Abstract:In this paper, in order to explore the fracture propagation mode of rubber self-compacting concrete, combined with RA-AF characteristics and Gaussian mixture model, three-point bending test was carried out on semi-circular bending specimens with prefabricated cracks. Rubber content (0 %, 10 %, 20 %, 30 %) and span ratio (0.45, 0.54, 0.72) were selected as test variables to analyze the crack mode and variation of rubber self-compacting concrete. The results show that when the rubber content is 20 %, the rubber self-compacting concrete shows better working performance. With the increase of rubber content, the proportion of tensile cracking AE events increases, indicating that the cracking mode transform into type Ⅰ tensile cracks, and the cracks are continuous. The increase of the span ratio will lead to the decrease of the bearing capacity of the specimen, but the damage degree gradually decreases at the same loading stage, and the fracture mode inside the specimen changes. When the span ratio is 0.54, the specimen shows better working performance. The GMM method shows that the tensile crack AE and the shear crack AE are not simply divided by a straight line, but coexist in some areas. The GMM method can more reasonably describe the variation of the proportion of tensile crack AE events and shear crack AE events under different working conditions.