CT real-time scanning tests on double cracks propagation under uniaxial compression

Because ceramics is similar to rock in mechanism, ceramics is selected to precut the test specimens with artificial double initial disk-like cracks. The CT real-time scanning tests of the specimens are carried out to study the propagation and damage mechanism of the 3D crack under uniaxial compression. From the comparative analysis of CT values, CT variances and CT images in three different manifold areas, the different propagation laws in areas of up-crack, down-crack and rock bridge are obtained. Firstly, in the up-crack areas, compression and densification are dominant and growth is subordinate; so up-crack has little influence on the damage of the specimen. Secondly, the down-crack propagates greatly, visible wings appear and macro-cracks join together finally, which has great influence on the failure of the specimen. Thirdly, when the center distance between two cracks equals to the 4 times of the crack radius, the propagation process of the crack is related to its parameters; and the interaction between the dual cracks can be omitted.