This paper presents an Acoustic Emission characterisation of the damage behaviour of asphalt concrete subjected to bending fatigue loading. An experimental campaign is carried out on an old asphalt concrete extracted from an in-service highway pavement, built-in 2001. Tests were performed in strain-controlled mode with an amplitude of 175 µstrain, a frequency of 25 Hz, and at 10°C. Failure criteria based on modulus decrease are analysed to determine the fatigue lifespan. Acoustic emission measurements are used to investigate the damage and failure processes. A network of eight piezoelectric sensors was used to acquire the acoustic signals. Therefore, different fatigue stages are identified based on the temporal evolution of acoustic activity. Hence, the event’s spatial location is presented to show the crack path propagation. The results show that sensors located at the bottom of the sample register more acoustic activity. The locations of acoustic events were in good agreement with the mechanical background calculations.

本文介绍了弯曲疲劳载荷作用下沥青混凝土损伤行为的声发射特征。对从内置于2001年使用中的公路路面中提取的旧沥青混凝土进行了实验。在应变控制模式下进行了测试，振幅为175 µstrain，频率为25 Hz，频率为10° C。分析基于模量下降的破坏准则，以确定疲劳寿命。声发射测量用于调查损坏和故障过程。八个压电传感器组成的网络用于获取声音信号。因此，基于声活动的时间演变来识别不同的疲劳阶段。因此，事件的空间位置被呈现出来以显示裂纹路径的传播。结果表明，位于样品底部的传感器显示出更多的声活动。声音事件的位置与机械背景计算非常吻合。