## 2 Establishment of the Analysis Model
### Temperature Conditions  
It was assumed that all the structural layers of BRT asphalt pavement were isotropic and completely continuous between layers. The horizontal distribution of the temperature field of the pavement structure was assumed to be unchanged, only heat flux transfer along the depth direction was considered, and the heat flux and temperature between the layers was continuous [44]. The thermal property parameters of each structural layer material of the BRT asphalt pavement were determined by referring to literature [43], as shown in Table 2.  
Because the temperature of the pavement structure changes with time, the temperature field is transient. It is necessary to define steady-state and transient heat conduction analysis steps to analyze the continuous temperature change in one day. User subroutines FILM and DFLUX [45] were programmed in Fortran 77 to simulate the temperature field conditions, including solar radiation, atmospheric temperature and convective heat exchange. The effective radiation of the road surface was defined based on the emissivity of the road surface in the interaction module of the model. Table 3 shows the representative daily 24 h temperature during the hot season in Lanzhou. Table 4 shows the corresponding meteorological parameters. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Structural Layer**} & \multirow{2}{*}{**Material**} & \multirow{2}{*}{**Thickness/ m**} & \multirow{2}{*}{**Density/ (kg\(\cdot\)m\({}^{-3}\))**} & \multirow{2}{*}{**Temperature/ \({}^{\circ}\)C**} & \multicolumn{2}{c}{**Elastic Parameters**} & \multicolumn{2}{c}{**Creep**} & \multicolumn{2}{c}{**Parameters**} & \multicolumn{1}{c}{} \\  & & & & & & & **Dynamic Modulus/** & **Poisson’s** & \(A\) & \(n\) & \(m\) \\  & & & & & & **MPa** & **Ratio** & & & \\ \hline Upper surface layer & \multirow{2}{*}{AC-13} & \multirow{2}{*}{0.04} & & 20 & 10,000 & 0.25 & \(6.54\times 10^{-11}\) & 0.937 & \(-0.592\) \\  & & & & 35 & 3300 & 0.30 & \(3.33\times 10^{-9}\) & 0.862 & \(-0.587\) \\  & & & & 40 & 2400 & 0.35 & \(1.45\times 10^{-8}\) & 0.792 & \(-0.577\) \\  & & & & 50 & 1750 & 0.40 & \(1.39\times 10^{-6}\) & 0.414 & \(-0.525\) \\  & & & & 60 & 1000 & 0.45 & \(1.46\times 10^{-5}\) & 0.336 & \(-0.502\) \\ \hline Intermediate surface layer & \multirow{2}{*}{AC-20} & \multirow{2}{*}{0.05} & & 20 & 11,250 & 0.25 & \(4.58\times 10^{-11}\) & 0.944 & \(-0.596\) \\  & & & & 35 & 3600 & 0.30 & \(2.46\times 10^{-9}\) & 0.796 & \(-0.585\) \\  & & & & 40 & 2720 & 0.35 & \(3.67\times 10^{-8}\) & 0.773 & \(-0.570\) \\  & & & & 50 & 1920 & 0.40 & \(4.80\times 10^{-6}\) & 0.595 & \(-0.532\) \\  & & & & 60 & 1100 & 0.45 & \(7.78\times 10^{-5}\) & 0.384 & \(-0.441\) \\ \hline Lower surface layer & \multirow{2}{*}{ATB-25} & \multirow{2}{*}{0.07} & & 20 & 9000 & 0.25 & \(4.59\times 10^{-11}\) & 0.922 & \(-0.581\) \\  & & & & 35 & 3000 & 0.30 & \(3.46\times 10^{-9}\) & 0.859 & \(-0.576\) \\  & & & & 40 & 2000 & 0.35 & \(1.96\times 10^{-8}\) & 0.830 & \(-0.562\) \\  & & & & 50 & 1300 & 0.40 & \(1.20\times 10^{-6}\) & 0.322 & \(-0.522\) \\ \hline Base & \multirow{2}{*}{\
\begin{tabular}{c} Cement- \\ stabilized \\ soil \\ \end{tabular} } & \multirow{2}{*}{0.30} & & 200 & 20 & 12,000 & 0.25 & - & - & - \\  & & & & & & & \\ \hline Subbase & \multirow{2}{*}{
\begin{tabular}{c} Cement- \\ stabilized \\ soil \\ \end{tabular} } & \multirow{2}{*}{0.30} & & 2100 & 20 & 8000 & 0.25 & - & - & - \\ \hline Subgrade & Soil & 6.00 & 1850 & 20 & 90 & 0.4 & - & - \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Structural and material parameters of BRT asphalt pavement.