Abstract
This paper focuses on the effect of packing conditions and materials properties on loose packing fraction of particles from theoretical and experimental perspectives. First, the difference in loose packing of particles was measured in different conditions. In the second part, we obtained the main factor that dominated the loose packing fraction in different particle scales. We concluded that kinetics energy induced by the gravitational potential energy almost has no influence on the loose packing fraction for particles smaller than a few millimeters. On the contrary, the wall effect became more and more evident with the increase of particle size. Particle morphology and PSD significantly affect the loose packing of particles above the sub-millimeter size. Moreover, for micron-sized particles, the Van der Waals force was shown to dominate all other colloidal interactions, and the ratio between Van der Waals force and effective gravity determined the loose packing fraction of fine powders.
Acknowledgments
The authors gratefully acknowledge the National Natural Science Foundation of China (no. 51890904, no. 52022022) and the Fundamental Research Funds for the Central Universities (2242020R40086). Furthermore, greatly appreciate the Jiangsu Research Institute of Building Science Co., Ltd. and the State Key Laboratory of High-Performance Civil Engineering Materials for funding the research project.
Disclosure statement
The authors declare that they have no conflict of interest.