Study on low-temperature performance of bitumen, mastic, and asphalt mixture

This research aimed to evaluate the effect of hot mix asphalt components on its low-temperature performance using multiphase analysis. Twelve mixtures, along with corresponding bitumens and mastics were tested with a Bending Beam Rheometer (BBR) at temperatures of -16, -22, and -28 degrees C. A new shift factor, based on creep stiffness master curves, was defined to investigate the relationship between bitumen, mastic, and mixture performance at the reference temperatures of -16 degrees C and -22 degrees C. Results showed that the type of aggregate, bitumen, F/B ratios, and mastic affect the low-temperatures performance of the mixture. The constructed master curves indicated a consistent trend between the low-temperature crack resistance of mastic and the corresponding mixture, although it was observed that a mixture with lower creep stiffness did not necessarily have mastic with lower creep stiffness. A correlation was established between mastic properties and mixture creep stiffness, achieving a 0.9 correlation coefficient for validation data.