动水作用下沥青混合料疲劳性能变化

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.

Reduction of asphalt concrete anti-fatigue performance under hydrodynamic effect

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.