Mechanical and Acoustic Emission Behavior of Gangue Concrete under Uniaxial Compression

The application of gangue concrete can be an effective method to solve the massive gangue heap and shortage of raw materials of concrete by replacing the gravel and river sand with crushed gangue. An Acoustic emission (AE) is one of the non-destructive testing methods that can be used for damage detection of the gangue concrete structure. However, there are obvious mechanics differences between gangue and gravel/river sand, so the previous analysis methods of AE signal for concrete structure detection, mainly applied to ordinary concrete, are not suitable for gangue concrete. Based on this, the physical and mechanical characteristics of coal gangue were studied, and the uniaxial compressive test, along with AE monitoring of gangue concrete, was conducted in this paper. The differences in AE behavior between gangue concrete and ordinary concrete were also analyzed. The mechanical test result shows that the compressive strength of gangue concrete can reach 35–40 MPa. Comparing with ordinary concrete, gangue concrete has larger initial porosity and abrupt rupture. Additionally, the accumulative energy growth rate of gangue concrete has two peak values before the peak load, while ordinary concrete only has one. This difference can be used to forecast damage of gangue concrete structure by AE technology. This paper shows the possibility of making concrete by coal gangue, and the possibility of identifying its damage degree with the use of acoustic emission technology.