Abstract The detection of incipient and minor cracks in prestressed reinforced concrete (RC) structures is crucial in ensuring safety of existing bridges. However, traditional structural health monitoring (SHM) often fails to provide reliable and effective early detection. As a matter of fact, literature SHM applications typically investigated moderate-to-severe cracking conditions and often developed criteria that are likely to depend on investigated scenarios. Aiming at addressing the abovementioned literature gap, this study evaluates the effectiveness of acoustic emission (AE) testing for early crack identification in post-tensioned RC girders. AE tests are carried out during cyclic and monotonic four-point bending tests on different specimens up to failure. Multiple AE analysis methods are systematically implemented considering literature methods and novel method specifications (MSs). The evolution of key AE features is examined, and several indicators are further analyzed through a blind assessment framework. The complete AE dataset of AE data is made publicly available. AE activity trends and their potential correlation with observed mechanical damage are identified and discussed. Among the investigated indicators, relative acoustic entropy shows particular promise for early crack detection. The study systematically compares the application of multiple assessment methods, identifying strengths and weaknesses and outlining potential SHM criteria. The findings demonstrate that AE testing, when combined with suitable MSs and damage criteria, offers a viable path for reliable SHM. This paper lays the groundwork for development of robust damage detection criteria.
D’Angela et al. (2026) studied this question.