A 3-parameter packing density model for angular rock aggregate particles

• Particle shape has certain effects on the packing density of particles.
• Such effects are studied experimentally using angular rock aggregate.
• The 3-parameter model is extended for application to angular rock aggregate.
• The extended model is verified by comparing to experimental results.

The authors have in recent studies incorporated the wedging effect to develop a 3-parameter model for packing density prediction of binary and ternary mixes of spherical particles. This model has been restricted to only spherical particles because only the test results of spherical particles were used for derivation and validation. For more general applications to other types of particles, such as angular particles, the model needs to be further developed. In this study, an experimental program on the packing density of binary mixes of angular rock aggregate particles was carried out and the experimental results were used to derive the interaction functions of the three parameters (the loosening, wall and wedging effect parameters) for extending the 3-parameter model to binary mixes of angular particles. Apart from the experimental results obtained herein, the test results published by de Larrard and those obtained by the authors in an earlier study were also used to validate the extended 3-parameter model.

The packing density results of angular rock aggregate particles were used to derive the loosening, wall and wedging effect parameters of the 3-parameter model. The parameters were found to be dependent on particle shape and compaction, as shown in the diagrams.Figure optionsDownload as PowerPoint slide