Abstract: In order to understand the influence of the disturbance during setting and hardening period on concrete damage, the simulated disturbance test was carried out on the concrete in the initial setting stage to the final setting stage, and the acoustic emission signals generated during the compression failure process of the disturbed concrete were collected. By comparing the acoustic emission characteristic parameters of different specimens, the acoustic emission characteristics of concrete with different disturbed ages under the uniaxial compression were studied. Based on the formation dynamics of cement concrete structure, the damage mechanism of disturbed concrete was analyzed. The results show that the disturbance causes damage to concrete in different degrees. The disturbance in the middle stage of setting and hardening has a great influence on the performance of concrete, which reduces the peak stress of concrete by 25.1%, and the damage degree reaches 14.2%. The disturbance near initial setting and final setting has little effect on concrete. Compared with the reference concrete, the acoustic emission energy release rate of the disturbed specimen is smaller at the initial stage of loading, and the active range of acoustic emission appears in the later stage of loading. When the relative stress level is less than 50%, there is no obvious emission signal. The acoustic emission rate parameter a is the smallest and the process parameter b is the largest.

Key words: concrete, setting and hardening period, disturbance, acoustic emission, damage