橡塑沥青混合料疲劳性能测试及预估模型研究

Fatigue performance research of stabilized rubber and plastic modified asphalt mixture

橡塑改性沥青混合料作为一种新型路用材料,在提高路面性能的同时实现废料的循环利用,沥青混合料的疲劳性能与沥青路面的损坏机理密切相关,开展其疲劳性能的研究具有重要意义。文章旗于应变控制模式下的四点弯曲疲劳试验来研究稳定型橡塑改性沥青混合料的疲劳性能,选取SMA-13级配,设计了不同条件下的测试方案,分析了应变水平、空隙率及沥青含量对混合料疲劳性能的影响,并对所选择的疲劳预估模型进行了修正。结果表明:稳定型橡塑改性沥青混合料的疲劳寿命随着沥青含量的增加、空隙率的降低以及应变水平的减小而增加;修正后的疲劳预估方程可以较为精确的预测其疲劳寿命,验证结果和预测结果的相关性系数达0.915。

The rubber and plastic modified asphalt mixture as a new type of road material, in the view of improving the performance of pavement and achieving the recycling waste, the fatigue performance of asphalt mixture and the asphalt surface damage mechanism are closely related, to study the fatigue performance is of great significance. Based on strain mode stable four-point bending fatigue test research of fatigue properties of the stabilized rubber and plastic modified asphalt mixture, by selecting the SMA-13 grading, the test method was designed under different conditions, then the influence of strain level, air voids and asphalt content on the fatigue life of the mixtures was analyzed. Based on the fatigue test results, a modification was performed on a predicting equation. The results show that the fatigue life of the stabilized rubber and plastic modified asphalt mixture increases with the increase of asphalt content and the decrease of air voids and strain level and that the modified equation gives a good result on predicting the fatigue life of stabilized rubber and plastic modified asphalt mixture.