Aging and temperature effects on the dynamic characteristics of asphalt mortar under impact loading

Asphalt pavement structures are subjected to impact loading during the milling process. This study aims to investigate the dynamic behavior of asphalt mortar under high strain rates ranging from 281.7 to 830.3 s- 1 through the Split Hopkinson Pressure Bar (SHPB) experiments. The effects of temperature and long-term oven aging on the dynamic properties of asphalt mortar under impact loading were statistically analyzed. The results indicated that the dynamic strength and the impact toughness are both enhanced with the increase in the strain rate and temperature. Laboratory oven aging of asphalt mortar at 85 degrees C for 72 h indicates a significant increase in the carbonyl and sulfoxide indices, a decrease in compressive strength, and rising in elastic modulus. The failure patterns show a strong correlation with the strain rates. An increase in the temperature produces a better gradation of the fragments at higher strain rates regardless of the aging state.