Effects of Normal Stress on Shear Properties and Acoustic Emission Characteristics of Bonded Rock-Concrete Interfaces

Abstract

Laboratory direct shear and acoustic emission tests are conducted on standard cylinder specimens with varying levels of normal stress. The aim is to gain a better understanding of shear behavior and failure mechanisms of the bonded interface. The results show that increasing of normal stress enhances the brittleness of the specimens. In addition, the test shows that the failure degree of specimens increases with the different normal stresses. The test results show that high amplitude AE peak energy and count generation occur when the specimens reach the peak shear stress. Meanwhile, with the increase of normal stress, the cumulative acoustic emission energy before peak stress increases slightly, but the cumulative acoustic emission count before peak stress decreases. AE b-value proves to be an effective parameter for reflecting the crack size and main crack surface of rock-concrete specimens. The fluctuation value of the AE-b value is influenced by the normal stress.