Investigation of the force evolution in aggregate blend compaction process and the effect of elongated and flat particles using DEM

• Published in: Construction & building materials 2020-10, Vol.258, p.119674, Article 119674
• Main Authors: Wang, Sudi, Miao, Yinghao, Wang, Linbing
• Format: Article
• Language: English
• Subjects: Aggregate blend; Contribution to load bearing; Discrete element method; Elongated and flat particles; Force evolution
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2020.119674

•Particles with different sizes have different contributions to the load bearing.•4.75 mm is a transition point to discriminate the particles load transfer function.•Flat and elongated particles increase the vulnerability of particles to break.•Flat particles have more negative effect than elongated particles. Aggregate particles play an essential role in the load transfer of asphalt pavement. This paper documents an investigation into the force evolution in the compaction process of aggregate blend and the influence of the elongated and flat particles using discrete element method (DEM). Three typical aggregate particles, including a regular particle (RP), an elongated particle (EP), and a flat particle (FP), were selected and scanned by a 3-D laser scanner to get the 3-D images, based on which the virtual particles were generated in DEM software. Six gradations, three stone matrix asphalt (SMA) gradations and three dense asphalt concrete (AC) gradations, were selected and various contents of RP, EP and FP were considered in the investigation. The force evolution and the effect of elongated and flat particles were quantified using the DEM simulation results. It is found that particles of different sizes contribute differently to load bearing. The size of 4.75 mm might be a transition point for distinguishing the load transfer function of particles in the investigated gradations. Though the EP and FP have no effect on the evolution trends of contact force and contact number of each size particles in the compaction process, they have remarkable effect on the increased value of contact force, which increases with the increasing proportions of EP and FP, and some effect on that of the contact number with no fixed pattern. The FP exhibits more negative influence on the force evolution of aggregate blend than the EP.