不同纤维对SMA路用性能的影响

Influence of different fibers on road performance of SMA

选用3种不同的纤维(木质素纤维、矿物纤维和聚丙烯腈纤维),研究其对SMA混合料路用性能的影响。通过动态剪切流变试验(DSR)及简支梁弯曲蠕变试验(BBR),评价纤维沥青胶浆的技术性能。以SMA-10为例,通过车辙试验及动、静态蠕变试验和恒高度重复剪切试验(RSCH),评价不同纤维对SMA高温性能的影响。结果表明:纤维的加入能够改善沥青混合料的高温性能,同时也降低了沥青混合料的低温抗裂性能,与其他2种胶浆相比,木质纤维胶浆低温性能较差;车辙试验、动态蠕变试验和恒高度重复剪切试验结果具有较好的相关性,能较好地反映不同纤维对SMA高温性能的影响;动态蠕变试验得出的粘弹性常数可以用来进行沥青面层车辙的预估,矿物纤维SMA-10的高温性能好于另外2种纤维;通过4点弯曲疲劳试验,得到不同纤维对SMA疲劳寿命的影响,聚丙烯腈纤维SMA-10的抗疲劳性能最好。

Road performance of SMA（stone mastic asphalt） mixture with three various fibers（lignin fiber,mineral fiber,PAN fiber） are studied.Through the DSR（dynamic shear rheometer） test and the BBR（beam bending rheometer） test to evaluate the technical performance of fiber-asphalt glue,the tests reveal that adding fiber in asphalt can improve the high temperature properties of mixture while its low temperature crack resistance decreased,lignocellulosic asphalt glue＇s low-temperature performance is worse compared with the other two glues.For example of SMA-10,the rutting test,dynamic and static creep tests,RSCH（repeating shear with constant height） test are used to evaluate high-temperature performance of SMA with various fibers.It is pointed that the test results of rutting test,dynamic creep test and RSCH have good correlation,and these results can preferably reflect the influence of various fibers,the riscoelastic constant of dynamic creep test can predict the rutting of asphalt surface,the high-temperature performance of mineral fiber SMA-10 is good compared with the other two mixtures.Through four-points bending fatigue test,it is found that SMA-10 with PAN fiber has the best fatigue property.10 tabs,17 refs.