Preparation And Properties Of Rejuvenator For SBS Modified Bitumen

SBS modified bitumen mixture has been widely used to the high-grade highwaysconstruction. Although SBS modified bitumen come into aging in the condition ofenvironment factors which result in many diseases, it will produce amount of wasteSBS modified bitumen mixture to repair and maintenance the road. To protect theenvironment and save the natural resources, the waste SBS modified bitumen mixtureneeds to be recycled which is an important work in the development of bitumenpavement. According to experience, the most effective way to recycle the SBSmodified bitumen mixture is using rejuvenator, existing rejuvenator aim at basebitumen mixture, so it can restore the performance of the base bitumen mixture, butcannot restore the aging SBS modified bitumen. The aging of SBS modified bitumenis different to base bitumen, the aging of SBS modified bitumen also refers to theaging of SBS, so the SBS modified bitumen rejuvenator not only needs to restore thebitumen but also the aging SBS thus restoring the performance of aging SBS modifiedbitumen. This paper adopt FCC oil, base bitumen and epoxy functional groupscompound to prepare SBS modified bitumen rejuvenator, the physical properties,aging properties and rejuvenating properties of epoxy functional groups reactiverejuvenator were studied and the influence of the content of epoxy functional groupsreactive rejuvenator to the aging SBS modified bitumen was also studied, thechemical construction and distribution of SBS before and after aging were tested byFourier Transform Infrared Spectroscopy (FTIR) and fluorescence microscope, mainconclusions are as follows:(1) In this paper, the base bitumen, FCC oil and epoxy functional groupscompound were used to prepare the reactive rejuvenator which can meet the relatedrejuvenator specification and can restore the properties of the aging SBS modifiedbitumen.(2) The three kind of reactive rejuvenator can restore the viscosity, penetrationand ductility of aging SBS modified bitumen. The difference is that the restoring ofductility is different, the single epoxy functional groups reactive rejuvenator (SR) anddouble epoxy functional groups reactive rejuvenator (SDR) can restore the ductility ofaging SBS modified bitumen from1.2cm to15cm and20cm, but the more epoxyfunctional groups reactive rejuvenator (SDTR) can restore the ductility to26cm.(3) SDTR has better regeneration effect to both aging SBS modified bitumen and the aging mixed with fresh SBS modified bitumen. The viscosity of rejuvenating SBSmodified bitumen decrease with the content of epoxy functional groups reactiverejuvenator and the penetration increase. The epoxy functional groups reactiverejuvenator can restore the aging SBS modified bitumen with the content of11%andto the aging mixed with fresh SBS modified bitumen, the content is9%. With theaddition of reactive rejuvenator, the viscosity of aging SBS modified bitumendecrease and the penetration increase.(4) DSR test reflects that reactive rejuvenator can decrease the complex modulusand increase the phase angle of aging SBS modified bitumen, restoring theviscoplastic property of aging SBS.(5) The results of FTIR reflect that the C=C group relative amount decrease andthe C=O group relative amount increase after aging, the reactive rejuvenator canincrease the C=C group relative amount and decrease the C=O group relative amount.The epoxy functional groups react with the groups which is reactive at the end of thetwo SB molecule, making the diblock SB turn into triblock SBS by molecular chaincoupling, thus restore the construction of SBS. Fluorescence microscope analysisfurther confirmed this result.