| Nowadays,biomaterials derived from biomass resources are economical and environmentally friendly,which has been widely used in pavement engineering.Biorejuvenator based on biomaterials can effectively recycle aged asphalt and restore performance of aged asphalt pavement according to previous study,which may greatly reduce the cost of pavement construction,solve the problem of waste asphalt mixture pollution and realize sustainable development.Therefore,bio-rejuvenator has a wide application prospect.However,as a kind of biomaterials,bio-rejuvenator may possess the characteristic of degradation,which may accelerate the aging process of biorejuvenated asphalt.Thus,it is necessary to study the degradation and aging properties of bio-rejuvenator as well as analyze the aging rule and mechanism of bio-rejuvenated asphalt.At last,the bio-rejuvenator will be modified according to the results of this study and the modified bio-rejuvenator will be applied in the industrial production.Firstly,epoxy vegetable oil was chosen as the raw material for bio-rejuvenator according to the previous research.The viscosity test and flourier transform infrared spectroscopy(FTIR)test were utilized for the samples of bio-rejuvenator after the degradation test and aging test to study whether there was degradation reaction in biorejuvenator and how the properties and chemical components of bio-rejuvenator changed after aging.The results indicated that there was no degradation reaction in biorejuvenator and the bio-rejuvenator was susceptible to age.Afterwards,bio-rejuvenator was used to recycle the short-term aged Pen 70 asphalt and SBS modified asphalt.The aging properties of Pen 70 asphalt,biorejuvenated Pen 70 asphalt,SBS modified asphalt and bio-rejuvenated SBS modified asphalt were studied after the thin film oven test and pressure-aging-vessel test.The results showed that,bio-rejuvenated asphalt was more susceptible to age;network structure formed by SBS modifiers had a great effect on the properties of SBS modified asphalt and the properties of TFOT 15 h aged asphat can be used to predict the properties of PAV aged asphalt.Then,micro-mechanical methods were utilized to study the aging rule and aging mechanism of bio-rejuvenated asphalt.The relationship between aging state,aging speed and aging components was established.The results indicated that the saturated fat aldehyde was the key to the aging of bio-rejuvenated asphalt.Finally,the bio-rejuvenator was modified with anti-aging agent.The tertButylhydroquinone(TBHQ)was the best anti-aging modifier for the bio-rejuvenator and the best dosage was 3%wt.Investigation on the aging properties of the new biorejuvenated asphalt showed that TBHQ improved the anti-aging property of the biorejuvenator and bio-rejuvenated asphalt,and the aging of the saturated fat aldehyde was controlled. |
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