Crumb Tire Rubber Polyolefin Elastomer Modified Asphalt with Hot Storage Stability

Compared to styrene-butadiene-styrene copolymer (SBS) as the most used asphalt modifier, polyolefin elastomer (POE) has not been used because of the phase separation during hot storage. The structure and property of POE and POE/crumb tire rubber (CTR) blends modified asphalts were studied by optical microscopy, rheological measurements and aging resistance, respectively. POE particles dispersed irregularly in the bituminous phase below 4 wt% POE, and a continuous POE phase formed over 6 wt%. The screw extrusion and the content of the compatibilizer significantly affected the hot storage stability of the POE/CTR blends modified asphalts. The CTR and POE mutually stabilized in the asphalt by screw extrusion in the presence of glycidylmethacrylate functionalized polymer. The extruded POE/CTR dispersed more finely in the asphalt than controlled POE. The stabilized POE/CTR modified asphalt had better aging resistance than regular SBS modified asphalt.