Investigation on blending characteristics in asphalt mixtures with recycled asphalt and waste cooking oil as rejuvenator

Abstract

ABSTRACT Reclaimed asphalt pavement (RAP) mixtures reduces environmental burden by utilising existing pavement material. However, RAP percent is limited due to performance issues at higher RAP content due to improper blending. The degree of blending can be improved using rejuvenator. Waste cooking oil (WCO) is gaining attention as a potential rejuvenator in recycled mixtures. However, past studies have shown contradictory results on WCO influence in asphalt mixture and have not investigated the influence of WCO on blending. This study is devised with a methodological approach to investigate the influence of WCO on blending in asphalt mixtures. Four blending approaches were formulated with four RAP and WCO contents resulting in a total of 148 mixture combinations. The blending characteristics were evaluated by assessing the workability and moisture damage resistance. The optimum mixtures were determined by Grey relational analysis, which were further investigated. The results showed the WCO doses determined from blending equation resulted in the higher dose than optimum WCO. The mixtures with medium dose and dry mixing of WCO showed the highest resistance to moisture damage. Further, for utilising higher than 30% RAP, higher binder content is required as compared to conventional mixture to increase the functional binder in the mixture.