## 2 Materials and Methods
### Laboratory Tests  
The stiffness modulus (resilient modulus) test was carried out to investigate the stiffness of the asphalt mixes. The stiffness modulus of the asphalt mixes was used to describe the characteristics of the asphalt mixes. A universal testing machine (UTM-5P) \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Properties** & **Granite** & **EAF Steel slag** & **Limits** & **Test Basis** \\ \hline Loss Angeles Abrasion (\%) & 22 & 17.80 & \(\leq\)25\% & ASTM C131 [27] \\ Aggregate Crushing Value (\%) & 25 & 22.60 & \(\leq\)25\% & IS: 2386 (Part IV) [28] \\ Density (g/cm\({}^{3}\)) & 2.63 & 3.22 & N/A & ASTM C127 [29] \\ Absorption (\%) & 0.84 & 2.75 & \(\leq\)3\% & ASTM C127 \\ Elongated and Flat Particles (\%) & 8.40 & 3.90 & \(\leq\)10\% & ASTM D4791 [30] \\ Coarse angularity (\%) & 84 & 95 & \(\geq\)80\% & ASTM D5821 [31] \\ Content of free CaO (\%) & - & 1.17 & \(\leq\)4\% & - \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Characteristics of the aggregates. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Sieev Size (mm)** & **Passing (\%)** & **Retained (\%)** \\ \hline
19 & 100 & - \\
12.5 & 95 & 5 \\
9.5 & 85 & 10 \\
4.75 & 60 & 25 \\
2.36 & 43 & 17 \\
1.18 & 33 & 10 \\
0.6 & 26 & 7 \\
0.3 & 20 & 6 \\
0.075 & 5 & 15 \\ Pan & - & 5 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Gradation of the EAF steel slag and granite aggregates. (Inopave Group, Singapore) was utilized to conduct the stiffness modulus test. The stiffness modulus test was carried out in accordance with ASTM D7369 [33]. The test was conducted at two testing temperatures, i.e., 25 \({}^{\circ}\)C and 40 \({}^{\circ}\)C. However, a total of 15 samples with air void contents of 4 \(\pm\) 1% were manufactured for this test. The specimens were conditioned in the environmental chamber for four hours at every testing temperature prior to the test. Thereafter, a load of 1000 N was applied to the specimens. The duration of the applied load with the haversine wave pulse was 0.1 s, while the rest period was 0.9 s.  
To assess the permanent deformation of the asphalt mixes, the dynamic creep test was performed. The test was conducted using a universal testing machine (UTM-5P). The procedures of the dynamic stability test were conducted in accordance with BS DD 226 [34]. To accomplish this test, a total of 30 specimens with air void contents of 4 \(\pm\) 1% were produced. The specimens were kept in the environmental chamber for four hours at the testing temperature of 40 \({}^{\circ}\)C. Thereafter, a stress of 10 kPa was applied for 120 s as a pre-load. Then, the specimens were subjected to different compressive stress i.e., 100 kPa and 200 kPa, for 1 h. The stress was applied with a square wave pulse consisting of 1 s for loading and 1 s for the rest period. The total number of load applications was 1800 cycles. The test of moisture sensitivity was carried out to investigate the resistance to moisture damage of the asphalt mixes. The moisture sensitivity test was conducted according to the procedures stated in AASHTO T 283 [35]. To perform this test, 30 samples were produced. The air void content of the produced specimens was targeted at 7 \(\pm\) 0.5%. Six specimens were manufactured for every mix. Three represented the dry condition, while the rest corresponded to the wet condition. In the dry condition, the specimens were kept in the environmental chamber for at least two hours at a temperature of 25 \({}^{\circ}\)C. Then, the specimens were subjected to an indirect tensile strength. For the wet condition, the samples were exposed to a water saturation of 70-80%. Thereafter, the specimens were conditioned in a water bath for 24 h at a temperature of 60 \({}^{\circ}\)C. Then, the specimens were immersed in the water bath for at least 2 h at a temperature of 25 \({}^{\circ}\)C. Thereafter, every sample was subjected to the applied indirect tensile strength at a constant rate of 50 mm/minute. The tensile strength of the asphalt mix should be higher than 80%.