水对沥青混合料疲劳寿命影响的试验研究

用冻融循环模拟沥青混合料的水损坏状态,采用劈裂疲劳试验分析对比了水对AC-25沥青混合料疲劳特性的影响。研究指标包括:破坏形式差异、疲劳寿命差异、疲劳参数差异以及级配。分析表明:经过1次冻融循环后的破坏劲度模量比未冻融时低约27%;在水损害状态下,沥青混合料的疲劳寿命较普通状态下大为缩短;且沥青混合料试样的疲劳寿命对应力水平更为敏感;沥青混凝土的抗疲劳性能从优到劣的集料级配排序为粗级配、细级配、级配中间值。

Test Study on Water Affection on the Fatigue Performance of Asphalt Pavement

Using the splitting fatigue test and simulating water damage of asphalt concrete via freeze-thaw,we analyzed and compared water damage’s affection on the fatigue performance of asphalt concrete AC-25 in terms of the following aspects: the difference of destroying forms,of fatigue parameters,of graduation. The results show that (i) the failure stiffness module decreased by 27% after one cycle of freezing and thawing,(ii) the fatigue lifespan of asphalt concrete shortened a lot in the water damage condition,(iii)the fatigue lifespan of sample asphalt concrete became more sensitive to stress level, (iv)the anti-fatigue performance of asphalt concrete ranged from the superiority to the inferiority as the follows: coarse grading,fine grading,gradation intermediate value.