The Effect of Filler and Modifier on the Fatigue Characteristics of Road Bitumen

The fatigue characteristics of BND 60/90 grade bitumen, asphalt mastic (AM), modified bitumen (MB), and ternary mixtures (bitumen–filler–modifier) (modified asphalt mastic (MAM)) have been studied. Mineral powder (MP) with a bitumen : MP ratio of 2 : 1 and 1 : 1 has been used as a filler in AM and MAM. Active powder of discretely devulcanized rubber (APDDR) obtained by means of high-temperature shear grinding was used as a modifier in MB and MAM in an amount of 12.5% of APDDR with respect to the weight of bitumen. The positive effect of APDDR exerted on the fatigue life of bitumen and asphalt mastic has been shown. Such fatigue parameters as postpeak pitch angle and τ_max/ \({{\gamma }_{{{{\tau }_{{{\text{max}}}}}}}}\) determined from τ(γ) curves in a linear amplitude sweep test are promising for the ranking of modified samples containing a network of bonds.