  Considering much distresses occurring at the surface of the asphalt roads,
self-healing phenomenon attracted much attention because of reducing the road
surface distresses and its benefits. The use of polymers, which are mainly used
to improve the properties of asphalt mixtures, is one of the ways to increase
self-healing properties. In this study, four polymer-modified bitumen mixtures
were made applying the most common polyurethanes (by combining three different
types of polymers and a nanographene particle). Then the mixtures were exposed
to long-term aging under PAV to be evaluated in situations where less healing
occurs. Finally, by performing a time sweep test and measuring the shear
complex modulus (G *) before and after the rest period, the healing rate of
these mixtures was measured and compared. By examining the results, it was
found that the TDI-CO polymer-modified mixture is the best mixture for bitumen
healing.
