Effect of Waste Edible Vegetable Oil on High Temperature Properties of Different Aged Asphalts

Based on the asphalt rejuvenation theory and some related studies, waste cooking oil can be used for asphalt regeneration. The objective of this study is to investigate the high temperature properties of aged asphalt binder with waste edible vegetable oil. The materials used for this study included three sources of virgin asphalt (60-80 grad, 40-60 grad, SBS modified asphalt), three sources of aged asphalt (virgin asphalt aged by RTFOT and PAV), and waste edible vegetable oil with five percentages (3.0, 4.0, 5.0, 6.0, and 7.0% of rejuvenating asphalt). The high temperature characteristics of these rejuvenated asphalts were tested including viscosity and rutting resistance factor (phase angle and complex modulus). The results indicated that three aged asphalt with an appropriate amount of waste edible vegetable oil can respectively achieve the demand of virgin asphalt in rutting resistance factor, phase angle and complex modulus. It means that waste edible vegetable oil could recover high temperature performance of aged asphalt to the level of original asphalt at a certain amount. Moreover, waste edible vegetable oil can slightly reduce the viscosity value of the aged asphalt and thus decrease the mixing and compaction temperature of the mixture.