Fatigue cracking is an essential problem of
asphalt concrete that contributes to pavement damage. Although stone matrix
asphalt (SMA) has significantly provided resistance to rutting failure, its resistance to
fatigue failure is yet to be fully addressed. The aim of this study is to evaluate the effect of crumb rubber modifier (CRM) on stiffness and
fatigue properties of SMA mixtures at optimum binder content, using four different modification levels, namely, 6%, 8%, 10%, and 12% CRM by weight of the
bitumen. The testing undertaken on the
asphalt mix comprises the dynamic stiffness (indirect tensile test), dynamic creep (repeated load creep), and
fatigue test (indirect tensile
fatigue test) at temperature of 25°C. The indirect tensile
fatigue test was conducted at three different stress levels (200, 300, and 400 kPa). Experimental results indicate that CRM-reinforced SMA mixtures exhibit significantly higher
fatigue life compared to the mixtures without CRM. Further, higher correlation coefficient was obtained between the
fatigue life and resilient modulus as compared to permanent strain; thus resilient modulus might be a more reliable
indicator in evaluating the
fatigue life of
asphalt mixture.