| More and more waste tires around the world will lead to a serious environment problemfor it is very difficult to degrade completely. Thus it has become an urgent problem to usethe waste tire effectively. The crumb rubber (CR) powder which generated by waste tire canbe used as asphalt modifier. It has become one of the main ways to deal with the waste tiresby taking waste crumb rubber (WCR) for the modification of the asphalt. The crumb rubberpowder can improve the physical and aging properties, reduce temperature sensitivity, as wellas improve the slip resistance and noise reduction performance of the modified asphalt.However, crumb rubber modified asphalt had some drawbacks in practical application, suchas the lack of comprehensive performance and poor storage stability, which restricts theapplication of waste rubber powder in a certain extent.The organophilic montmorillonite (OMMT)/crumb rubber modified asphalt and thesodium montmorillonite (Na-MMT)/crumb rubber modified asphalt were prepared via themelt blending method. The modified asphalt was characterized by using various techniques,such as the isolation experiment, the rotating thin film oven test (RTFOT), the UV aging test,the UV-vis spectrophotometer, the dynamic shear rheometer (DSR) and by means of XRDandAFM, respectively.The XRD analysis results show that an intercalated structure and exfoliated structuremay be formed in the Na-MMT/crumb rubber modified asphalt and the OMMT/crumb rubbermodified asphalt, respectively. OMMT as well as Na-MMT can increase the softening point,decrease the penetration, decrease the ductility slightly and improve the thermal aging of thecrumb rubber modified asphalt. Compared with Na-MMT, OMMT exhibits a moreremarkable improvement on the physical properties and thermal aging properties of the crumbrubber modified asphalt. The isolation experiment results indicate that OMMT can improvethe high temperature storage stability of the crumb rubber modified asphalt, and Na-MMThad side-effects on the storage stability.AFM observation, UV aging test and rheological properties have been carried out for theOMMT/crumb rubber modified asphalt as OMMT has a better improvement on the physicalproperties and thermal aging properties. AFM images show that the crumb rubber particles have smaller size and more uniform dispersion in the OMMT/crumb rubber modified asphaltdue to the addition of OMMT. The UV aging test indicates that OMMT can improve the UVaging properties of the crumb rubber modified asphalt. Furthermore, OMMT can increase theviscosity of the crumb rubber modified asphalt. The rheological properties were prominent forthe increasing in complex modulus (G*), decreasing in phase angle (δ) and increasing in rutfactor (G*/sinδ) in the OMMT/crumb rubber modified asphalt. |
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