| As an important building material, asphalt binders have been widely used in roadpavement. Road maintenance and reconstruction had been the primary mission ofroad construction. The recycling of waste asphalt is directly related to the sustainabledevelopment of resources and environment. Asphalt hardens due to aging, andflexibility and fatigue performance of asphalt became worse. According to the theoryof asphalt recycling, waste cooking oil can be used as low viscosity component torecycle aged asphalt. The previous researches have indicated that waste cooking oil ispromising to rejuvenate aged asphalt binders, but no researches were found toinvestigate the effect of waste cooking oil on aged SBS modified asphalt and noresearches were also found to identify shortcomings of waste cooking oil torejuvenate aged asphalt.The objective of this paper is to conduct a laboratory investigation on thephysical, chemical and rheological properties of rejuvenating aged asphalt binderswith waste edible vegetable oil. The materials used for this study included threesources of virgin asphalt (AH-70, AH-50, SBS modified asphalt), three sources ofaged asphalt (virgin asphalt aged by RTFOT and PAV), and waste edible vegetable oilwith five percentages (3.0,4.0,5.0,6.0, and7.0%of aged asphalt). Based on the testresults from types of aged asphalt binders in terms of a series of conventional andspecific tests, the following conclusions can be drawn:(1) The rejuvenated asphalt binders containing6.0%,5.0%,4.0%of waste ediblevegetable oil could respectively improve physical indexes and rheological indexes ofthree aged asphalts of their original asphalt (AH-70, AH-50and SBS modified asphalt)to that of their virgin asphalts. Moreover，through decreasing asphaltenes content andintensity of carbonyl and sulfoxide index of aged asphalts, waste edible vegetable oilhas effect on regenerating aged asphalt, which makes it possible to waste ediblevegetable oil as a regenerator.(2) Waste edible vegetable oil can effectively soften aged asphalt and improvethe fatigue resistance of aged asphalts and decrease fatigue cracking in asphaltmixture. Moreover, a certain dosage of waste edible vegetable oil could improve the ability of temperature susceptibility, aging resistance, rutting resistance, flowdeformation resistance and elastic recovery performance of rejuvenated asphaltbinders. In addition, the excessive addition of waste edible vegetable oil would reducethe rutting resistance, flow deformation resistance and elasticity of rejuvenatedasphalt binders. However, low temperature flexibility, elasticity and thermostabilityof rejuvenated asphalt need to be further improved.(3) There are differences about influence of waste edible vegetable oil onproperties of different ofrejuvenated asphalt, because of differences of degree ofaging and structure composition of different asphalt binders. For example, assumingeach index’s value respectively recovered to the level of that of virgin asphalt, theeffect of waste edible vegetable oil on on different index of one sample and the sameindex of different samples are different.In a word, there is no doubt that waste edible vegetable oil can be used toregenerate aged asphalts. Waste cooking oil asphalt regenerant has important practicalsignificance in protection of ecological environment, sustainable development andresources and energy saving. |
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