Effect of Particle Shape and Fine Content on the Behavior of Binary Mixture

• Published in: Journal of engineering mechanics 2017-01, Vol.143 (1)
• Main Authors: Ng, Tang-Tat, Zhou, Wei, Chang, Xiao-Lin
• Format: Article
• Language: English
• Subjects: Discrete element method; Ellipsoids; Granular materials; Particle shape; Segregations; Shear strength; Strain; Technical Papers; Void ratio
• ISSN: 0733-9399; 1943-7889
• DOI: 10.1061/(ASCE)EM.1943-7889.0001070

AbstractThe behavior of binary granular mixture is studied by the discrete element method. This granular material contains large and small particles that are similar ellipsoids of different sizes. The size ratio of the major-axes of the large and small ellipsoids is 5. Samples of ellipsoids of different particle shapes have been created by pluviation method and the particle growth technique. Segregation is observed in samples prepared by pluviation method but not particle growth technique. Thus, nine very dense samples (≈ the lowest void ratio) with various fine contents (volume fraction of the small ellipsoids) are generated using the particle growth technique. The result indicates that the packing density is a function of particle shape and fine content. These very dense samples are then sheared under drained triaxial compression to very large strain to determine peak shear strength, critical state void ratio, and ultimate shear strength. Peak shear strength is affected more by particle shape than by fine content. The authors found that the effect of particle shape on the material behavior at critical state is not significant. Fine content affects the critical state void ratio but not the shear strength at very large strain.