Research on Strength Prediction Model and Microscopic Analysis of Mechanical Characteristics of Cemented Tailings Backfill under Fractal Theory

In order to further study the internal relationship between microscopic pore characteristics and macroscopic mechanical properties of cemented tailings backfill (CTB), in this study, mine ordinary Portland cement (PC32.5) were selected as aggregate cementing materials, respectively, different additives (anionic polyacrylamide (APAM), lime fly ash) added samples with mass concentration 74% cement–sand ratios 1:4, 1:6 1:8. After 28 days curing, based on uniaxial compressive strength test, nuclear magnetic resonance (NMR) porosity test fractal structure, relationships proportion dimension pores radii analyzed. The prediction model CTB harmless harmful independent variables was established. results show that material are mainly less pores, sum average proportions two reaches 73.45%. Some characterization parameters structure have a high correlation strength. Among them, coefficients 0.9219 0.9049, respectively. regression significant, coefficient is 0.9524. predicted value close actual value, accurate reliable.