Fissure Fracture Characteristics of Filling Body with Early Strength Agent Under Different Loading Rates.

Compared with the traditional mining method, the filling mining method has the characteristics of environmental protection and safety, and is widely used in mine production. However, the filling experience in the filling process is affected by internal factors such as cement-sand ratio, gradation, slurry concentration, and external factors such as early strength agent and loading rate. Uniaxial compression test and acoustic emission test were carried out on backfill with and without early strength agent by different loading rates, and the mechanical properties and acoustic emission characteristics were studied. The results show that the strength of the filling body will increase firstly and then decrease under different loading rates, and the strength increase of the filling body is different when the dosage of the early strength agent is different. Based on the acoustic emission characteristic parameters RA and AF, it is found that the proportion of shear cracks decreases with the increase of loading rate, and the shear cracks increase with the increase of loading rate after reaching the critical loading rate. Compared with the filling body with early strength agent, the filling body without early strength agent has more shear cracks generated by loading at the same rate. [ABSTRACT FROM AUTHOR]