally, test results were more influenced by gradation than test temperature. [PERSON] et al. [19] conducted an indirect tension low-temperature creep test (0 \({}^{\circ}\)C, 10 \({}^{\circ}\)C, and \(-20\)\({}^{\circ}\)C) on AC-20 with different gradations (coarse, medium, and fine). It was revealed that medium gradation showed the best cracking resistance at 0 \({}^{\circ}\)C, medium gradation at \(-10\)\({}^{\circ}\)C, and coarse gradation at \(-20\)\({}^{\circ}\)C.  
There are five main types of indoor evaluation method for the cracking resistance of asphalt mixture: semi-circular bending test, indirect tension test, trabecular bending test, disk shaped compact tension test [20; 21] and direct tension test. Among them, the direct tension test is simpler regarding the specimen preparation as well as loading mode, more direct regarding the stress-strain data acquisition and better regarding the reflection of actual stress state of the asphalt mixture. Therefore, it is more suitable to be employed than the other four test methods [22; 23; 24]. As mentioned in the literature review, however, only the direct tension test was reported [3]. In terms of evaluation indexes, tensile strength, peak deformation, and modulus are most widely used. Nevertheless, [PERSON] et al. [25] believed that conflicting conclusions could be drawn based on the three indexes mentioned above, and a single tensile strength index and failure strain sometimes cannot fully reflect the cracking resistance of the asphalt mixture. Based on this situation, [PERSON] et al. [26] evaluated the cracking resistance by calculating the strain energy density. The result showed that the cracking resistance decay rate of the asphalt mixture prepared by the oven heating method was equivalent to that prepared by the delayed mixing method. Furthermore, [PERSON] [27] revealed that it is difficult to judge the cracking resistance of asphalt mixture using only the fracture energy index and established a more comprehensive evaluation index by determining the weight of each index through the analytic hierarchy process (AHP). However, the weight definition is susceptible to the decision-makers' preference for the AHP method, leading to less convincing evaluation results.