Abstract: Acoustic emission (AE) will evidently accompany in the process of deformation and grain crushing of the coarse aggregates. Monitoring the acoustic emission signal characteristics of the coarse aggregates under the action of external force can be used to study the crushing mechanism. This paper studies the acoustic emission characteristics of sericite schist coarse aggregates. It uses the coupled acoustic emission large-scale triaxial test apparatus to carry out the conventional consolidated drained triaxial tests, the constant volumetric stress p and the constant deviatoric stress q tests on sericite schist coarse aggregates. The acoustic emission signals are monitored. The test results show that the acoustic emission of coarse aggregates is mainly from the particle breakage, sliding friction and rolling friction. The activities of inter-particle sliding, rolling and particle breakage are severely affected by different confining pressures and different stress levels. So the proportions of frictional AE and fractured AE are different at different stress levels. Under the constant p stress path test, the inflection point of accumulative acoustic emission signals appears, which can judge the strain softening point. The acoustic emission during the constant q test is obviously lower than that during the constant p test. The growth rate of accumulative acoustic emission parameters is gradually increased with the volumetric stress increasing in the constant p test. However, the growth rate of accumulative AE parameters is gradually decreased with the deviatoric stress increasing in the constant q test. It can be deduced that the acoustic emission of coarse aggregates is greatly influenced by shear stress.

Key words: sericite schist coarse aggregate, acoustic emission, stress path, slippage, rolling, particle breakage