Worldwide, asset managers are struggling with the management of ageing infrastructure in reinforced concrete. Early detection of reinforcement corrosion, which is generally considered as the major problem, can help to perform dedicated maintenance and repair. The acoustic emission technique is promising to reach this goal. However, research on the characterisation of the different damage sources during corrosion in reinforced concrete remains scarce. In this article, the characterisation of damage processes is investigated on small reinforced concrete prisms and upscaled to reinforced concrete beams under accelerated conditions in a laboratory environment. Damage sources are assigned based on careful validation with crack width measurements and dummy samples. Signals originating from different acoustic emission sources are compared in the time and frequency domain. Moreover, the continuous wavelet transform is applied to provide information on time–frequency characteristics. The results show that the moment of concrete macro-cracking can be derived from a sudden increase of the cumulative acoustic emission events and cumulative acoustic emission energy. However, validation with crack measurements is required. The shift in both peak and centre frequency of the acoustic emission signals is found to be a better indicator. Wavelet transform allows to distinguish acoustic emission sources when frequency ranges are overlapping. Possible acoustic emission sources such as the corrosion process and concrete cover cracking, are successfully assigned. The major contributions of this article are the characterisation of acoustic emission sources from corrosion damage in reinforced concrete, validation with crack measurements and dummy samples, as well as a dedicated wavelet analysis.

在全球范围内，资产管理公司都在努力管理钢筋混凝土中老化的基础设施。通常被认为是主要问题的钢筋腐蚀的早期检测有助于进行专门的维护和修理。声发射技术有望实现这一目标。然而，关于钢筋混凝土腐蚀过程中不同损伤源表征的研究仍然很少。在本文中，在实验室环境中的加速条件下，研究了小型钢筋混凝土棱柱上的损伤过程表征，并放大到钢筋混凝土梁。损伤源是根据裂纹宽度测量和虚拟样品的仔细验证来分配的。来自不同声发射源的信号在时域和频域中进行比较。此外，连续小波变换用于提供有关时频特性的信息。结果表明，混凝土宏观开裂的时刻可以由累积声发射事件和累积声发射能量的突然增加推导出来。但是，需要通过裂纹测量进行验证。发现声发射信号的峰值和中心频率的偏移是更好的指标。当频率范围重叠时，小波变换允许区分声发射源。成功地分配了可能的声发射源，例如腐蚀过程和混凝土覆盖层开裂。