Damage pattern recognition of concrete hollow slab with analysis of different AE monitoring positions

Concrete hollow slab has the advantages of simple structure and convenient construction, and is the most widely used structural form in small and medium-span concrete bridges. Recognizing damage patterns is importance for assessing the safety condition of the concrete hollow slabs. This paper adopted the monotonic loading test method of concrete hollow slab to optimize the placement of acoustic emission (AE) sensors of concrete hollow slab, and to identify the AE frequency and damage modes of concrete hollow slab with different damage degree. The research results showed that: the mid-span bottom surface (S2) of the concrete hollow slab was the optimal damage monitoring position for the concrete hollow slab; the AE energy was the most sensitive signal parameter to the damage; The energy of the AE frequency band for cracking and crack propagation of concrete hollow slabs is mainly distributed in 117–195 kHz and 0–78 kHz, respectively; cluster 1 was related to macroscopic crack propagation damage of concrete hollow slab, and cluster 2 was related to microscopic cracking damage.