Study on failure mechanism of porous concrete based on acoustic emission and discrete element method

Porous concrete is an environmentally friendly material. To evaluate the damage and discuss the failure mechanism of porous concrete, a uniaxial compression test was carried out in this study. Based on acoustic emission (AE) technology, the changes in AE ringing counts and energy were recorded, and the b-value was analysed. In this research, the evolution of cracks and stress-strain curves of specimens under uniaxial compression were also analysed by the discrete element method (DEM). The results showed that the failure process of porous concrete could be divided into an initial stage, crack propagation stage and failure stage. The mechanical properties and failure characteristics of porous concrete are different from those of conventional concrete. The main failure mode of porous concrete under compression is the failure of the bonding layer between the aggregates, whereas the aggregate failure of conventional concrete rarely occurs. There are many connected or unconnected pores in porous concrete. During the failure process of porous concrete, cracks propagate into the pores until penetrating cracks occur. This paper provides a basis for further study on the microscopic mechanism of porous concrete failure. (C) 2019 Elsevier Ltd. All rights reserved.