Time-Dependent Rheological Properties of Cemented Aeolian Sand-Fly Ash Backfill Vary with Particles Size and...

Area of Science:

• Geotechnical Engineering
• Materials Science

Background:

• Underground coal mining causes surface subsidence, addressed by backfilling with cemented Aeolian sand-fly ash backfill (CAFB).
• The rheological performance of CAFB, especially with overflow water and strength loss, requires further understanding.
• Limited research exists on the impact of aeolian sand and coal gangue on CAFB rheology with plasticizers.

Purpose of the Study:

• To investigate the effects of a plasticizer on the rheological properties (yield stress and viscosity) of CAFB.
• To analyze CAFB prepared with aeolian sand and coal gangue.

Main Methods:

• Preparation of CAFB mixes with varying plasticizer concentrations (0%, 0.05%, 0.1%).
• Determination of yield stress and viscosity at different time intervals.
• Conducting thermal analysis and zeta potential analysis.

Main Results:

• Rheological properties of CAFB are a composite of various factors.
• Optimal particle size distribution and low plasticizer content stabilize slurry structure.
• Reduced slurry settlement and lower risk of pipe blockage were observed.

Conclusions:

• Plasticizer content significantly influences CAFB rheology.
• Careful control of particle size and plasticizer is crucial for stable CAFB.
• Findings aid in designing and producing effective CAFB materials for mining subsidence control.