不同废油对老化SBS沥青流变性能的影响

Influence of Different Waste Oils on Rheological Properties of Aged SBS Asphalt

为了探究不同废油对长期老化后SBS沥青流变性能和微观结构的影响,选用厨余油、废生物油、废机油作为再生剂掺入老化SBS沥青中。通过动态剪切流变仪进行了温度扫描、频率扫描、多应力重复蠕变(MSCR)试验、线性振幅扫描(LAS)、弯曲梁蠕变(BBR)试验,对全温度域内再生沥青的流变性能进行了综合评价。采用四组分分析试验与荧光显微镜对不同废油再生SBS沥青的化学组成和微观结构进行了观测,分析了不同废油的再生机理。结果表明:不同废油均能够补充沥青在老化过程中损失的轻质组分,软化沥青,降低沥青硬度与脆性,使得再生沥青高温流变性能和弹性恢复性能低于老化后沥青,且废机油对于老化沥青高温性能的影响最小;不同废油可提升再生沥青的抗疲劳性能,厨余油再生沥青疲劳寿命相比老化沥青提升了110%以上,废生物油与废机油再生沥青的疲劳寿命也高于老化沥青;3种废油再生沥青的低温抗裂性能均有不同程度的恢复,在降低劲度模量的同时蠕变速率增大,废生物油对老化沥青低温性能恢复效果最好,劲度模量相比老化沥青降低了40%;不同废油的再生机理类似,即能够补充老化沥青因热氧作用损失的轻质组分,调节老化沥青的化学组分,改变沥青的胶体结构;废油的加入对老化SBS沥青中降解的聚合物没有明显影响,不能修复断裂的SBS分子。

To explore the influence of different waste oils on the rheological properties and microstructure of long-term aged SBS asphalt,waste cooking oil,waste biooil and waste engine oil are selected as regenerants and mixed into aged SBS asphalt.The rheological properties of recycled asphalt in the whole temperature domain are evaluated by temperature sweep,frequency sweep,multi-stress repeated creep(MSCR)test,linear amplitude sweep(LAS)and bending beam rheometer(BBR)test performed by dynamic shear rheometer.The chemical composition and microstructure of SBS asphalt recycled from different waste oils are observed by four-component analysis test and fluorescence microscope,and the regeneration mechanisms of different waste oils are analyzed.The result shows that(1)Different waste oils can supplement the lost lightweight components during the aging process of asphalt,soften asphalt,reduce the hardness and brittleness of asphalt,and make the high-temperature rheological and elastic recovery properties of recycled asphalt poor than that of aged asphalt,and waste engine oil has the least influence on the high temperature performance of aged asphalt.(2)Different waste oils can improve the fatigue resistance of recycled asphalt.The fatigue life of recycled asphalt from waste cooking oil is increased by more than 110%compared to aged asphalt.The fatigue lives of recycled asphalt from waste bio oil and waste engine oil are also better than that of aged asphalt.(3)The low-temperature cracking resistances of 3 waste oils recycled asphalt are restored to varying degrees.The creep rates increase while reducing the stiffness moduli.Waste bio oil has the best recovery effect on the low-temperature performance of aged asphalt,with a 40%reduction in stiffness modulus compared to aged asphalt.(4)The regeneration mechanism of different waste oils is similar,that is,it can supplement the lightweight components lost by the thermal oxygen action of aged asphalt,regulate the chemical components of aged asphalt,and change the colloidal structure of asphalt.(5)The addition of waste oil has no significant influence on the degraded polymer in aged SBS asphalt and cannot repair broken SBS molecules.