Bernal random loose packing through freeze-thaw cycling

Area of Science:

• Granular Materials Science
• Physical Chemistry
• Materials Science

Background:

• Understanding the behavior of granular materials under environmental stress is crucial.
• Freeze-thaw cycles are common natural phenomena affecting material properties.

Purpose of the Study:

• To investigate the impact of freeze-thaw cycling on the packing fraction of granular materials.
• To determine if freeze-thaw cycling can achieve a specific disordered packing state.

Main Methods:

• Experimental study of equal spheres immersed in water subjected to freeze-thaw cycles.
• Numerical simulations to reproduce and analyze the packing behavior.
• Voronoi partition analysis to characterize the structure of the granular packing.

Main Results:

• Packing fraction converges to a stable value (η(∞)=0.595) regardless of the initial state.
• Numerical simulations accurately replicate the experimental observations.
• The granular material reaches a disordered state consistent with random loose packing.

Conclusions:

• Freeze-thaw cycling is an effective method for achieving a specific disordered granular state.
• This process results in a packing fraction corresponding to random loose packing.
• Freeze-thaw cycling offers a soft and spatially homogeneous approach for manipulating granular materials.