Effect of artificial aggregate shapes on the porosity, tortuosity and permeability of their packings

Natural aggregates such as gravel are used in many construction applications for which porous structures are needed, for example to allow water drainage. However, the range of attainable porosities is limited due to the ir-regular shapes of natural aggregates. Here we investigate artificial aggregates of engineered shapes, which allow structures with porosities exceeding 0.7. In this study packings of a variety of artificial aggregate shapes are ex-amined by both numerical and experimental techniques. We can establish a correlation between the porosity of a packing and the sphericity of the aggregates. Furthermore, we confirm that the Carman-Kozeny correlation can be used to predict accurately the permeability of a packing for a wide range of porosities (0.33-0.78). Establish-ment of this basic relationship between the porosity and permeability of a packing is critical for the design of ar-tificial aggregates for novel applications such as energy harvesting from pavements.(c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This study investigates artificial aggregates of engineered shapes that enable structures with high porosities. Numerical and experimental techniques are employed to analyze packings of various shapes of the artificial aggregates. The study establishes a correlation between the porosity of a packing and the sphericity of the aggregates, and confirms the accurate prediction of permeability for a wide range of porosities using the Carman-Kozeny correlation. The establishment of the basic relationship between porosity and permeability in packings is critical for the design of artificial aggregates for novel applications.