Ageing effects on interfacial bonding properties in asphalt pavements

This study investigated the effects of temperature and aging on the interfacial bonding performance of asphalt pavements using two tack coat materials: cationic modified emulsified bitumen (BCR) and SBR emulsified asphalt. Double-layered specimens were subjected to shear testing at 30°C and 40°C for both aged and unaged conditions. The interface shear modulus (ISM) and peak energy (Epeak) were evaluated to assess interface stiffness and energy absorption. Results indicated that both temperature and aging significantly reduced interlayer shear performance. Aged specimens exhibited approximately 50% lower ISM and Epeak, reflecting weakened bonding due to oxidation and stiffening. While BCR tack coat demonstrated better stability at elevated temperatures, SBR outperformed in energy absorption but showed higher temperature sensitivity. These findings emphasize the need for careful material selection to ensure long-term pavement durability under varying temperature and aging conditions.