Abstract:
To study the effects of aging on the fatigue properties of warm-mixed crumb rubber asphalt mixture (WMA) and hot-mixed crumb rubber asphalt mixture (HMA), a three-point bending fatigue test was carried out on semi-circular WMA and HMA specimens. With the images collection through Digital image correlation method (DSCM) and calculation average horizontal strain
εxa, the effect of aging on fatigue cracking was studied by the curve of
εxa with cyclic loading times
N. Results show that
εxa can be adopted to study the fatigue cracking characteristics of asphalt mixture and the fatigue crack create when
εxa plunges. Before the peak strain, the curve of unaged HMA and WMA was linear with
N, while the curve was concave after aging. After aging, the anti-deformation ability of HMA and WMA was enhanced, and the anti-cracking performance became worse. WMA has better anti-cracking performance than that of HMA. As the aging degree increases, the main fatigue cracking forms of HMA and WMA change from viscoelastic destroy to brittle destroy.