Effect of the particle size ratio on macro- and mesoscopic shear characteristics of the geogrid-reinforced rubber and sand mixture interface

• Published in: Geotextiles and geomembranes Vol. 50; no. 4; pp. 779 - 793
• Main Authors: Liu, Fei-yu, Fu, Jun, Wang, Jun, Gao, Zi-yang, Li, Hao-ze, Li, Jing-ting
• Format: Journal Article
• Language: English
• Published: Essex Elsevier Ltd 01.08.2022; Elsevier BV
• Subjects: Anisotropy; Contact force; Edge dislocations; Fabric anisotropy; Force distribution; Mixtures; Particle size; Particle size ratio; Reinforcement–soil interface; Road beds; Rubber; Rubber and sand mixture; Sand; Sand & gravel; Shear band; Shear bands; Shear properties; Shear strength; Soils; Reinforcement–soil interface; Particle size ratio; Fabric anisotropy; Rubber and sand mixture; Shear band
• ISSN: 0266-1144; 1879-3584
• DOI: 10.1016/j.geotexmem.2022.04.002

As a new type of material for civil engineering projects, the rubber and sand mixture is widely used in roadbed fillers, offering environmental benefits over traditional tyre disposal methods. This study uses a large-scale direct shear apparatus to examine the interface shear properties of the geogrid-reinforced rubber and sand mixture, considering different particle size ratios (r), rubber contents, and normal stresses. Based on indoor tests, direct shear models of the mixture with different values of r are established in PFC3D, revealing the meso-mechanical mechanism of the mixture in the direct shear process. The results show that when r is greater than 1, incorporating a certain amount of rubber particles can increase the shear strength of the mixture. The r values of 15.78, 7.63, and 3.98 correspond to an optimal rubber content of 30%, 10%, and 20%, respectively. When r is less than 1, mixing rubber particles can only reduce the shear strength of the mixture. When the rubber content is low, the smaller the value of r, the greater is the thickness of the shear band. Furthermore, the normal and tangential contact forces are greater. The fabric anisotropy evolution law of the mixture is consistent with the change in the contact force distribution. •The interface shear properties of the geogrid-reinforced rubber and sand mixture are analysed.•The direct shear models of the mixture with different values of r are established in PFC3D.•The fabric anisotropy evolution law of the mixture is consistent with the change of contact force distribution.