环氧沥青混合料的疲劳行为研究

Research on Fatigue Behavior of Epoxy Asphalt Mixture

以美国ChemCo环氧沥青为例,按马歇尔设计方法进行了混合料设计,利用万能材料试验机MTS-81完成疲劳试验,并对沥青混合料小梁力学特性进行了检测,从沥青用量、摊铺等待时间、应力比3个影响因素,分析了环氧沥青混合料疲劳性能的变化规律,并回归了环氧沥青混合料的疲劳行为方程。结果表明：疲劳寿命与沥青用量、摊铺等待时间、应力比3个影响因素的关系分别为：随应力比增大而减小,随沥青用量的增大而增大,越过某个特定的时间点之后随摊铺等待时间的增大而减小,疲劳寿命的以10为底的对数分别与3个因素呈幂函数、指数和指数关系;提出多维拟合后的疲劳行为预估方程;并经过验证,此方程的适用范围限于应力比在0.3~0.7以内,沥青用量在5%~8%以内,以及摊铺等待时间在0~120 min以内。

Taking American Chem Co epoxy asphalt mixture for example,the mixture was designed according to the Marshall Design method. The fatigue test was completed by universal material testing machine MTS-81 and the beam mechanic characteristics of asphalt mixture were tested. The variation law of fatigue performance of epoxy asphalt mixture was analyzed from 3 influence factors,including asphalt content,paving waiting time and stress ratio. Finally,a fatigue behavior equation of epoxy asphalt mixture was regressed. The results show that the relationship between the fatigue life and asphalt content,paving waiting time and stress ratio three factors is as follows： fatigue life decreases when the stress ratio increases; it increases when the asphalt content increases; it decreases when the waiting time increases after passing a particular time point. The logarithm of the fatigue life taking 10 as bottom presents as a power function,index and index relationship with the three factors respectively. The equation turns out after multi-dimensional fitting. Through verification,the equation can be applied when the stress ratio is between 0. 3 ~ 0. 7,the asphalt content is between 5% ~ 8% and the paving waiting time is within 0 ~ 120 min.