The Comparison of Static and Dynamic Criteria in Characterizing Rutting Properties of Warm Mix Asphalt Containing Recycled Materials

This paper investigates the effect of recycling of steel slag aggregates (SSA) and reclaimed asphalt pavement (RAP) on the rutting properties of the warm mix asphalt. Nine types of asphalt mix with different combination of SSA and RAP were prepared and underwent static and dynamic creep tests as well as strength deformation test developed by Kim et al. Results showed that the inclusion of SSA into the asphalt mixes improves the rutting resistance; however, the improvements were insignificant in statistical point of view. In contrast, the effect of incorporation of RAP found to be significant by all rutting criteria. However, the mix with 40% coarse SSA and 40% fine SSA had the best rutting performance with 18.3, 36.2, 11.6, and 13.8 percent improvements in rutting criteria in static creep at 100 kPa, static creep at 150 kPa, dynamic creep and Kim tests, respectively. Statistical analysis showed that the dynamic creep and Kim tests had the best reproducibility potential as they offered lower coefficient of variation than other tests. Moreover, results signified that the static creep test at 100 kPa led to poor results in ranking the mixes and had weak correlation with other tests. On the contrary, static creep test at 150 kPa and Kim test exhibited good correlation with dynamic creep test and the ranking of the mixes in these test were consistent.