| Under the influence of external environmental factors,asphalt will be aging,resulting in degradation of road performance,even affecting the safety of traffic in severe cases.The amount of road maintenance projects in our country is increasing day by day,the annual maintenance and milling will produce a large amount of waste asphalt mixtures,which not only pollute the environment,but also waste resources.Nonetheless,if it can be recycled,it will produce a huge economic value.At present,there are few domestic theories about the regeneration of aged asphalt,especially the research on the regular changes and mechanism in the regeneration process of the regeneration components.In this paper,two types of petroleum asphalts(PA-1 and PA-2)were selected to investigate the change law in the aging process,through the asphalt simulating aging experiment,and simulated aging asphalts(OPA-1 and OPA-2)were prepared.And recycled aging asphalt(OPA-3)was obtained by designing waste asphalt mixture recycling experiments;then petroleum,non-petroleum,anthracene oil and other renewable components were added to the three types of aging asphalts for regenerate(RA-1,RA-2,RA-3),and the regeneration effect and matching performance were studied;this paper analyzed the regular changes in the asphalt aging and regeneration process through the softening point,penetration,ductility,anti-aging performance and other indicators.The results show that: during the asphalt aging process,various conventional physical indicators obviously attenuation occurred;for the asphalt regeneration process,RA-1 is good compatibility with aging asphalt and can simultaneously regenerate different performance indicators;RA-2 can improve the secondary anti-aging resistance of recycled asphalt;RA-3 can achieve obvious recovery effect with the least amount of admixture.In this paper,the microstructure of the asphalt samples prepared during the asphalt aging and regeneration process were characterized by group composition analysis,infrared spectroscopy,thermogravimetric analysis,and fluorescence spectroscopy.The results show that the family composition of asphalt changed during the aging process,with the migration of components of small molecular weight to components of large molecular weight and the increase of intermolecular forces;during the regeneration process of asphalt,the asphalt family composition was not restored after incorporating the regenerated components,and no new functional groups were generated,indicating that the regeneration process is based on physical blending,and the effect of restoring the performance of the aged asphalt is achieved by reducing the force between the macromolecules. |
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