Investigation on the effects of asphalt mixes and their combinations on asphalt mix shear strength by 3D discrete element method

• Published in: The international journal of pavement engineering Vol. 24; no. 1
• Main Authors: Peng, Yong, Xu, Yi-ran, Zhang, Xiu-fang, Meng, Hui-lin, Lu, Xue-yuan
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 06.12.2023; Taylor & Francis LLC
• Subjects: Asphalt; Asphalt mix; Asphalt mixes; Computed tomography; Discrete element method; discrete element method (DEM); mix combination; mix type; Penetration tests; Rubber; Rubber modified asphalt; Shear strength; Three dimensional flow; Three dimensional models; uniaxial penetration test (UPT)
• ISSN: 1029-8436; 1477-268X
• DOI: 10.1080/10298436.2023.2251078

This study investigated the effects of asphalt mixes and their combinations on the asphalt mix shear strength (SS) by a three-dimensional (3D) discrete element method (DEM). The uniaxial penetration test (UPT) for testing the asphalt mix SS was succinctly depicted. 3D micromechanical models used to predict the asphalt mix SS were built through X-ray computed tomography and discrete particle model implemented in particle flow code in three dimensions (PFC3D). The effects of asphalt mixes and their combinations on the SS were analysed on the basis of these models. Simulation results were proven against laboratory UPTs. As shown, the presented simulation results were in good agreement with the laboratory results, and the deviations between them were below approximately 6%, and most were less than 4%. The SS of high modulus asphalt mixes was greater than that of SBS-modified asphalt mixes and rubber-modified asphalt mixes. The asphalt mix SS increased with the increase in aggregate size, and it decreased with the rise in void content. The double-layer asphalt mix SS was more remarkably influenced by the bottom asphalt layer. The crumb rubber content also affected the rubber-modified the asphalt mix SS. The rubber-modified asphalt mix SS increased with the rise in crumb rubber content.