动水作用下沥青混合料疲劳性能变化

Reduction of asphalt concrete anti-fatigue performance under hydrodynamic effect

为研究不同材料组成下沥青混合料抗疲劳性能受动水作用的影响,开发了模拟沥青路面受水、荷载、温度共同作用的室内试验设备并提出了试验方法.将6%、10%、14%3种空隙率,AC-16、SMA-16、SAC-16 3种级配,A-90、A-110、A-130 3种沥青组合成7种沥青混合料;对比分析其动水作用前后的应力疲劳方程参数变化.结果表明:7种沥青混合料动水作用后的疲劳性能均有不同程度衰减.疲劳荷载作用下,动水作用后的混合料沥青膜更易剥落.10%空隙率是AC类混合料的较不利空隙率;其疲劳寿命的衰减程度最大且应力敏感性增加.10%空隙率时,悬浮结构沥青混合料抗疲劳性能受动水作用影响要比骨架结构的大,高标号沥青混合料所受影响比低标号的大.

In order to research influences of hydrodynamic effect on asphalt mixture anti-fatigue performance under different material composition,laboratory equipment is developed for simulating the asphalt pavement affected by water,load and temperature. Seven types of asphalt mixture are generated with void ratio of 6%,10% and 14%,gradation of AC-16,SMA- 16 and SAC- 16 and asphalt of A- 90,A- 110 and A- 130; stress-fatigue equation parameters change of these mixture after hydrodynamic effect are analyzed by comparison. The results have shown that anti-fatigue performance of the asphalt mixture is reduced after hydrodynamic effect. Under fatigue load,asphalt membrane of mixture after hydrodynamic effect is easier to spalling. 10% is unfavorable void ratio of AC concrete,it can cause fatigue life reduction and stress sensitivity increase. When the void ratio is 10%,suspension structure of the asphalt concrete follows the larger influence of hydrodynamic effect on anti-fatigue performance than the skeleton structure and high penetration asphalt concrete is larger than low penetration in the influence.