## Appendix B Test Methods of Asphalt Mixture  
1. Rutting test Dynamic stability (DS) could be calculated according to Equation (A1). \[\text{DS}=\frac{(t_{2}-t_{1})\times N}{d_{2}-d_{1}}\times C_{1}\times C_{2}\] (A1) where: DS is the dynamic stability of test specimen (times/mm); \(t_{1}\) and \(t_{2}\) are test time (minute); \(d_{1}\) and \(d_{2}\) are rutting depth at \(t_{1}\) (mm) and \(t_{2}\) (mm); \(C_{1}\) is the correction factor of the wheel tracking apparatus, and its value is 1.0 in this test; \(C_{2}\) is the coefficient of compacted specimen, and its value is 1.0 for 300 mm width specimen; \(N\) is wheel speed, 42 times/min in this test.
2. Vacuum saturated Marshall stability test: Original splitting strength (\(R_{\text{T1}}\)) and freeze-thaw splitting strength (\(R_{\text{T2}}\)) were calculated as Equations (A2) and (A3): \[R_{\text{T1}} =0.006287P_{\text{T1}}/h_{1}\] (A2) \[R_{\text{T2}} =0.006287P_{\text{T2}}/h_{2}\] (A3)where: \(R_{\rm T1}\) (Original splitting strength) is the splitting tensile strength of first set of individual specimen without freeze-thaw cycles (MPa); \(R_{\rm T2}\) (freeze-thaw splitting strength) is the splitting tensile strength of second set of individual specimen subjected to freeze-thaw cycles (MPa); \(P_{\rm T1}\) is the test load values of first set of individual specimen (N); \(P_{\rm T2}\) is the test load values of second set of individual specimen (N); \(h_{1}\) is the height of first set of individual specimen (mm); \(h_{2}\) is the height of second set of individual specimen (mm). Tensile strength ratio (TSR) was calculated based on Equation (A4): \[{\rm TSR}=\frac{\overline{R}_{\rm T2}}{\overline{R}_{\rm T1}}\times 100\] (A4) where: TSR is tensile strength ratio (%); \(\overline{R}_{\rm T2}\) is the mean value of splitting tensile strength of second set of effective specimens subjected to freeze-thaw cycles (MPa); \(\overline{R}_{\rm T1}\) is the mean value of splitting tensile strength of first set of effective specimens without freeze thaw cycles (MPa).
3. Freeze-thaw splitting test: Residual stability of vacuum saturated Marshall stability test was calculated based on Equation (A5): \[{\rm MS}^{\prime}_{0}=\frac{{\rm MS}_{2}}{{\rm MS}}\times 100\] (A5) where: \({\rm MS}^{\prime}_{0}\) is the residual stability (%) of specimen; \({\rm MS}_{2}\) is the stability of vacuum saturated specimen after immersed in water for 48 h (kN); MS is the stability of specimen (kN).
4. Low-temperature bend test: Flexural tensile strength, ultimate tensile strain and bending stiffness modulus were calculated based on Equations (A6)-(A8). \[R_{\rm B}=\frac{3\times L\times P_{B}}{2\times b\times h^{2}}\] (A6) \[\varepsilon_{\rm B}=\frac{6\times h\times d}{L^{2}}\] (A7) \[S_{\rm B}=\frac{R_{B}}{\varepsilon_{\rm B}}\] (A8) where: \(R_{\rm B}\) is flexural tensile strength when the test specimen failed (MPa); \(\varepsilon_{\rm B}\) is ultimate tensile strain when the test specimen failed (\(\mu\varepsilon\)); \(S_{\rm B}\) is bending stiffness modulus when the test specimen failed (MPa); \(b\) is the width of test specimen (mm); \(h\) is the height of test specimen (mm); \(L\) is the span of test specimen (mm); \(P_{B}\) is the maximum load when the specimen failed (N); \(d\) is the bending of test specimen in the middle of the span (mm).
5. Skid resistance test (Sand patch method): The texture depth of asphalt mixture was calculated based on Equation (A9), accurate to 0.01 mm. \[{\rm TD}=\frac{100\times V}{\pi\times D^{2}/4}=\frac{31831}{D^{2}}\] (A9) where: TD is the texture depth of asphalt mixture (mm); V is the volume of sand, 25 cm\({}^{3}\); \(D\) is the average diameter of sand patch (mm).