沥青抗疲劳性能新型试验与影响因素分析

Evaluation of asphalt fatigue performance using essential work of fracture

为了准确合理地对基质沥青和改性沥青抗疲劳性能优劣做出评价,采用带有数据采集功能的测力延度仪及自制的硅胶模具,对5种不同的沥青进行预制裂纹的双边缺口拉伸实验,以测试沥青在中温延性条件下的疲劳断裂行为。对获得的数据及其影响因素进行理论分析,提出采用裂纹尖端张开位移作为沥青的疲劳性能评价指标。结果表明,沥青的双边缺口拉伸试验可用于对沥青的疲劳性能进行更严格的区分,提出的临界裂纹尖端开口位移反映沥青材料本身中温延性状态下抗撕裂拉伸的能力,更适合作为沥青的疲劳性能评价指标,室内沥青混合料的实际情况也初步验证所提出方法及指标的合理性。

In order to evaluating accurately the matrix asphalt and modified asphalt fatigue performance,used the measure force ductility machine with the function of data acquisition test instrument and homemade silicone mold,the prefabricated crack on five different asphalt were studied by bilateral notch tensile test,tested the fatigue fracture behavior of asphalt under the condition of the medium temperature ductility.Theory analysis was carried out on the obtained data and its influencing factors,put forward using crack tip opening displacement as the fatigue performance evaluation index of asphalt.Test results showed that bilateral notch tensile test can be used as more strict distinction for the fatigue performance of asphalt.The critical crack tip opening displacement reflected the ductile tearing resistance of medium temperature bitumen material itself under tensile ability.As evaluation index for the fatigue performance of asphalt was more suitable,the actual situation of the indoor asphalt mixture was also preliminary verified the rationality of proposed methods and indicators.