永久性路面面层高掺量橡胶沥青材料路用性能研究

Study on Road Performance of High Content Rubber Asphalt Material for Permanent Pavement Surface Layer

橡胶沥青的路用性能优异,同时橡胶沥青的应用有助于进一步推进废旧轮胎的资源化利用。为满足永久性路面面层材料的高性能需求,助力“双碳”目标,在普通橡胶沥青的基础上进一步提升了橡胶沥青的胶粉掺量,通过预活化和加入裂解剂的方式制备了30%~50%胶粉掺量的橡胶沥青,进而制备了3种级配的沥青混合料,研究了高掺量橡胶沥青及沥青混合料的路用性能。沥青尺度下采用多应力蠕变恢复(MSCR)试验、线性振幅扫描(LAS)试验和弯曲梁流变仪(BBR)试验进行了高掺量橡胶沥青高温抗车辙、抗疲劳和低温抗裂性能评价。混合料尺度下通过车辙试验、四点弯曲疲劳试验、半圆弯曲试验研究了高掺量橡胶沥青混合料的抗车辙、抗疲劳和低温抗裂性能。结果表明:随着胶粉掺量的增加,橡胶沥青及混合料抗车辙性能提升,且由于沥青中弹性成分的增加,导致橡胶沥青应力敏感性增加;橡胶沥青及混合料的疲劳性能随着胶粉掺量的增加而增加,混合料级配对于疲劳性能的影响较小;胶粉的掺加进一步提升了橡胶沥青及混合料的低温性能;高掺量橡胶沥青具有优良的路用性能,且符合永久性路面性能需求及设计理念,基于面层结构的功能需求提出的50%掺量的橡胶沥青适用于路面中、下面层,30%掺量的橡胶沥青适用于路面表面层。

Rubber asphalt has excellent road performance,while the application of rubber asphalt can help further promote the resource utilization of waste tires.In order to meet the high-performance needs of permanent pavement surface layer materials and to help the“double carbon”goal,on the basis of ordinary rubber asphalt,the rubber powder content of rubber asphalt is increased.The rubber asphalt with 30%-50%rubber powder content is prepared by using pre-activating and adding cracking agent,3 types of graded asphalt mixture are prepared,and the road performances of high content rubber asphalt and asphalt mixture are studied.The high temperature rutting resistance,fatigue resistance and low temperature cracking resistance of the high content rubber asphalt are evaluated by multi-stress creep recovery(MSCR)test,linear amplitude sweep(LAS)test,and bending beam rheometer(BBR)test in asphalt scale.The rutting resistance,fatigue resistance and low temperature crack resistance of the high content rubber asphalt mixture are studied by using rutting test,4-point bending fatigue test,and semicircular bending test in mixture scale.The result shows that(1)With the increase of rubber powder content,the rutting resistance of rubber asphalt and mixture is improved,and the stress sensitivity of rubber asphalt is increased due to the increase of elastic component in the asphalt.(2)The fatigue performance of rubber asphalt and mixture increases with the increase of rubber powder content,while the gradation of mixture has little influence on the fatigue performance.(3)The addition of rubber powder further improved the low temperature performance of rubber asphalt and mixture.(4)The high content rubber asphalt has excellent road performance and meets the permanent pavement performance requirements and the design concept.Based on the functional requirements of the surface layer,the rubber asphalt with 50%content is suitable for the middle and lower layers of the pavement,and the rubber asphalt with 30%content is suitable for the pavement surface layer.