Quantitative evaluation of low-temperature performance of sustainable asphalt pavements containing recycled asphalt shingles (RAS)

• The results supported the use of RAS modified mixtures in warm climates.
• The warmer embrittlement temperatures due to RAS is critical in cold climates.
• Nodules of RAS form due to partial blending between the RAS and virgin binders.
• RAS nodules accumulate damage first and thus govern the embrittlement temperature.
• Higher RAS content leads to higher peak loads and lower fracture energy in DC(T) test.

The low-temperature cracking characteristics of asphalt concrete materials containing varying amounts of recycled asphalt shingles (RAS), 0–12.5%, and mixed at three different temperatures are investigated using the Disk-shaped Compact Tension (DC(T)) and acoustic emission (AE) tests. The specimens’ AE activities were monitored during cooling from room temperature to −50 °C to determine their embrittlement temperatures. It was observed that the mixtures containing RAS had lower DC(T) fracture energies, higher DC(T) peak loads, and warmer embrittlement temperatures than the control mixture. Results also showed that higher mixing temperatures appear to lower embrittlement temperatures for mixtures containing RAS.