On the Acoustic Emission Characteristics of Concrete Fracture Subjected to Three-Point-Bending
混凝土材料三点弯曲破坏的声发射特性

In order to study acoustic emission signal characteristics of gravel concrete materials under different stress states, three-point-bending test of concrete beam was carried out on a MTS testing machine, and advanced multi-channels acoustic emission system was used to detect the fracture process of concrete beams subjected to three-point-bending loading. Concrete material fracture process may be divided into seven kinds based on filtering the signal emission duration, the counts and the hit numbers. According to the results of former experimental study about concrete material Kaiser effect, it was indicated that different kinds of acoustic emission signal corresponded to different relative stress levels. Results show that emission duration, counts and hit number of acoustic emission signals can not only characterize the concrete failure process types, but also characterize the concrete stress state. It provides a new way for on-line monitoring concrete material.