Performance of Warm Mix Asphalt with Recycled Asphalt Mixtures Considering the Effect of Rejuvenating Agent

To expose the effect of rejuvenating agent on performance of warm mix asphalt with recycled asphalt mixtures(WRAM),a laboratory study was conducted to evaluate the performance of WRAM containing three reclaimed asphalt pavement(RAP)(mass fraction are 20%,30%,and 40%,respectively)and three warm mix asphalt(WMA)additives(S-I,DAT,and ET)consisting of surfactant with similar technical properties.Comparative investigation was performed to analyze the performance of WRAM and hot recycled asphalt mixtures(HRAM).The results show that dynamic stability(DS)of WRAM meets the specification requirement no matter whether the rejuvenating agent is used or not.The tensile strength ratio(TSR)and maximum bending tensile strain(em)of WRAM,except that produced using ET and 30%,40% RAP,meet the specification requirements when rejuvenating agent is used.However,TSR of WRAM without rejuvenating agent fails to pass the specification requirements.DS of WRAM with rejuvenating agent exhibits a slight decrease,and it has higher TSR andem values in comparison with that of WRAM without rejuvenating agent when the same WMA additive is used.Among the investigated performance indices of WRAM with the same RAP content,DS,TSR,andemof DAT/WRAM perform best,whereas that of ET/WRAM performs minimum no matter whether rejuvenating agent is used or not.DAT/WRAM exhibits a slight increase,and ET/WRAM displays a distinct decrease as compared to HRAM in terms of the performance indices when rejuvenating agent is used.Moreover,high temperature stability of S-I/WRAM performs slightly lower than that of HRAM,and S-I/WRAM shows similar low temperature cracking resistance and moisture susceptibility to those of HRAM.It has also been shown that rejuvenating agent performs a significant influence on low temperature cracking resistance and moisture susceptibility of WRAM,and there is a considerable difference in performance of WRAM with similar technical properties of WMA additive.