Trans-scale relationship analysis between the pore structure and macro parameters of backfill and slurry

Area of Science:

• Geotechnical Engineering
• Materials Science
• Fractal Geometry

Background:

• Backfill's porous structure dictates its mechanical properties and slurry flowability.
• Understanding multiscale mechanics requires characterizing pore structure and its link to macro parameters.

Purpose of the Study:

• Quantify backfill pore structure using fractal theory and image analysis.
• Establish relationships between pore fractal dimension and macro parameters (flowability, mechanical strength).
• Investigate the influence of microstructure on macro-scale behavior.

Main Methods:

• Analysis of scanning electron microscopy images using OTSU and box counting methods.
• Calculation of the fractal dimension of the backfill pore structure.
• Quantitative characterization of pore structure and correlation analysis with macro parameters.

Main Results:

• Fractal dimension effectively characterizes the complexity of backfill's pore structure.
• Negative correlation found between pore fractal dimension and slurry's equilibrium shear stress (ESS) and equilibrium apparent viscosity (EAV).
• Positive correlation between backfill's uniaxial compressive strength (UCS) and flowability parameters; negative correlation with fractal dimension.
• Established linear correlations: fractal dimension vs. UCS (R²=-0.638) and fractal dimension vs. water content (WC) (R²=0.604).

Conclusions:

• Fractal dimension serves as a reliable indicator of pore structure complexity.
• Pore fractal dimension can predict key macro parameters like UCS and WC.
• Microstructure significantly influences macro-scale properties, enabling prediction through pore structure analysis.