温度对RAP填料压缩及渗透特性的影响

Effect of temperature on compression and permeability of RAP fills

针对废旧沥青路面通过再生形成再生沥青路面(recycled asphalt pavement,RAP)材料可作为路堤填料使用,且所含有的沥青成分使其具有温度敏感性和黏滞性的特点,开展不同温度下RAP材料的压缩试验和渗透试验,研究试验温度变化对其压缩和渗透特性的影响规律及作用机制.试验结果表明:在相同击实度下,试验温度高的试样压缩曲线位于温度低的下方,表明在较高温度下试样易于被压实;RAP试样的压缩模量随温度的增加逐渐减小,其压缩性逐渐升高;相同试验温度下,RAP试样在高击实度下的压缩性变化较小,对应的压缩模量变化也较小;RAP试样的渗透系数随试验温度的升高而逐渐增大,其渗透特性可类比于砾石填料.考虑到随着试验温度的升高,RAP材料的压缩性和渗透性相应升高,因此建议在夏季进行RAP填料的路堤施工,以获得较好的压缩特性和渗透特性.

Recycled asphalt pavement(RAP)material formed by regeneration of waste asphalt pavement can be used as embankment fill with temperature sensitivity and viscosity because of the asphalt composition.The effects of temperature on compression and permeability characteristics and the mechanism were investigated by compression tests and permeability tests of RAP samples at different temperatures.The test results show that under the same compaction effort,the compression curve of sample with higher test temperature is below that with lower temperature,which indicates that the sample is easy to be compressed at higher temperature.The compression modulus of RAP sample is decreased gradually with the increasing of temperature,and the compressibility is increased gradually.At the same temperature,the variations of compressibility and the compression modulus for RAP samples under higher compaction effort are relatively small.The permeability coefficient of RAP sample is increased with the increasing of test temperature,and the permeability is comparable to that of gravel as fill.Considering that the compressibility and permeability of RAP materials are increased with the increasing of test temperature,the construction of embankment with RAP fill in the summertime is recommended to obtain better compression and permeability.