Rheological Property of Bitumen Modified by the Mixture of the Mechanochemically Devulcanized Tire Rubber Powder and SBS

The mechanochemically devulcanized ground tire rubber (m-GTR) prepared by solid-state mechanochemical reactor was used in the modification of bitumen with styrene-butadiene-styrene block (SBS) copolymer powder. The conventional properties (such as penetration index, softening point, 5 degrees C ductility, and aging test) and rheological properties of bitumens modified by 8, 10, and 12 wt % m-GTR/SBS were investigated in this paper. The conventional properties except penetration of m-GTR/SBS modified bitumen were improved, compared with 5.5 wt % SBS modified bitumen. Rheological data demonstrated that all of the testing results of 10 wt % m-GTR/SBS modified bitumen were better than those of SBS modified bitumen under the condition of high temperature. The scanning electron microscope observation of the fractured surfaces showed that the m-GTR/SBS mixed powder had a better interface adhesion with matrix than SBS.