考虑再生剂作用的温拌再生沥青混合料路用性能

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

选择质量分数分别为20%,30%和40%的回收沥青路面材料(RAP)以及具有类似技术性能的3种表面活性类温拌剂(S-I,DAT和ET)制备温拌再生沥青混合料(WRAM),研究了再生剂对温拌再生沥青混合料路用性能的影响,并对WRAM与热再生沥青混合料(HRAM)的路用性能进行了比较分析.结果表明:无论是否使用再生剂,WRAM的动稳定度DS均满足JTG F40—2004《公路沥青路面施工技术规范》的要求;使用再生剂时,添加S-I和DAT型温拌剂的WRAM各项性能均满足规范要求,而添加ET型温拌剂且RAP质量分数为30%和40%的WRAM其最大弯拉应变εm和冻融劈裂拉伸强度比TSR则不满足规范要求;未使用再生剂的WRAM其TSR值不满足规范要求;温拌剂类型相同时,与未使用再生剂的WRAM相比,使用再生剂的WRAM其DS值减小、εm和TSR值均增大;RAP质量分数相同时,无论是否使用再生剂,添加DAT型温拌剂的WRAM其DS,εm和TSR值最大,添加ET型温拌剂的则最小;使用再生剂时,与HRAM的路用性能相比,添加DAT型温拌剂的WRAM路用性能略有提高,添加ET型温拌剂的明显降低,添加S-I型温拌剂的高温稳定性能降低、低温抗裂性能和水稳定性能则与之相近.据此得出,再生剂对WRAM的低温抗裂性能和水稳定性能有显著改善作用,同类型温拌剂对WRAM路用性能的影响亦有显著差别.

To expose the effect of rejuvenating agent on performance of warm mix asphalt with recycled as- phalt mixtures（WRAM）, a laboratory study was conducted to evaluate the performance of WRAM contai- ning 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 tech- nical 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 ra- tio （TSR） and maximum bending tensile strain （εm） 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 rejuve- nating agent exhibits a slight decrease, and it has higher TSR and εm values in comparison with that of WRAM without rejuvenating agent when the same WMA additive is used. Among the investigated per- formance indices of WRAM with the same RAP content, DS, TSR, and εm of 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 mois- ture susceptibility of WRAM, and there is a considerable difference in performance of WRAM with similar technical properties of WMA additive.