寒区再生集料水泥稳定碎石路基的力学和温缩性能

Mechanical and temperature shrinkage properties of recycled aggregate cement stabilized macadam subgrade in cold regions

为解决废旧沥青混合料(RAP)和铁尾矿砂(ITS)固废处理问题,将两者充当砂石料掺加到水泥稳定碎石中,通过无侧限抗压试验、弯拉试验和温缩试验对水泥稳定碎石进行路用性能研究,分析了RAP和ITS掺量对水泥稳定碎石的影响。结果表明:RAP掺量一定时(25%),ITS掺量增加有利于提高水泥稳定碎石的抗压强度和弯拉强度,但会增大材料的温缩应变和温缩系数,降低温缩性能,其中ITS45(ITS掺量为45%)有较好的温缩性能;ITS掺量一定时(60%),RAP掺量增加不利于水泥稳定碎石的抗压强度,但可以提高水泥稳定碎石的弯拉强度,降低温缩应变和温缩系数,其中RAP70(RAP掺量为70%)温缩性能达到最优;与ITS45相比,RAP70有更宽泛的施工温度区间。

To study the problem of reclaimed asphalt pavement(RAP)and iron tailing sand(ITS),they are added to cement stabilized macadam as gravel and sand. The road performance of cement stabilized macadam is studied through unconfined compressive test,flexural-tensile test and temperature shrinkage test,and the effects of RAP and ITS content on cement stabilized macadam is analyzed. The results show that:When RAP content is fixed(25%),the increase of ITS content is beneficial to improve compressive strength and flexural-tensile strength of cement stabilized macadam,but it will increase temperature shrinkage strain and temperature shrinkage coefficient of the material,and reduce temperature shrinkage property. Among them,ITS45(ITS content is45%)has better temperature shrinkage performance. When ITS content is fixed(60%),the increase of RAP content will not be conducive to compressive strength of cement stabilized macadam,but it can increase flexuraltensile strength,and reduce temperature shrinkage strain and temperature shrinkage coefficient. Among them,RAP70(RAP content is70%)has the best temperature shrinkage performance. Compared with ITS45,RAP70 has a wider construction temperature range.